#33 - Ian Walker: Enhancing Home Decarbonization and Air Quality - Practical Solutions, Behavioral Science, and Kitchen Ventilation

A conversation with Iain Walker

Joining me from California the leader of the Residential Buildings team at Lawrence Berkley National Labs and ASHRAE Fellow Iain Walker. Leader and developer on standards and technical committees for ASHRAE, ASTM, RESNET, IEC, the IEA and other national and international organisations.

Board member of IEA Annex 5 Air Infiltration and Ventilation Center for the US. And much besides.

He also happens to be one of the reasons I started this podcast. He is one of my favourite people to talk to in this industry. You come away energised, usually a little wiser, and almost always having spent a couple of hours talking about something completely different from what you expected. However, importantly, you wish more people could have had a chance to listen.

And that was one of the triggers for this, the Air Quality Matters Podcast.

We discussed the intersection of sustainability and air quality, got massively diverted onto cooker hoods and probably need to do a part two at some point.

Iain Walker - LinkedIn
Iain Walker - LBNL

Transcript

Simon: 0:00

Air quality matters inside our buildings and out, and I believe we already have many of the tools we need to make a difference. The conversations we have and how we share this knowledge is the key to our success. I'm Simon Jones and this is episode 33 of the Air Quality Matters podcast, coming up a conversation with Ian Walker Joining me, from California. He is the leader of the residential buildings team at Lawrence Berkeley National Labs, an ASHRAE fellow leader and developer on standards and technical committees for ASHRAE, astm, resnet, iec and the IEA and other national and international organizations. He's a board member of the IEA Annex 5 Air Infiltration and Ventilation Center for the US, and much more besides. He also happens to be one of the reasons I started this podcast. He's one of my favourite people to talk to.

Simon: 1:25

In this industry. You come away energised, usually a little wiser and almost always having spent a couple of hours talking about something completely different from what you expected, but, importantly, wishing more people could have had a chance to listen, and that was one of the triggers for the air quality matters podcast. We discussed the intersection of sustainability and air quality, got massively diverted onto cooker hoods and probably need to do a part two at some point. Thanks for listening. As always, do check out the sponsors in the show notes and at airqualitymattersnet. This is a conversation with Ian Walker.

Iain: 2:11

It's one thing to have like a really good idea or to write a good standard or to have, you know, something wonderful you could put in the house, but unless people actually do it, it doesn't really change anything right. It doesn't really change anything right. So what? One of the one of the key questions we're trying to ask these days is how do we get to scale with anything, whether it's air quality or decarbonization. How do you get this into like as many homes as possible? And some of that is about, you know, communication and understanding what it is that motivates people.

Iain: 2:49

So some of our more recent work has been we've been working with uh, we have colleagues, other national labs at pnnl, for example, our colleague chrissy antinopoulos there has been working with us on those sort of things where we do things like survey hundreds and hundreds of people to ask them questions about their perspectives on things like air quality and decarbonization and what might make them change their minds, what they like, what they don't like, what they've heard, what they haven't heard, you know what would help them to make a decision and sort of get into that. I'll call it human behavior aspect of things. So we are not behaviorists, right, but as people who are trying to figure out. You know, what R&D questions should we answer as researchers? It's kind of important to understand are we asking questions that are the questions that people making decisions in our case individual homeowners right, are those the questions they're asking or not? Because if we ask the wrong questions, from an R&D perspective it won't be helpful. Right, we'll have answers to questions people are not asking. And similarly, when people ask us questions, we'll be going. I don't know, we didn't study that so we can't help you.

Iain: 4:02

So there's this sort of interesting aspect about how we relate our workers, researchers, to how does, how, would that get implemented? Right? And you know, sometimes that is our work is to advise policy or it's technical background for changes to standard, where standards, where that that's like the, where we're changing requirements, you know what must you do, say in a, in a building code or building regulation, right? But some of this, some of these new ideas, are a little more subtle in that, um, it's trying to figure out how would you present something or persuade people to do something else in their homes, right? Rather than saying you must do it because the law says, when you're building a new home, how are you going to change the home you're currently in. I persuade people that that might be a reasonable thing to do. Anyway, that's sort of like a very interesting area. We're just getting started on that, to be honest, and of course behavioral scientists have been all over these sort of issues for a long time, but we haven't really had this situation where, you know, we've had sort of effectively the technology r&d people, which is you know what we do at national labs, talking to those people as well.

Simon: 5:24

Anyway, that's sort of, if there's any other sort of big area that's just starting out, I would say that is sort of a very interesting I think it's indicative of this coming together of disciplines we're seeing more and more in the sector, because public health has been involved with behavioral scientists for years, so like they understand that relationship, but there's much less of that in the built environment, engineering end of things, understanding the behavioral side of it and that's a part of the conversations I've been having a lot recently on the podcast. Actually is that trying to understand more about the behavioral science and the citizen science of this stuff? Uh, there was a great quote from uh douglas booker, who's just I've just did the podcast this week with him, and it's that saying uh, no research about us without us, which I thought was a brilliant concept. You know that that we shouldn't be doing anything about us without us, which I thought was a brilliant concept. You know that that we shouldn't be doing anything about us without us being part of that citizen science piece. And then I had a really interesting guy called dan on uh, who's a ux, ui expert, user experience expert, and he was saying a lot of this stuff is actually just product development and marketing. A lot of the principles you're trying to understand within the built environment is just about understanding needs and framing and language. Yeah, like a lot of the answers we're looking for is buried within what happens in the commercial sector the whole time, that whole ux ui process and what that is, what it is to the built environment.

Simon: 7:13

So I think that whole area is fascinating, and the one I'm really digging into at the minute, which is a discipline and of its own, is communicating risk. You know, how do we, how do we communicate the risk of something that's so esoteric and often long term to the general public or to individuals in a way that can stimulate purchasing decisions or behavior change or habit change? And you know we talked about we'll probably talk at length about cooking later on and cooker hoods. You know we're not trying to get people to stop cooking in their homes, but we're almost certainly going to require a behavior change or a habit change from people to start using equipment they just don't use at the moment, like cooker hoods. How do how do we frame that risk for people effectively?

Iain: 8:07

I think that whole, that whole area of communication and framing is fascinating, absolutely fascinating yeah, yeah, I agree, and it's it's sort of permeates all the work that we do, and I I think that, um, even research funders in the field that I work in are becoming more aware of that, and I'll just give you one quick example. We're just about to start a brand new bit of work for the California Energy Commission, where there's been a lot of work done to try and persuade people to electrify some of the end uses of their homes here in California. The challenge is not that you can't buy a great heat pump to heat your house and make hot water. That's kind of trivial. You just go get it right. That's not the hard part. And those machines, they're pretty good, actually they're, I mean, they really do they say they're going to do.

Iain: 9:06

The challenge is that it's not easy for an individual home uh, homeowner or occupant to um figure out what to do, like who to call and, uh, how do I make decisions about? Do I do it all at once? Do I do electrify everything in my house all at once, or should I spread it out? And what sort of questions should I be asking the electrician or the contractor who's doing the work? Because this is a new thing and people don't know. So, anyway, the work that we're going to do for the Energy Commission is to produce a free tool that will be free to use for anybody who wants to use it, that guides people through the process, tries to answer their questions and sort of just to the point you were making. This isn't necessarily risk analysis per se, but it's about people to provide the information people need to make decisions and help them and make the process easy.

Iain: 10:04

I think making it easy is the key thing. Something is difficult, no matter how great it is, people won't do it, and the challenge we have, at least in the US, is that you get sort of standards of practice. What do your local contractors do when they do something in a home? Well, if that's what they do, everyone you call is going to give you the same answer, which is do what we've always done and not change. So people need help in the process. That isn't going to be easy for them.

Simon: 10:38

Yeah, big changes nearly always require trade-offs. It doesn't mean that on balance it's a negative trade-off or a positive trade-off, but significant changes in the way we heat or electrify or manage our built environment nearly always require some kind of trade-off. We've seen that, particularly in at this part of the world with heat pumps, that one of the big obstacles has been stored hot water. You know, if you're on gas or oil and you've got instantaneous hot water through combination boilers, switching to heat pumps and having stored hot water for the first time in your life can be a trade-off. You know, you've always been used to turning on a tap and having as much hot water as you need and all of a sudden you're faced for the first time in your life with running out of hot water. If the teenagers have got in before you now, if you've grown up with stored hot water, that's not new to you, it's not a problem. You wouldn't see it as a trade-off at all.

Iain: 11:42

But that's a really good example of uh, by not understanding and having the language and the framing for people of heat pumps has presented real problems and people will absorb one trade-off, maybe two, but if there's two or three or four, all of a sudden, once negative sentiment starts to creep in to some of these changes, they can be really difficult to persuade people, you know, and yeah, I, I think you're right and I mentioned earlier this work we've done where we've um surveyed people to figure out what it is they they think are going to be issues and, frankly, the the some of the key answers that we might call see as barriers or whatever are, are ones where it seems obvious, but, as if you're a technology developer, it's not the sort of questions you ask. So I'll give you a few examples. When, when we talk to people about home electrification, they ask questions like well, who's going to install this new thing and how do I maintain it? What do I have to do? Who's going to maintain it when it goes wrong, who do I call? And there's all these like super practical things where for the house they have, now they know the answers to all those questions, but we're telling them, oh, we're going to change, put in these new things, and now they don't have answers to those questions. They don't know who to call.

Iain: 13:13

And there's obviously the classic questions. They're always asking these things like are my bills going to go up or down? Right, which is always a really hard one trying to answer, because often the engineering analyses that get done are, say, which is always the really hard one trying to answer, because often the engineering analyses that get done are, say, population-wide to informal policy. So you say, well, if we do this, in a million homes on average, everybody's going to save five pounds, five euros, five dollars a month, whatever the number is. But it doesn't mean every single home does.

Iain: 13:47

And the challenge is trying to. You mentioned risk earlier. This is a risk analysis, right, we know that some homes well, guess what? It might be the case that actually you're going to go up that five euros or five dollars or whatever, or five pounds, five pounds a month, and trying to be upfront with people about that, because you don't want to mislead people, but do it in a way where it doesn't panic people. They're like oh, you know, you can put people very easy with very small numbers, right? People looking for a reason to not do something. So those sort of questions, you know we have to have ready answers for and I think we're sort of realizing that it's. It's not enough to say, well, just buy the thing and install it. That's, that is not satisfactory, that's not, that's not going to work.

Simon: 14:34

Right, we have to be able to answer these other and you're doing quite a bit of this work at the moment. Um, I'd be interested to get your perspective on how you see that intersection of air quality and decarbonization. Um, because they do go hand in hand. Um, there are both co-benefits of electrifying the home. Um, there's co-benefits of making buildings more airtight and sealing them from outdoor pollution or having more control of ventilation. But equally, there are challenges with underventilating buildings or unintended consequences of certain things. Are you seeing quite a bit of crossover between those two disciplines with the stuff that you're doing?

Iain: 15:18

the. The classic case is that for many years, we've been trying to build not just homes but almost all buildings in a way that they're more airtight, and usually we mechanically ventilate them with fans in some way, but it's in, it's controlled right. We have controlled ventilation, which really has brought down the amount of heating cooling. We have to do quite significantly so great thing for energy efficiency and all of that, and and in fact, when we're looking at taking homes and electrifying them, one of the challenges is particularly for older homes is that they are not very airtight. They're still quite leaky, and so one of the things that we're trying to get people to do is, let's say, you want to replace a furnace or a boiler with a heat pump is to do things like well, maybe we should put a little bit of effort into improving the building by things like reducing how leaky it is and maybe insulating it if it's not insulated, or adding insulation, particularly, I think, in attic spaces. So why does that matter? Well, that's effectively reducing the load, it's reducing the amount of heating you have to do in the winter and the cooling in the summer, which means you can purchase a smaller piece of new equipment, and that saves you money up front because a smaller capacity, a smaller device it just simply costs less money. It also makes it easier to install because it's often physically smaller, right, it's easier to find the space to do it. So there's sort of a link there with you know. What you invest in reducing the need to heat and cool a home gets reflected in some money that you save when you're installing the new equipment. And there's some balancing to be done there, and so I think there's that connection simply from what engineers would call the building loads, like how much heating and cooling do you need to do to be comfortable in this space? All gets connected.

Iain: 17:27

And one more issue there that is a kind of a new thing we've talked about energy efficiency in buildings. It became a big thing in the late 70s with the energy crisis and we've talked about energy efficiency for a long time, and I think one of the new things we're very interested in is what we call you might call it power efficiency, or a phrase we're using is low power electrification, and what I'm talking about there is it's not just how much energy you use to heat and cool your home and make hot water, for example. We're also talking about what is the peak power requirement and if you can keep that low. That has a lot of implications. Firstly, if you keep it low enough, you won't have to upgrade the electric system for your home and you won't have to change the wires that connect your home to the street, which again saves money and it saves time and it just makes it easier to do. The savings there are tremendous and honestly much bigger savings than the idea I talked about a few minutes ago about if you buy a smaller heat pump because the load's lower.

Iain: 18:42

Reducing the peak power so you don't have to replace all the electric infrastructure in your home is just such a huge savings up front and also looking to the future, we're trying to do electrification in a way that I will say is kind to the electric grid. By that I mean we don't want to really massively increase the load on the grid because that will cost us a lot of money in the future. If we have to replace all the wires in the country or add a whole second set of wires or build more power plants. That takes a long time. So there's big time delays, which means that that will delay any of the things we want to do. There's already places in California that are denying people where they're like. I'm sorry, our electric system is at capacity. You cannot electrify your home.

Iain: 19:35

That's already happening, and so we want to avoid that. Plus the future costs, at least in the US system, where we have privatized electricity, anything they invest in new wires, new transformers, new substations, new generating plant that just automatically gets passed on to the ratepayers and you will pay more for that electricity in the future. So there's massive future cost savings as well if we can limit the power. I know we got off on a tangent here where from air quality, but these things are all connected. Right, you do this one thing about air tightening and it has all these subsequent consequences that are very interesting in terms of the influence they have um from a policy perspective and also for individual homeowners. Even thinking sort of bigger picture about do we have the capacity in the electric system in our countries to actually do all this electrification?

Simon: 20:33

yeah, they're fabulously cyclical conversations because you know you introduce embodied carbon and making nuanced decisions on the type of products or materials that you're putting into the home. Or conversations that are happening around my circle at the moment about whether fabric first is the right choice or whether it's they call it fabric fifth. Where actually the trouble is with changing the fabric of the built environment is that requires stakeholders to go along a process that can take some time and isn't moving fast enough objectively. So one of the advantages of heat pumps is you just get people to mandate that when a boiler breaks it's replaced with the heat pump. You're not bringing consumer decisions into that process. You're decarbonizing the heating of homes without having to get people into long retrofit programs and decision making processes. Even better, decarbonize the actual grid itself and then you remove the consumer completed from the process. So like it's an incredibly complex web of like what.

Simon: 21:47

What moves the needle here when it comes to decarbonization and smack bang in the middle of that is a conversation now about having it focused purely on energy and not on healthy, sustainable buildings. Doesn't bring in a lot of kpis and metrics that could be quite valuable for people to make decisions on decarbonizing their homes, because that's been one of the challenges is you. You ask people that have had work done to a decent level in their homes. Very rarely is the energy the thing that they talk about. It's the comfort and health and well-being, and you lose that conversation track if you don't have health and well-being. Sustainability in the center of the conversation piece is that. Is that something you equally find where you are? And also, just for my sense, when we're talking about homes, instinctually are you talking about californian homes or do you? Because when we talk about the states, obviously it's quite a spectrum in north america of environments. Um, for context, like when I'm just discussing homes and decarbonization with you, ian, are we talking about your part of the world?

Iain: 23:07

Oh, I thought you were going to say more broadly, across the world, which is an even wider question. So, to answer you directly, the work that I do has a strong US or North American, if you will. Has a strong US or North American if you will focus. But, frankly, a lot of the things you've just mentioned, I think they're universal truths this idea that people don't really care what heats their home, so long as their home is comfortable and so long as it's affordable. That's the two things people want. They want to be comfortable in an affordable way. The actual device that does the heating, frankly, nobody cares, right? And similarly, for hot water, right, people want hot water to come out the tap when they turn the tap and do that in an affordable way. And what makes it hot? Who cares? Right, you're providing a service, right? That that's, that's the key thing. And and that, for engineers who are all about what does this piece of equipment do? That sort of uh, that's not how they think, right, it's a different way of thinking about the world. But that but're 100% correct. It's universal all over the world. It's true that that's how people think about these things.

Iain: 24:30

But in terms of types of housing, we're looking at all kinds of homes.

Iain: 24:36

In fact, in the US for anything where you know, like I'm a researcher, our funding agencies are very much emphasizing that we are definitely going to be addressing, say, multifamily homes, particularly low income. Similarly, we have something called a HUD manufactured home, which is a trailer home, if you will. I can't remember what the UK terminology is, but in theory you could move in. It could be on wheels, but as a matter of fact, the only time the wheels are on it is when it came from the factory and it's put into place. You have, you know, there's like holiday camps we can go that are full of these things in the UK. So I think you're familiar with that sort of housing. Well, in the US there's a lot more of it and again, it's very inexpensive, right, and often the people living there are on lower incomes and it's a challenge for them. It's not going to work if we electrify their homes and double their heating bill. It's not going to work for them because they don't have the money, right.

Iain: 25:46

So a lot of what we're doing is focused on making sure that what we're doing is affordable and affordable across a whole spectrum of the population, right. It's not good enough to just look at, say, single-family homes or owner-occupied. We've also got a. Renting is just the biggest challenge. When we talk about what are we going to do about adding ventilation, homes from an indoor air quality perspective, traditionally that has always been challenging. And now, when we talk about heating and cooling and water and changing all those things, if you rent your home whether it's an apartment or a flat or a house you often don't have any control over that whatsoever, and so there's this disconnect between who lives in the space and who would potentially benefit and who owns the property and can make the decisions. Traditionally, the issue has been in energy efficiency programs, where the person who would benefit with the lower electric bills or the lower fossil fuel bills would be the occupant, but the person who would pay would be the person who owned the building, and that classic disconnect has been debated to death forever and it's very, very hard to overcome. And and now we sort of have a a a similar thing when we're talking about replacing heating and hot water systems with heat pumps is who benefits, who pays? And and frankly a big concern in the us is is sort of the reverse of the old problem where, let's say, your landlord does put a heat pump in, but the bills go up. The tenant had no say in that decision and yet now they have to pay more.

Iain: 27:39

Or the classic issue if you have a multifamily building with central hot water or central heating or central ventilation, central systems, where those are in effect included in the rent, there's not a separate bill for those.

Iain: 27:54

But at least in the US, a lot of multifamily buildings the electricity for each unit is billed separately. So if we now go to an in-unit heat pump, the occupants, the renters, are now paying for the heat where they didn't pay for it before and of course in theory that means their rent goes down right because they don't have to pay to run the central system. But in effect, of course that will effectively force the building owners to reduce the rent because the central systems are not operating anymore. It's all on the individual, and dealing with rental properties is very, very hard in these things we do, and whether it's installing ventilation systems, going from central ventilation to ventilation individual units or whether it's doing heating, cooling and hot water. So you asked about the housing types. It's all of them and some are more challenging than others, and also it's not just the architectural differences, if you will, and the construction differences these ideas about who owns what, how we help renters is hugely challenging and if I had an answer, I would tell you but I don't.

Simon: 29:17

I mean it's difficult enough when what you're doing is quite well understood and measurable. You know, energy outcome is quite definable in a lot of cases because there's a bill at the end of it. And but when you talk about split incentives and air quality, boy does it get complex quickly. You know now, absolutely you know there is a, there is a, there is a complexity to comfort and energy for sure. You know we've seen, particularly in the less well thought out programs. Really, all that you've done is made buildings more affordable to heat. It hasn't actually brought bills down, you've just increased the average temperature or reduced the average temperature, depending on where in the world you are.

Simon: 30:03

But with air quality quality, it's much more nuanced and difficult, and I think that's where you've been at the forefront for quite a while. And is that trying to understand where we are with the measurability of air quality? And I think we're even. We're even seeing organizations like ASHRAE now focusing in more and more on metrics of air quality as part of standards, aren't we? It's that move to saying, okay, well, how do we define air quality? If we're going to start measuring it and defining outcomes, we're going to have to start framing this in a slightly different way to likelihood of discomfort, type metrics yeah, I mean I think there's this sort of three core issues around air quality and, um, you know, some of it is a historical.

Iain: 31:02

You talked earlier about cooking. Well, historically, when people first moved into caves, one of the big problems was those caves filled with smoke when you tried to cook, and there are definitely old caves that have vents in them to vent out the cooking. Then, when people started to live in huts and so on, they all had an opening at the top to smoke out or they did it. I mean, just amazing. I guess we would call it clever engineering these days about using different construction materials for the roofing that would actually effectively allow the smoke out but wouldn't let rain or snow in. I mean mostly using reeds and things like that. But this idea of venting our cooking has been around forever and certainly we sort of lost that thread somehow. Certainly in the US and somewhat in the UK, ovens for the longest time had a flue pipe that came out of them and vented to outside. We did not vent into the kitchen for the cook and everyone to breathe. I live in an old house. When I remodeled the kitchen, right there in the wall was the circular thing where the original cooking device vented to outside, but somehow people got persuaded oh we don't need to do that and we stopped venting. Well, we gotta, we gotta vent. Right, we should know we should never have stopped venting our kitchens. That was a mistake, right, and and I don't want to I'll use cooking as an example, but it's kind of true of other indoor air quality things too.

Iain: 32:47

There's three components going on. The three components are that, you know, moisture is a big one, right, we've all had the experience of cooking in the winter with cold windows and moisture running down them and so on. And so controlling moisture has always been an issue for cooking and for air quality in general. Right, venting away the moisture Human beings, we're emitting moisture all the time. The things we do, like cooking and cleaning and everything emits moisture. We've got to have moisture control. Right, that's been an issue for ventilation, air quality, forever. We don't want water running down our windows and rotting out our window frames. We don't want mold growing because we've got high humidity and dwellings, okay. So moisture is the classic one.

Iain: 33:30

And then there's sort of this idea about what we might call perceived air quality, which is, uh, you know it's kind of aligned with comfort. It's about how do people feel about a space. Do they feel it's stuffy or whatever, and that that's a little more subtle. But but this was sort of studied quasi experimentally quite a few years ago and it is the basis of things like ventilation standards. Honestly, it's this idea that you need to get rid of the, I'll loosely say, human bioaffluence. I won't get into any more detail on that, but this idea about stuffiness is things that it's almost a subconscious thing where a place, the air, just does not feel right and people have different reactions to that, different levels and so on, and so you need to ventilate for perceived air quality. And then I think the one that we often talk about the most is indirect quality and health right, which is what is?

Iain: 34:28

in the air that might make you more or less healthy. I mean the classic contaminants. There are things like particles that you can breathe, oxides of nitrogen, ozone there's a whole host of of things, but you know, the ones that come out on top are things like particles, oxides of nitrogen formaldehyde is another one quite a few of your listeners may have heard of and those have health impacts. Some are known better than others, right, but at least for the leading ones there's been enough medical studies done that we know it's not just correlation. We actually know the chemical processes happening in people's bodies and why it's important, and large-scale epidemiological studies have been done. We know enough about those health impacts that, in effect effect, you could monetize them. And in the US anyway, the Environmental Protection Agency and others have tried to develop frameworks for doing exactly that, where you can say, well, if you have this level of particles, it's this much of a health hazard. We can convert that into things like overpopulation how many more hospital visits is that? You convert that into dollars and so on.

Iain: 35:47

And there is a movement that's gathering strength that says healthcare providers, rather than any other entity, might be the ones who are most interested in improving air quality in homes might be the ones who are most interested in improving air quality in homes. Because, particularly if you have a publicly owned healthcare system where everybody pays in and benefits, if you can do things like halve the number of people going to the emergency room with asthma attacks, that can just simply, simply you can monetize that and say, well, we're going to save so many million pounds, euros or dollars a year because we have this program that improves air quality in low-income neighborhoods, for example, because we put in better ventilation or we put better in. In the us we do a lot of heating, cooling by blowing air around, right, so we can filter relatively easier. I know it's harder in Europe where you heat with hot water. You'd have to have some standalone filtration system, but it's not beyond the wit of man to do that right. You can have subsidies from things because we can monetize the health impacts right, and this has been done for a long time with outdoor air quality. Actually, it's why we have outdoor air quality standards.

Iain: 37:12

Honestly, there was this idea that we could monetize or we could. You know it sounds macabre, but we can count the number of deaths right If we have this level of NO2 or this level of particles in outdoor air, for example, we can say that's so many excess deaths a year. I'm sure your listeners are familiar with that sort of terminology and have seen it before. But it allows us to make decisions, or at least you mentioned risk analysis earlier you can say well, if we do this, the risk is that that happens, if we do this or don't do that, we get some other outcome and you can evaluate things that way. But that's why we have outdoor air quality standards.

Iain: 37:49

Certainly in the US and particularly California kind of led this about trying to limit things like particles and NO2 in the ambient. The challenge has been we don't have what I would call the equivalent for indoor air. Now you can make the argument that well, a lot of what's in the indoor air came from outside. Right, I think, particularly things like particles and NO2, unless you have fuel combustion in your home, if you're living in an all-electric home, it all comes from outside. And you know we've done the research communities and lots of experiments to determine things like the average indoor concentration of outdoor particles is like half, and so we kind of know this from measuring thousands of homes. So again we can sort of evaluate the impact of outdoor air quality on our health.

Iain: 38:44

We don't have indoor air quality standards and I think we might get there one day, but it does provide us a challenge, right, because it's always easy to change building codes and standards and regulations. There are people who don't want to change and they can rightly say you can't use these numbers because they are for outdoor air. And now we're talking about indoor air quality and we have these circular arguments that the standards committees I sit on we have exactly these discussions right about. Can you actually legitimately use a number of the World Health Organization developed for outdoor air, indoors, so on and so forth? It's, it's just quite challenging, but at the same time, it does allow us to do as you were suggesting, which was to you can do a risk analysis so you can say how much will everybody benefit if we, if we do this or do that, and how much whether that's ventilating or air cleaning or sort of circulating back to where five minutes ago, if you vent your cooking cooking is a great source of things that you don't want to always be breathing.

Iain: 39:56

Now I understand there's a trade-off here, right? I mean, if you're, if you're frying a nice steak or something in in garlic butter. I mean, it smells fantastic and you know it's part of a culinary experience and I would never deny anybody that. But you also have to understand that when you fry that steak in garlic butter, there's a huge plume of contaminants that come off that, long term, can have health impacts. It just is true, right, and so it's a trade off, it's a balance, it's a risk analysis, and I would be, I would argue that you should definitely not change what you cook, but you should turn on your cooker hood when you do it. And one of the great benefits of being human is that, in terms of odor the things that matter for cooking you don't need very much of it in the air to sense it. We have a great nonlinear thing stuck in our nasal cavities that is fantastic at smelling the delicious thing you're cooking, even though you might have vented 90% of it to outside. I believe you can get almost all the health benefit without detracting significantly from the cooking experience by turning on your cooker hood.

Iain: 41:08

I think that there are other challenges with things like kitchen venting around. Why is it so noisy? Right, when we survey people, when we go into a, we study this in homes. We're always doing measurements in homes all the time. I'm always asking people, you know, why did you not turn on your cookout? Because we monitor people's kitchens to see when they're cooking.

Iain: 41:32

Do they vent? Sometimes they do, sometimes they don't Mostly, not, to be honest with you. And the number one reason is people don't think it's necessary. People do not connect this idea that cooking might actually put contaminants in the air. And second is the fan is just too noisy. And you know what? People are not wrong, they are noisy, right. And so we're working with manufacturers and rating organizations to try and figure out other ways to redesign the herds and give them a new rating which will make them quieter at the operating speeds we like, and things like that. So there are sort of there could be some technological advances there, but it's a real issue, right, it gets back to the sort of provision of service, if you will, everybody will be like yeah, yeah, please vent my kitchen, but I still need to be able to have a normal conversation in the kitchen while I'm doing that. Right, I don't have to be shouting over the racket of a fan.

Simon: 42:33

I'll have you back to the podcast in a minute. I just wanted to briefly talk to you about 21 Degrees, a partner of this podcast, formerly the Green Building Store. They were founded in 1995 by three exceptional building professionals. The company grew out of their frustration with the poor availability of ecological building products. I've known them for years as the go-to company in the UK for end-to-end design-led MVHR systems. We spend the majority of our time in our homes so they should be the best. They can be comfortable and healthy to live in, with exceptional efficiency, In fact, life-changing homes At 21 degrees. You won't find a more trustworthy, straight-talking, passionate about what they do and approachable group of people. I speak a lot about the performance gap on this podcast and what we can achieve if we value ventilation highly enough. 21 degrees embodies that sentiment for me. So if you're building a home, looking to install ventilation or need to talk to experts in the field, I can't recommend them highly enough. Links are in the show notes at airqualitymattersnet and you can google. We Are 21 Degrees. Now back to the podcast. That that's interesting. So you're saying those conversations are starting to happen with industry now about realigning what the value of that product is because, like cooker hoods.

Simon: 44:18

There's there's only two decision making processes with cookers, as far as I can see. One is aesthetical is it a metal one for my modern kitchen or is it a wooden one for my country? Kitchen type decisions. Or, if you're a developer, what's the cheapest piece of shite I can put in? Um. That's humanly possible because the, the quality of the cookahood, will have no impact on how much I can sell this kitchen or home for. Therefore, why would I invest any money whatsoever in providing something decent? And the net result out of that has been I have never seen a specification for a cooker hood because nobody cares and has ever asked for one. Quite frankly, they the only thing that they have to do is comply with whatever the national regulations are for the, the flow rates for cooker hoods, if that country has one um. But there's no interest in the acoustics or the capture efficiency or the performance of that system and as such they end up being horrible, rattly metal tin boxes with the cheapest fan that you could possibly buy going into it. So as far as low hanging fruit goes for product development, there must be an awful lot there At the very high end. I see the Bosches and the Mele's and some of the fancy cookers starting to have a bit of demand control, that they'll automatically come on when there's cooking and they'll talk about them being quiet, that they'll have some acoustic ratings. But you have to be prepared to spend four or five, six hundred euros on a cooker hood in order to get that, which most people aren't. I think personally, and I imagine I'm probably pushing on an open door with you.

Simon: 46:15

Kitchen ventilation is going to be one of the most fascinating areas of public health development in indoor air quality over the next decade or so. There's so much focus on the harm that PM and cooking pollution can do. There's so much evidence building for that and the products are starting from such a low base that there's so much room for innovation and upselling and development that it could be a really fascinating area for people that are prepared to get on with it and do it and get ahead. Can you imagine? You know brilliant capture hood efficiency and demand control. You know that comes on when detect certain types of cooking even and, you know, is able to do that silently and with power. You could have some really fantastic products potentially. Yeah.

Iain: 47:21

You basically provide a great synopsis of the state of the art. Right, and you're right, I think that there is increased attention being paid to ventilating of kitchens, and for good reason. Right, it is actually sort of. One of the principles of good air quality is what we call source control. By that we mean remove the contaminant at its source, before it mixes in the house, because once it's mixed in the house, it gets even harder to get rid of. You have to move a lot more air. So if you're cooking, having a hood over the cooker is absolutely the way to go. It's the same, you know.

Iain: 48:05

I draw the analogy with formaldehyde. One of the reasons we measure much lower formaldehyde in homes than we did historically is not because we're doing a fantastic job of ventilating away formaldehyde in homes than we did historically. It's not because we're doing a fantastic job of ventilating away formaldehyde, it's because the products we bring into our homes have had the formaldehyde content regulated to be much lower than it used to be, so there's just less of it getting emitted. Yeah, now you can't really do that with cooking, right? If you're, I get it back to you know, frying the steak again.

Simon: 48:35

You've got to fry the steak.

Iain: 48:35

There isn't like a way to have low emitting steak, that's not a thing, right, but we can vent it better. And you asked me if you know about ongoing work in this area and I'm currently a member of the U's a us national standard. It's called ashray standard 62.2 for ventilation of homes and it has a specific section. It actually talks about venting kitchens and cooker hoods and so on and, as you mentioned, it says you have to have there's a minimum airflow. You can obviously go higher, but there is a minimum airflow requirement. That's the current specification. But it also includes some noise requirements, both for whole dwelling ventilation and kitchen ventilation, and we're in the process of looking at those to see. You know, do products actually meet this? Do they meet it at that minimum airflow, or can you get them to meet it at a higher airflow? That might be better ventilating your kitchen? And so there's actually a sort of a subgroup of people involved in that standard, working together with manufacturers of cooker hoods and rating and certifying agencies to think about. You know, do we need new test methods? Can we adopt test methods? We've already gotten use them better. Can we change how certification works? And an example of that is, if you do a sound rating at that minimum airflow, which is 100 cubic feet per minute or about 50 liters a second, it's not too hard to be quiet at a low airflow for a fan and a duct system. But let's say you enter two or three times that airflow in the same device. It gets noisy. It gets noisy and that's a challenge, because what we, what we know from a lot of experimental work both in the laboratory and in homes, is probably not surprisingly the higher the airflow, the better you exhaust those contaminants from kitchens. Um, but and you raised this point, simon is, if you have everything, have the same airflow, different hoods do a better job of capturing the pollutants and throwing them away outside. This idea of what you call capture efficiency is exactly that right For any given airflow. What fraction of the contaminants are removed from cooking? What fraction go into the kitchen and the rest of the house? We call that the capture efficiency. So, and as you said, ideally what you want is a high capture efficiency, so low contaminant levels in the house. It should be at as low an airflow as possible in order to be quiet, because the movement of air is what causes the noise, and that's a challenge, but we have measured quite a lot of different cooker hoods and there are definitely cooker hoods that work much better than others, based on things like their geometry, how much just the physical size, honestly like how much of the cooktop is covered.

Iain: 52:00

What we've learned is that it's much more challenging to get rid of the contaminants when you cook on the front burners and the front heating elements compared to the back ones, for obvious reasons. Here I'm talking about, you know, a cooktop that's mounted against a wall or something. We've got a wall at the back of it, but as a cook, it's much more awkward to cook on those back burners than the front ones, so people don't do it. So we've got this point where you have a cooker hood that might have great capture if you're cooking on the back burners, but you don't use them and so it doesn't work so well. So the way you get around that is, you have to physically have a larger cooker hood.

Iain: 52:36

Then you have compromises about well, they put a big cooker hood. You don't want people banging their foreheads on the hood, right? This is this is this is very practical, right? So you have to change the height of the cooker hood and something else that we know, again experimentally, and probably makes you know from a common sense point of view, this makes sense also is that, um, if you move further and further away from the cooktop, mount it higher and higher and higher, you're losing capture efficiency again, right, because the plume of contaminants gets to escape, and you know. So.

Iain: 53:13

There's a lot of factors going on, but the bottom line is we're working with manufacturers and radio organizations, as I said, to try and develop better cooker hoods that do a really good job of ventilating your kitchen at lower air flows, so using less fan power, you know, if you care about that, it's quieter, and so on. And also working with the rating agencies. Because you mentioned marketing, a key thing for manufacturers is that if they make a change to a product but it's not reflected in the rating, it's hard for them to get credit, right, uh, because there's there's a a disconnect. People just generally don't trust manufacturers of anything. To be honest, right, it's all marketing, but if you say something is rated in this way, to a standardized way, that is something that is kind of more a bit more so, do you?

Simon: 54:05

think it will move more towards kind of like a cadar rating for cooker hoods, that there's a rather than a flow rate. Necessarily there's a. There's an amount of pollutants that are emitted in a test laboratory and you're judged on the capture efficiency and the noise levels in order to do that and you can get ratings. So there'll be a, a standardized way of of capturing that number for people, so that so the the onus on development and product development will be to get better and better capture efficiency, at lower and lower fan speeds, at quieter and quieter sound levels, and encourage that innovation. Um, so there's a metric that people can be judged by.

Iain: 54:54

Yeah, absolutely, because without that it's very difficult for product manufacturers to figure out you know what is the best plan for us to get there. And there is actually a test method in the US anyway, promulgated by ASTM, the American Society for Testing Materials, that us researchers have been using, product manufacturers have been using to evaluate their product, and it's a laboratory test. You don't go to people's houses, so it's a very standardized test procedure where everything has a fixed geometry and we fix the temperatures of hot emitter plates and all that sort of thing. So the idea is you want something that's kind of repeatable, right? So it's the same every time standardized testing. And we're currently working to make that an international standard with colleagues from Asia and Europe and we're sort of partway through that process.

Iain: 55:53

I would guess like a year from now there'll be an international standard available for this that will be both acceptable and applicable to Europe, asia and the rest of the world. If we can get everybody testing the same way, that's a huge advantage really for manufacturers, right? If they know I build this product, I test it once, I can sell it in any market in the world, because we've all agreed this is the test method that we like that. We're going to say this is how we're going to rate things. That's a huge bonus for them, because what they don't want is a patchwork where every country has its own test and their products have to be tested 30 times because that's really costly.

Simon: 56:38

Yeah, so we're trying to end up we've had with air cleaners where nobody really knows what the standard method is and what the best way to do it is.

Simon: 56:47

And if I could have one ask in that process, if you have any influence here is that there's also a standardized way of presenting that data, because if we've learned anything from trying to interpret things like fan curves, if you leave it up to marketing departments, it's a flipping minefield trying to determine performance of this product versus that product, because there's no, you can't compare apples with apples. So it'd be great to have some kind of standardized displaying of technical specifications and information, because that means then people can make informed choices based on the information, if it you know, but the level below the label, the, a rating or whatever it ends up being that there's some standardized tables or something that means people can see how it performs at X and how it performs at Y. It'd be very good.

Iain: 57:43

So that's a good idea. Classically, that has happened by getting rating agencies to agree on labeling. Test methods generally don't do it, but one of the things that I'm working on with and it's not just me a bunch of people involved in this um again from manufacturers, rating agencies, other researchers, the um. What we're working on is exactly that sort of coordination where we have the rating agencies involved from the very start in developing the test method. So this is something that we should go to the rating agencies and say please use the same symbols and layout and text and font. So when I'm at the shop and I'm looking at a stack of boxes, the things that I'm looking at are all the same. That would be really cool. I do want to touch on one more thing that you mentioned, which is all of this is moot if none of these devices get turned on and we know that they're not always turned on when they should be.

Simon: 58:48

Chicken and egg, though, isn't it? Because they're not turned on because they're horrendous. So if we can make them less horrendous, there's more likelihood that they'll be on, or that they're not turned on because they're horrendous.

Simon: 58:55

So if we can make them less horrendous, there's more likelihood that they'll be on or that they're automated. You know, when we look at the hierarchies of control, when we get down to engineering controls, the preference is always automation. So if you take some of that choice away from people, that at least stuff is coming on when a ring goes on or a hob goes on, sure.

Iain: 59:15

But I would argue that we'll talk a little bit about automation in a moment. But you should only automate if the thing that happens automatically is acceptable to people. So yeah, if the thing that happens automatically is an incredibly noisy fan is turned on in your kitchen, that drives you crazy, that's not good automation right. So we kind of have, like some we need to coordinate this right. We can move to automation once we have quiet, efficient operation right, and so we're sort of doing these things in parallel right now.

Iain: 59:54

So the automation part of it there's been sort of semi-automation for very, very high-end, expensive devices for quite some time. They were mostly, I would say, a safety measure rather than a ventilation measure and they were based on things that are very simple, like measuring the temperature in the hood and if it got very high it would automatically turn on in high fans because the concern there is something really bad has happened, like there's something on fire on the cooktop and you want to vent away that fire and not overheat your cooker hood. So that's why it's temperature based right. So that was sort of a a safety measure rather than a indoor air quality measure. But that idea has been around for a while in high-end devices and, um, the the next generation, if you will are sort of under development.

Iain: 1:00:52

There's a few hoods for sale again. They tend to be the very expensive high-end ones that are doing more sophisticated sensing, so it's not just temperature, they're sensing other things as well, so that they will automatically come on when you're cooking and also change the airflow and the fan speed depending on things like what are they sensing? Right, and they can sense. There's a range of stuff and each manufacturer has their own way of doing it. That's kind of proprietary, to be honest, but you know, we know enough to. There is almost certainly some sort of temperature sensor, potentially an infrared sensor for sensing heat, possibly a particle sensor and possibly a humidity sensor.

Simon: 1:01:41

Those are the sort of things, yeah I think I saw one I think I saw one with what looked like or, like you say, it's pretty proprietary so they're not giving much away but it looked like some form of voc sensor, possibly trying that's. That's yeah. Now I'm not quite sure what the performance of those are going to be in such extreme environments. You know particulate sensors and metal oxide sensors and things are going to come under a lot of pressure. But then you know it's got to be better than nothing.

Iain: 1:02:11

Um, but I think the point is that those things are coming, automation is coming, but you know we should only the automation has to be acceptable to the people in the space, right? So you should only do this with hoods that are going to be quiet when they operate automatically. Now we've tested some of these devices in in our, in our test labs, lbnl, and you know in our test they work just fine. Honestly, they seem to do what you would expect them to do and of course it gives you the opportunity to do some extra programming. I'll'll give you an example, which is that we found that if you leave the fan running just on low speed for a few minutes after you've stopped cooking, so you've stopped emitting, you've stopped cooking you can turn it down to low speed so it's quiet.

Iain: 1:03:08

I keep venting the kitchen for three more minutes after you finish cooking. That can have quite, you know, for relatively little sort of energy expenditure of running the fan, sort of thing that can really help to reduce the remaining contaminants in the space, because you just keep venting the kitchen with a little bit of you might call it fan overrun or whatever terminology you want to use. It says oh, we can have, once you're getting smart once you're putting something smart in the hood, so it's not just a switch. Once you're sensing things and have timers and so on, you can do smart things like that about your ventilation and say oh, we know that if we leave the fan running for, say, an extra 10 or 20 minutes, it has this advantage. So we can build that into the programming so that you, the occupant, you have to think about it. The hood was just going to do it for you. You have these opportunities to be smarter about ventilating your kitchen.

Simon: 1:04:02

Yeah, once you've got some smarts in the hood. There was a question I wanted to ask you actually, um, because it's something that's come up in a couple of conversations I've had recently, actually one of them with um somebody you know well, marie coggins. She's also on the nivc with us and she's been looking at research on retrofitting at homes and and she's been seeing a lot of kitchen pollution egress out of kitchens into the rest of the house and it's raising the question do we have the background ventilation rates high enough in kitchen zones? But traditionally we've tended to have more in the bathroom zones because they've presented a moisture challenge typically. But she gets the sense and it seems fairly logical to me that we're getting maybe quite a bit of escape of pollutants into the rest of the property and then they're hanging around for a longer time because we're not ventilating well enough those kitchen spaces, because residential ventilation is much lower than non-residential spaces typically.

Simon: 1:05:10

So maybe there's an argument to improve that. But maybe it goes to your point that maybe we can be a bit more intelligent. That there are overruns, a bit like we had with intermittent fans in bathrooms in the past, is that you have when they're on, when you finish using that space. There's a period of time where let's face it, even at half the flow rate, at 25, 30 liters a second, for another 15, 20 minutes, that's going to make a big difference to the amount of pollutants that are going to be available to escape yeah, um, I think the the world of ventilation, um, it's sort of just taking its first steps to being smarter about how we ventilate.

Iain: 1:05:55

We, we, we've got smart and a lot of other devices. I mean, I think we're familiar with things like computers and televisions and all the devices you connect to a television, and game consoles, all those things. They know when you haven't done something for 10 or 15 minutes, right, and they turn themselves off or whatever they go into low power mode. We've seen that in every household appliance, but not in your ventilation system, right. And I think we're just starting down this step of being smarter about ventilation, as you say, and including things like well, let's ventilate at a slightly higher rate because we detected these contaminants, or keep the fans running in bathrooms. I mean, the bathroom is just a simple timer, right, and sometimes they have a humidistat in there that's ventilating based on humidity, but just sort of basic stuff like that. We're just starting in the world of ventilation, air quality, to try and be smarter about what we do. So there's a lot of potential there, right. There's a lot of potential there, right.

Simon: 1:06:53

there's a lot of potential to to do things in a in a in a better way, I think relatively, relatively reliably and inexpensively and I want to come back to that with you, ian, because I know it's something that you've spent in fact, it's what I've known you for for nearly a decade now is that looking at where the state of the art of sensors and our ability to measure this? I definitely want to come back to that. But before we finish off the cooking conversation because, um, we've kind of jumped onto it but we've really gone down that rabbit hole and I think it's great, um, the knowing what know, having probably researched this as much as anybody, what are the basics people should be looking for with cookerhoods? What makes good cooking exhausting versus bad and I'm assuming there are outliers like those fancy ones that pop up from the back of a cooker and magically pull the air downwards must be fantastic and magic, yeah right so I'm sure you've measured those.

Simon: 1:08:04

But, like so, if I'm out looking for a cooker hood tomorrow, what are the kind of things that you've seen work and where do you see a fall off in performance? Then after that, if you were going out looking tomorrow, what are the kind of cooker hoods that you'd be looking for?

Iain: 1:08:22

right. So you've already raised the classic problem of where should you be sucking the air from? Right, the answer is from the top of the cooking, because if you look at the plume of contaminants they go up Right. So if you have the terminology uses a downdraft system, and sometimes it's just a vent, sometimes there's a little thing that pops up with vents and they have a very hard time because what they've got to do is they've got to take that plume of contaminants, turn it around and suck it back down again, and all the tests we do show that's not particularly effective. I mean, you're still ventilating the kitchen, right. You're still exhausting you know a hundred liters per second or whatever the airflow is from the kitchen. So it's something of zero effect. It's just their efficiency is poor, right? If you had that same fan and just had it mounted in a wall or window or exhausted again, you'd ventilate the kitchen and it would have some effect. It's just not an efficient way to do it. You have to move a lot more air to get to the same contaminant concentration, so it's much better to have something over the top of the cooking.

Iain: 1:09:40

I mentioned earlier this issue of often you want to cook at the front of your device, whatever it is, whether it's cooked up or arranged in the US, whatever it is. To effectively capture that you do need something that comes up far enough from the wall or, if it's in an Island, is physically large enough that it covers that area. The better you cover the area, the better. And absolutely there are trade-offs there. I mentioned the one earlier about. Then you might be bumping your head in all the times. You have to mount it a little higher.

Iain: 1:10:11

But okay, so there's some compromises, but that's figureoutable. So physically large is sort of one idea. Another one has to do with there's the potential for other what I would call geometry-related things to make a difference. And here it gets a little more complicated and harder for a sort of an individual person who's shopping to make these decisions, because you have to know a little bit more about the product. Look, sort of look up from the, from where would, if your head was on the cooktop? If you look straight up, what do you see? All right, and if you see, like a little metal grill that's only a few centimeters by a few centimeters square, with some metal mesh in it, um, and it's stuck right in the middle or sometimes they're off center those are not going to be great at capturing the contaminants from all four hot plates or six hot plates, whatever it is you've got.

Iain: 1:11:08

They're just not going to be very effective. But if you have a big open area and it's over the whole area, they're going to work a lot better. So there's there's some like critical geometry things. Um, after that there's some oddities that I think are less prevalent in europe, but we see a lot in the us, which is we put our microwaves above our sartorius, uh, was talking about this on the podcast the other day and I had no idea.

Simon: 1:11:36

But now I think of american television and, yes, you see it all the time. And that's this. This thing about microwaves above a cooker yeah, that's a thing so we're like.

Iain: 1:11:49

So that happens all the time, and the question is is that an effective hood? And the answer is sometimes yes and sometimes no. We've tested ones which were just terrible and others which worked out okay, but unfortunately we don't have a rating system in place yet for you to know that. This idea you said if there was a good label, you could pick the microwave that was better than the other one, right, once we've got a good label. You can't do that right now, but I think you will be able to in a year or so. So, and microwaves have this complication of they not only have vents in the bottom, but they also will have vents in the top, like along the top of the door and other interesting things, and they have a very different airflow pattern that they set up, and so it gets a little trickier to measure them right because they're not, they're not the other things, and.

Iain: 1:12:39

But we've had very mixed results for microwave hoods. Uh, like I said, some some really didn't work well, uh, and and some did, and it really depended on things, I think, like where are the holes in this box, right? Where's the air getting sucked in? And how effective is the fan? Yeah, right and a whole bunch of other things, and I think that one of the critical things for the, for the range hood models we see in the us is um, they struggle with the noise issue because you can imagine the passages that the air has to go through. They're pretty small because they've got to wrap around a micro this is still the microwave oven is still in there. Right, they're going to wrap around it. They're small, they get noisy, so they have noise challenges as much as anything else, right, um?

Simon: 1:13:25

yeah so, but and to these things, to these things fundamentally affect how effective the flow rate ultimately is the? Is the flow rate pretty arbitrary because the other confounding factors make such a big difference? Or have you seen kind of volumes of airflow that just make a fundamental difference, so that you were kind of mentioning 50 liters a second or 100 cubic feet a minute or whatever? I can't remember what you said, but is there some kind of volume thresholds that you see? Yes, you start to see a reasonable difference here.

Iain: 1:14:05

Absolutely so. At the minimum air flows we use in the US, which is 100 cubic feet per minute or 50 liters a second, there can be a really big variation in efficiency. Could be as low as like 20% or less, but maybe it's over 70% depending on the device that you're looking at. So a huge range to low air flows. But once you're above, once you get to higher air flows by higher air flows I mean greater than 300 cubic feet per minute or about 150 liters a second Above that, the differences get much, much smaller, mostly because at very high air flow rates just about anything is going to be good at capturing that plume and throwing it outside.

Iain: 1:14:58

Because what you're changing effectively with the volumetric airflow rate is you're changing the mean air velocity in the air entering underneath the hood, and this is an air velocity slash momentum thing. We're not going to get deep into the physics or the science of it here, I promise, but there's a momentum in the plume. Right, it's hot air and we know roughly what velocity it moves on its momentum. If that momentum is bigger than the velocities and momentum associated with the air entering from the kitchen, then the plume can escape. If it's lower, it's less likely to escape, and what happens is a high airflow.

Simon: 1:15:42

I think people can imagine you take a lid off a big boiling pot. You see that plume of steam coming up, we've all seen these plumes, big curtains of it plume outside of the cookahood if it's not exhausting fast enough, but if it's. If it is, it will suck it up.

Iain: 1:15:57

You know you get a totally different shape of plume if it's working effectively if you're boiling a pot of water, you can do your own fluid mechanics experiments in your kitchen any old time by you know. Stand to one side and see how well it's captured, and turn up to high speed and see a change. You can all do it, it's relatively easy. But the point being that the high, high air flows you've induced such high velocities in the kitchen towards the cooktop that you can basically overcome the plume and you'll have very high capture efficiency and it won't matter so much the specific geometry of the hood anymore. When you're at very high air flows you get over something like 85 or 90 percent capture efficiency, no matter what. But the reason we don't see that done very often is that's when it's super noisy. Right, that's moving a lot. But the point, to answer your question, the variability is in the airflow range which is below that for quiet operation, which is what people want to use, and rightly so, and we're trying to set minimum standards for that, for those air flows that are generally lower, you know, particularly down at mandated minimums. That's where we want to set. We want to say a minimum of 100 CFM, but you must also have, let's say, 75% capture efficiency at that lower airflow, because we could do something that wouldn't really change anything. We could say well, you've got to be above 80% capture efficiency at the highest airflow possible. Almost all the HUDs will do that.

Iain: 1:17:38

There is an exception to that and again, simon, you're already telling everybody everything I know, which is that there are different grades of hoods. There are high-end, expensive hoods and then in the US we call them builder grade. This is the least cost product, right, that is built down to a price. It has the cheapest switches in it. The blower motor is the cheapest, the fan blades are the cheapest, everything is the cheapest. We call it builder grade because that's what everybody wants to put in in new builds. When you buy them in bulk, they are very inexpensive. When you're buying thousands of them and they're built down to a price point, those tend to not be able to reach high air flows.

Iain: 1:18:23

Frankly, Well, quite frankly, they don't even hit your minimums Right, they don't have a good blower in them and the other thing that challenges them is that they are often rated basically with no ducts attached. But in any real kitchen I guess the exception would be if you go straight out through the wall. So the length of duct is a few centimeters, okay, but we've often found in kitchens that is not the case. Often kitchen vents go, say, vertically up from the kitchen and up to a roof vent, or they go up for a bit and then they go out to an eave vent and they can have several meters of ducts with elbows attached to them and there's definitely going to be a rain hood on the outside. All that stuff is airflow resistance and if you've got a good blower, it's like I can still move the airflow required. But if you have an inexpensive blower it will not do that.

Iain: 1:19:29

And you alluded to this, which is that we've certainly done plenty of measurements in people's homes where the actual measured flow is nowhere near the rated flow. And it's because you have to account for this airflow resistance. And you know there are some other things like over time you get grease buildup and things like that and dust inside the hood mechanicals right on the blower wheel in the motor and those all conspire to reduce air flows as well. But that tends to be a gradual thing. Over many, many years You'll definitely see it degrade in performance. But I'm talking here about when the device is brand new. It just got installed into the house, it got connected to five meters of ducting for elbows and you turn it on and you don't get the airflow. It says on the box.

Simon: 1:20:23

It's much too close right, because because the pressure, the pressure drop on crappy flexible ducting or cheap ass plastic ducting with crappy or cheap-ass plastic ducting with crappy outlets, even at 30 litres a second, the pressure drops down. That stuff is so horrendous that the fans that are trying to overcome that just don't stand a chance, and the bad news for my UK listeners is the average airflow that I've measured on kitchen hoods in the time that I've been doing it over the last few decades is well below 15 litres a second.

Iain: 1:21:00

Yeah, that's not effective in ventilation?

Simon: 1:21:03

No, not even close. Yeah, and that's what we're facing. Is that builder grade, what's the cheapest possible solution? Because what goes with that then is a cheap installation and lack of thought, thoughts and design and so on, and you get a very, very poor outcome.

Simon: 1:21:22

Um, so, for context, for everybody, the vast vast majority of you, um, unless you happen to have built your own home or put a decent range hood in or something like that, for the vast majority of people their cooker hoods are not going to be doing what we want cooker hoods to be doing, and that's a challenge. But I think labels and some kind of standardization of that will have a very big impact, because at least that's the starting point and it and it frames a value that we've not had before, because, genuinely, if consumers aren't asking, oh, what's the performance of that cooker hood? When they're going around and visiting homes, they're going to buy. Nothing is ever going to change, and that's the challenge. Or when they're going in to buy a new cooker or replace a cooker and a cooker hood, that eventually there's some minimum standards that these things will have to achieve and with that will come guidance of installations and so on.

Iain: 1:22:26

Yeah, in the US we're working on the minimum standards, part of it and partly to recognize the issue you and I've just talked about, which is we have to understand how these things are installed right. And so, uh, again, we're working with manufacturers and rating agencies to actually rate at a different uh rating point. So, instead of rating effectively at no airflow resistance, which has kind of been the industry standard that's not going to happen in the future we're going to rate with a. It's effectively a fixed airflow resistance. It's supposed to represent, you know, several meters of ducting and I think it's two elbows and an outlet. It's a standardized thing that we've basically all agreed. This is how we want to rate things. Again, your mileage may vary in your kitchen, right, if you have longer or shorter ducts. Obviously that's still true. But we want to take that first step from what is frankly a very unrealistic rating point, which is effectively no air flow resistance, to something which is like oh okay, you might see this in a lot of kitchens. It's much, much more representative of the real world performance. What it's gonna do is, you know, it's a minimum standard thing. It sort of puts a performance flaw. So the very worst devices, they will not be able to get rated, or rather, they won't move in a flow that they will be able to say we meet the minimum airflow requirements at this new testing point.

Iain: 1:24:07

Yeah, and the terminology that we're going to use in the US is something called nominally installed airflow NIA, so that, in other words, we're changing the rating procedure to try and better match what we think happens in actual kitchens. Yeah, it's going to take a while, but we are definitely trying to change that. And you know, if only this was international, it's going to happen all over the world, and you know, but it's. It's not right. This is a regulatory change and a ratings change, and it's going to go country by country is my guess, but I think somebody has to do it first. With a lot of these things. If one country decides to do it, manufacturers selling that country now have to rate under that method and it becomes much easier for the next country or the next rating organization to say oh, we want to account for that as well in our ratings and so now we're going to do it. So hopefully to help your UK listeners, simon, what you've done in the US, the UK can then go oh, we think we should rate this way too.

Iain: 1:25:17

And particularly as if key manufacturers have already changed how they rate, then you need the manufacturers on board with these rating changes, otherwise it just decays into years of back and forth over how you're going to have regulation changes. And the way to do regulation changes in an expeditious manner is to get everyone on board first, and I think we're kind of doing that already. Yeah, but pretty soon in the us that's going to be the standard is. Uh, you'll have to have a pretty good blower in your in your kitchen ventilation system for for it to actually perform at the minimum level that we're going to require and I know it's quite state by state in north america, particularly when it comes down to the regulation or the standards on the ground.

Simon: 1:26:08

Where are things generally with that kind of independent inspection of standalone ventilation systems is the standards of defining how a product performs, but also then standards around checking the installed performance of ventilation, kitchen cook hoods being one part of it.

Simon: 1:26:32

But that, for me, is the other area. I think where we can start to capture this a little bit better is actually measuring the performance, and I know cook hoods can be much more challenging to measure, especially if you don't have access to the terminal on the outside. Measuring the actual cook hood can be near on impossible. But that's enough because, like I said, you know I can count on one hand the amount of time in 20 years I've seen a cook hood actually do what it's supposed to. Um, and that's the other way of correcting this situation is that if people start seeing poor performance measured performance you can start holding people to account and say hang on, a minute, that's supposed to be doing 50 liters a second, it's only doing 20, fix it in in, indeed the, but the, as you say, the challenge for kitchen ventilation equipment is actually doing the measurement.

Iain: 1:27:30

It's, it's, it can be easy, but often it isn't. Yeah, right, as you say, if you don't have access to the term, the exhaust terminal on the outside of the building, it's hard, right, which is why we're going down this changing the ratings route. Yeah, to sort of bypass that, that is, if, if you change the rating, so it's challenging enough that you have a you cannot reasonably believe you'll get the right airflow when it's installed. Um, we believe that's probably the easier way to go, because it is just so hard to measure exhaust air flows from cookahoods. It's easier in bathrooms, for example.

Iain: 1:28:10

Bathroom fans are quite easy to measure. There you can go and get very relatively simple airflow measurement devices and and do that. But it's just all the range of geometries and and actually getting something between the bottom of the cooker hood and the cooktop. And I mean, frankly, you know the, the high-end research we do at lawrence berkeley national laboratories. We take lots of cardboard boxes with us. We go to people's homes and we literally custom fabricate out of cardboard and tape, you know, capture boxes that we then pressure, equalize, fan to, but you can't do that on a production basis, right? I mean you can quote, unquote, get the right number that way, but no, that's not something you can do on a production basis. Only researchers will ever do it and should ever do it.

Iain: 1:29:03

Frankly, I mean you could make the argument, though, that there should be some sort of built-in airflow device, I'm sort of going back to can we be smarter about indoor air quality and ventilation?

Simon: 1:29:18

Well, you know so much of our.

Iain: 1:29:20

Why should there be an airflow system? Yeah well, so much of the ventilation.

Simon: 1:29:22

Yeah well so much of the vet sorry, yeah, no, no worries so so much of our of the ventilation technology we're seeing in homes now are constant volume fans. You know they have their own calculation methodology in there. They know how fast they have to go at certain pressures to deliver certain volumes. So you set, you set the fan to do 15, 20, 30, 60 liters a second and it will spin as fast as it has to to achieve that, knowing the pressure drops and things that it's facing. Either that or you provide uh ports in the ducting or in parts of the machine to be able to take a reading, you know, at a known diameter of ducting or something you know, that there's a million ways this could be done practically if it was important enough to do.

Simon: 1:30:09

You know, if you made it a requirement, it has to be a priority right and at least in in the us.

Iain: 1:30:18

I'm talking here not just new construction, but if you're doing a major remodel of a kitchen or a home, the priority for most building code inspectors are life safety things like have you used the right wires when you wired up the home? And structural things like have you used the right either dimensional lumber or, if you're doing masonry construction, have you used the right metal reinforcement rods? You know the roof won't fall. Those are sort of like construction safety things. Some things we're talking about are kind of new and, frankly, still low priority. Even after all these years of working on air, of having air, air quality and ventilation standards in buildings, they're still kind of new.

Iain: 1:31:08

So we have to make it easy, as my view, and I think these some of the ideas you've talked about. You know there should be a push to test button for any building inspector or installers, even like the, you know the electricians or whoever's installing should be. Should we push the test? Green light, red light, tells you if it's working or not. We need to make it easy to determine this and not require you to fabricate your own flow cap your head out of cardboard, because that's nonsense. Right, it needs to be easy, because if it's not easy, it won't get inspected and no one will ever care, right?

Iain: 1:31:45

Um, the only time people will care is, you know, if it becomes a significant thing, and and I mentioned this earlier in our in the podcast, simon is that when we have surveyed people to ask them how often do you use a kitchen ventilation or cooker hood, and if you don't use it, why not? The common answer is it's not needed Now. So when people say that if they're frying something and there's lots of smoke or something, they will definitely turn the hood on those are our observations is when there's obviously something where you're like oh, we better vent this right now, because the house is filling with smoke and the smoke alarms have just gone off, then the cookahood gets turned on Right. When it's seen as when there's something obvious saying we'd better vent this, but most of the time, no, because we're like what is the problem here? There's no. You know, people have been cooking for centuries and people didn't drop down there to whatever you know, whatever story people tell themselves, because that's that's how people make decisions.

Simon: 1:32:49

is the stories they tell themselves Full circle back to risk communication, isn't it really? It's a it's that you know. I don't perceive a problem, therefore, why would I turn it on?

Simon: 1:33:03

Before I forget it was one of the things I said I definitely come to you on um was we can see the air better than we ever have been able to more affordably than we ever have to have been able to, and that's changing the narrative ever so slightly, and potentially quite fundamentally, and that it becomes much less about whether your product was compliant during manufacturing or your home was up to code. Objectively, you're going to be measuring the performance of your building on an ongoing basis, and one of the things you might be measuring as we go forward is air quality. Um, so does it matter how good your cooker hood is? If you don't produce the pollutants that are of concern, then do you care? Or if you've got a decent cooker hood but you you do so much cooking that you're just exposed chronically to higher levels of pollutants from cooking, then that might be more of a problem to you than for somebody. That doesn't we.

Simon: 1:34:05

When you start measuring outcomes, air quality outcomes, it changes the narrative. You know we're struggling here to get people to deliver a rollic performance, air movement performance, which is like the fundamentals, and I have this argument the whole time that how do we, how do we think we're going to cope with trying to adjust for air quality outcomes when we haven't been able to deliver air movement performance outcomes today? Objectively, we've failed to do that pretty much in the built environment, but we are starting genuinely to move into this era now where somebody's going to see that they're getting a lot of particulate matter spikes in the living room every time that they cook. That's a different narrative, isn't it? When you start looking at air quality outcomes as opposed to air movement outcomes yeah, I, I, I think so.

Iain: 1:35:04

I mean, there's a lot to unravel here. But the, the advent of relatively low cost, what I would call consumer grade air monitors um, that are, you know, you just go buy one, right. Right, it's not, it's relatively trivial. They're not, they're not free, but they're not super expensive. You know, the, the laboratory grade particle sensors we use are like 70,000 euros. No one's going to have that in the house. But what if you can get something for a couple of hundred euros right With a nice little display on it, which is what you're talking about, I think. And actually, the advent of pretty the particle sensors, I think, were the thing that really pushed this, and here's why they, these optical particle sensors, got produced in a way that they became much more reliable and lower cost and now you could conceivably put one in a little box in the house.

Iain: 1:36:03

Before that we did, we did temperature and humidity. Right was sort of what we classically measured in homes. Temperature. You know, we've used temperature as to control things in our house forever. People have had thermostats in homes for more than 100 years, right? Um, humidity, we talked about ventilating bathrooms, for example. Ventilating bathrooms, for example, ventilating your bathroom on a humidity control has been around for decades, but once we could measure particles, we could say something much more definitive about the health aspect of air quality. I think that's the important thing it brought in this health idea, because particles are the number one thing in terms of health impacts. Now we could measure it relatively inexpensively. You could put all these in a box and sell it and people, as you said, can watch what happens in real time in their homes to particle counts. Often these devices sense other things. Your listeners are probably familiar with TVOC volatile organic compounds, right? I'm not convinced that's a great measurement for a host of reasons. We can talk about that later.

Simon: 1:37:11

That's a whole podcast in and of itself, ian. I think the value of TVOC monitoring.

Iain: 1:37:19

But being able to do particles and sometimes CO2. Again, we have to be careful with CO2 because not all of those consumer-grade devices are actually measuring CO2. Sometimes it's inferred and the ones that infer it are worse than useless they're. Usually they don't even get the direction right. It's not even worth doing. But some, if you read the fine print you have to read the fine print that has a real CO2 sensor in it. It tells you something about the general ventilation rate. That's good for perceived air quality sort of thing, right for general ventilation. But I think it was the measurement of particles really was a game changer there. Right, because particles are used in ambient air quality indices that, at least in the US, have been around for quite a long time. Your daily weather report on the television, for example, would have a little box in one corner that had something called the AQI, the air quality index, telling you mostly about it's mostly particles, but some other things in there too, and there's a network of sensors all over the US and I'm pretty sure you have these in Europe and probably other parts of the world too, for ambient, for outdoor air quality. So this concept has been around for a while. People have seen it on newscasts, and sensitive populations have been tracking this for a long time, at least from the outdoor air quality point of view. What these devices have allowed people to do is to now do it indoors, and I think that the early adopters were mostly from what I would call sensitive populations, so not average people, but people whose health really does depend on air quality. Asthmatics are the classic subset of people who are sensitive to air quality, but there are also the elderly and young. Children certainly have increased sensitivity to contaminants and pollutants in the air and I think that there's been some pretty widespread adoption by that sort of subset of people. Then there are people who are just generally more concerned about their health, like out of the, you know, out of the population. There's a fraction of people who are very concerned, like they saw this device let's get one and see what's happening in our home, right, but I would call those people the early adopters. The question is, is it ever going to be that every home has this? And this is just my opinion, based on nothing, but my opinion and experience of this trying to do things in people's homes and meeting a lot of people and talk about air quality is that I think that for most people they just want healthy air and they don't care how they get it. It goes back to our conversation earlier about people want a warm, comfortable home. They don't care how they get it right, they just want it to work, have it automated so they don't have to be air quality experts and do it themselves. I think at the mass market scale that we have to automate it. But what helps you get there is you have to have early adopters do early adoption. What the early adopters are doing in this case I mean early people are early adopters about being concerned about indoor air quality. They're using these monitoring devices. It's a game changer in that sense. It's really raising awareness.

Iain: 1:40:37

And I think two other things have really changed in recent years. One thing in North America, and some other parts of the world too, has been much, much worse wildfires than we've known historically for quite some time, which would result in very, very bad outdoor air quality and also poor indoor air quality, lots and lots of health impacts, hundreds of millions of people affected. So wide scale disruption, just easy Our air quality challenges. Generally you can't see it, but with wildfires you can, and that was a huge trigger for people to think, oh, should I be breathing that air and what's in that air that's dangerous? Why would I not want to breathe it? Should I be monitoring this in my home? This, certainly in the bits of the US that got wildfires, which is now most of the US and Canada and Mexico also huge awareness raising.

Iain: 1:41:35

Then something else came along, which was COVID-19. And that was another sort of escalation of people thinking about air quality. In this case it wasn't particles per se or some of the other volatiles that are in smoke. It was this idea that you could be infected with an airborne virus, right, and people started thinking about should I be wearing a mask? Should I be filtering the air? Should I be ventilating? All these questions about that are all air quality questions effectively, and those two things have again, really, I think, changed people's thoughts about this.

Iain: 1:42:18

But I think in general people didn't think about air quality very much. But now they they do. And when I say people talk about talking about generally overpopulation, who would care? I think the awareness has gone up a lot. And what I think we need we being the indoor air quality industry to respond to that, we need good answers to people's questions. We need to be able to say oh well, we've got these automated sensor-based devices that will control your ventilation systems and maybe shut it off automatically if there's a wildfire or maybe increase it more. If there's a button you can push, which is the I want more airflow button or I want to turn on some filter button, maybe that could be automated. But you should give people these options because now they want to use them. People have awareness. They're like well, maybe I should be cleaning my air or ventilating more or ventilating less during a wildfire event, in fact.

Iain: 1:43:18

But from a residential perspective, it's less so for commercial and large buildings. From a residential perspective, it's less so for commercial and large buildings. From a residential perspective, the industry is not there. The buildings industry has not really responded to that that I see in any significant way, and maybe they should. But, as you say, unless people demand it builders and contractors it's a hard sell for them. They're going to sell to the early adopters and have done right. That's happening. But for it to be every home, I think it's going to be this balance of increased sort of general public awareness and the availability of things that make it simple, easy and automatic. I think those two things need to happen in concert. I'm not so sure the second of those things is happening, but it's possible, right?

Simon: 1:44:05

I think we have enough confidence in our sensors to to do, to automate some of this anyway yeah, we're getting, we're getting close, yeah, and it's been interesting to see your research over the years how, how the view of these low-cost sensors has changed and where we seem to hit thresholds where all of a sudden there's a an underlying confidence in a way of measuring a certain parameter. We saw it with ndir sensors, we saw it with optical particle counters for pm. Right, and what's interesting and to add to your point about you know, pm is a specific pollutant of interest, whereas co2 has always been a bit of a proxy. Tvocs are a proxy, you know temperature and humidity or a thermal comfort proxy. You know they will have an impact down the road on condensation, damp and mold, but they've all been kind of kind of proxy based, whereas pm was really the first sensor.

Simon: 1:45:00

I think we've got confidence in broadly, confidence in the, what we're seeing and it actually has a direct health outcome, really zeroing in on some of the pollutants of interest like ozones and formaldehydes and noxes and how they develop over the next few years. You know, and you know I'm talking to a number of sensor manufacturers who have increasing confidence. They're getting more and more bullish about the confidence they have in their sensors. They're not perfect but they're getting better and it'll be interesting to see as we build up that picture how things change.

Iain: 1:45:50

Yeah, I think we're going to need some sort of standardized rating way to approach that. We talked about this for cooker herds, right. That we talked about this for cooker herds right. But I think we're going to need there needs to be some sort of tests that we run these devices through to see you know how good are they really. Because we do see people making a lot of claims and I can tell you from some careful laboratory studies that those claims are not always true. But how do you communicate that on a consumer level, right? There aren't necessarily rating agencies for tvoc sensors. Yeah, right, that's not a not a thing. And we might, we might need to have that, I I feel, because I think it's relatively easy for people to manufacture a device and claim it does lots and lots of things. But does it really Right?

Iain: 1:46:50

It's not always obvious and there have been efforts to provide sort of public information on this, but they're not organized in any realistic way. I mean, they're just oddities. Like in Southern California, the Air Quality Management District there has tested lots and lots of air quality sensors, multiple units, to look to see if you buy multiple units, are they all the same and from many, many manufacturers, but that's sort of buried in an obscure part of the internet. No one would ever go looking right, it's experts only. Really that's not useful from a consumer perspective. So some of this testing has happened, but it hasn't happened in a way that's visible to consumers. It's only for particles. Really, to be honest, the other things haven't been done so well and until we get out of that I don't see how we're going to be able to give consumer confidence in these devices.

Iain: 1:47:53

And you mentioned earlier that maybe we need to get away from possibly saying it's an airflow issue and just control for contaminants. That could happen. You could use these to control. I'll call it an air quality system rather than a ventilation system, because I do want to include things like air cleaning devices. You know, the classic air cleaning device is, uh, you know, a standalone air filter that many, many people install in their homes during the wildfires and in north america and you know what they they, they really do work job yeah, right, they have a good filter.

Iain: 1:48:29

They really they really cut out that pm 2.5, which is the critical thing, um, but that's, you know, that's of a consumer. Again, it's a consumer device that that works well. It's not automated or integrated into a building in any in any way. Right, you, the consumer, have to go out and purchase it, put it in the room you want to clean, turn it on and off. I mean, they have some automation built in, right? I mean the one I have at my house and many others do this. They have some sensors in them and they will do things like they will change the fan speed and increase the fan speed if they think that the contaminant levels have gone up. It isn't clear exactly what they're sensing, right, and again, it's like the coco heads earlier. There's a lot of proprietary things going on where you could saw one of these things in half and find out, you know, is it actually a via little voc sensor? Is it a little particle sensor?

Simon: 1:49:26

you could do that, but it's kind of proprietary yeah, well, I think I think once it matters enough, somebody pops up on youtube that does the cutting them in half youtube videos and seeing what's in them I believe the information is available.

Simon: 1:49:41

Yes, you know um, you know and I've had interesting conversations with house builders that, along the same lines as car manufacturers, that there's different levels of presentation of this information. You know data's got to be actionable, otherwise there's no point having the data. So it's fine to say you've got high, particular levels in your living room, but if you can't do anything about it it becomes useless after a while, right? So there's got to be that agency and actionability out of data, and we're seeing that very much so with the internet of things and data being productized and solutions being provided and sold to people that the stickiness of those solutions are very much based on. Does it actually improve outcomes for me? So I think that's encouraging to see markets developing that, and we see that in social housing a lot. You know low cost sensors connected to platforms providing very useful useful information to drive better outcomes.

Simon: 1:50:44

But below that and the conversations I've had with house builders have been a bit like with your car. When you take your car in for a service now, the technician plugs it in to see how you've been driving it, what the oil viscosity is, what the level of the brakes are. You know all of that information is available to him at a service level. To you, that information is presented with a couple of red lights that blink on and off on your dashboard. But below that is a layer of data that's available for the technical people that are involved in that product to deliver a better service and a layer below that. Again, that data goes back to the manufacturer to help them improve safety and warranty on products and longevity and robustness of the things that they build. Yet our car isn't even close to the largest purchase we make in our lives and we don't have any of that data coming out at that level out of the built environment. And the conversation I've been having with house builders is you're having to make and it goes back to the beginning of our conversation increasingly more complex and nuanced discussions on the type of products that you use and the types of services that you put into houses and how people are going to use them, how people are going to use them. And data has to become part of that picture for you, because you can't manage what you don't measure. You can't improve your product and streamline it if you don't have that feedback loop, and the built environment seems to be one of these industries that just hasn't caught on to that. You know that we're not making decisions on how we build our buildings based on data. We almost it's almost completely on slow historical progress and anecdotal feedback is the way that buildings get built and improved over time. So, like we're getting close, I think it won't be long before your service technician plugs his laptop or connects his device to your home to see why the boiler's playing up. And it won't be long before the house builders are slowly improving those products, because the data they're getting back from the heat pumps and the thermostats and all the devices that are collecting this environmental data are providing a picture that enables them to make more nuanced decisions and A and B profile solutions and how you communicate stuff.

Simon: 1:53:08

Because, as one developer told me, if you build a thousand homes, you can guarantee that at least a dozen people that move into those homes will move in with sensors and they become very whatsapp group people quite quickly on your estate saying you sold me an a-rated home and here's the data to say it isn't. You know, and we're seeing that in the workplace environment as well. You know you have a thousand employees. You can guarantee a number of them have got air quality sensors on their desks now at this stage. So it's coming whether you like it or not. The choice is do you get on the front foot and get ahead of it or do you have a reactive business the whole time and have to deal increasingly with people ringing you up and going? The air quality in this new home you sold me is rubbish. What are you going to do about it?

Iain: 1:54:02

yep, uh, indeed, I mean, sadly, I think I think the picture you paint is correct and the the risk, the the risk and cost analysis for larger corporations anyway will be um, so we get some lawsuits and we get sued, but maybe we'll just pay those lawsuits because it's cheaper than changing our business practice. I mean, I don't want to be like too cutthroat about it, but that's literally. You know, the history of manufacturing is riddled with these sort of things. People like, yeah, the product's not 100 safe, but we'll, we'll pay off, we. We think there's going to be 100 lawsuits, at least, you know, 10 million euros. We'll pay that off. That's cheaper than us actually fixing the product. I won't mention any names, but Ford Pinto, right, that was the classic thing in the US. Right, they knew there was this design fault, but they figured it was cheaper to pay the lawsuits. Now, that's a very cynical approach, right, and I don't advocate that approach at all. But I'm just thinking to fundamentally change large corporations. That's how they think.

Iain: 1:55:12

But I think that the building industry, it's really kind of quirky, right. I mean, to some extent it still hasn't had the industrial revolution and to some extent it still hasn't had the industrial revolution, particularly in the US, we are cutting bits of wood to length on site and hammering in nails. So it's, nothing has changed right. There is no industrialization of it whatsoever. Now you could say to me, oh yeah, but there are some factories making houses and panels that are assembled on site, and I would say, yeah, but that's such a tiny, tiny fraction of construction. And for building renovation, almost none of that, although again, there are some like little baby steps being made. That's tiny, so that industrialization never happened in the buildings industry, which means that they're way behind when it comes to adopting these ideas you're talking about. That are commonplace in automobiles of. There's one port. Everyone agreed what the port looked like. You plug it in tells you everything. That implies some sort of standardization and industrialization, which does not exist in the buildings industry pretty much. And again and buildings are a weird thing With an automobile, yeah, parts are pulled in from all over the world, but it's assembled in a factory under very controlled conditions somewhere, and the manufacturer of the car is in one way or another responsible for every single part of it, whether it's.

Iain: 1:56:43

You know, cars have air conditioning and heating. They don't make hot water. I mean, maybe they should if you want tea. But you know everything built into the car is the responsibility of the manufacturer. In housing we just don't have that.

Iain: 1:56:58

It's highly fragmented, right the devices that heat the home or make the hot water or whatever, it's not all brought under one roof. There isn't one person responsible for it. You call the individual companies that manufactured those things. If there's a warranty claim and all this sort of stuff. It's really really hard to pull it all together because the industry is not structured that way.

Iain: 1:57:25

So this is less of a technology problem than maybe how an industry is structured issue in terms of how do we get everything to pull together. So the manufacturers of heating and cooling systems are not the same as the manufacturers of ventilating systems, who are not the people who did the air sealing. They're all very separate, all different companies doing it right, and so there's no, there's nothing pulling everyone together so that the manufacturer heating cooling system knows that there's a actual heat recovery ventilator and say, can juice the loads, and neither of those companies manufacturing those know anything about how well air sealed the structure was that it gets. It's all getting installed it. This is all done in a very ad hoc, unplanned way, to be frank, and this is why the the, the things you're talking about, we just don't observe in the building industry, because the building industry is not there.

Simon: 1:58:21

But but interestingly, I think, where we are now with technology, particularly with connected devices, environmental sensors, internet of things, we're able to pull together strands of data from different sources relatively easily through apis and connectivity of different systems online and build a picture of performance of spaces without needing that coordination. You know we can. We can take weather data from a local weather station. We can take sophisticated temperature and humidity data from a smart thermostat. We can take electrical meter data from a smart meter, uh connected to someone's home, and we can calculate heat loss transfer coefficients in that space, because we understand time to heat and time to cool, normalized with outside temperatures, and we can see the energy input into the house. And all of a sudden we've got a live co-heating test going on in that home 24 hours a day, seven days a week, 365 days a year, with three bits of data that are online anyway.

Simon: 1:59:34

Um, and that's the power I think that's the era that we're moving into is that all of a sudden, you suddenly create a performance kpi for a building and it's not your kpi, some other flipping company is, does, does it and causes you trouble. You know that all of a sudden you can map and look across an entire district and see which homes, which brands are performing worse than others, you know, and that has an impact on the industry when all of a sudden you go. Well, you don't buy a bellway home because they're there. Their mile extra urban miles per gallon figure is lower than the wimpy home you know, and all of us.

Simon: 2:00:17

You know it doesn't doesn't take long, for some clever, annoying wallet is putting up a league table on the internet of how well, how energy performance those homes are, you know, causing unknown trouble.

Iain: 2:00:34

Right, that all sounds very interesting, but I wonder if that's, if that's uh gonna happen. So an issue we have, at least in the us, is this that you're right that if you have a smart thermostat broadcasting to the internet you can log temperatures. Not a problem, heck, if you've got three or four thermostats in your home, uh, you could do zonal temperature, you could have all that information.

Iain: 2:01:03

You could do the same with um metered fuel use, right, whether it's electricity, gas, whatever, you can certainly do that um, the the challenge is there's all this other sort of what I would call metadata that someone has to have recorded and make readily available, like okay, so I know the temperature in the house, I know it's fuel is, but how, how big, how many square meters is that home? You better know that, right, and if you're going to rate these things, you would have to know things like and, um, you know, is it, is it sheltered from wind and sun at all, this home? So I I can do an oranges to oranges comparison, because an isolated home on a hilltop isn't the same as a home in a street. Right, and particularly if you're going to put solar PV on the roof, you've got to think about what if this house just has big trees next to it. That, that, what I call the metadata, so the stuff that isn't recorded automatically, is the challenge If you want to do those sort of league table things, because otherwise you don't end up with an apple to apples comparison.

Iain: 2:02:07

That and I'm not saying anything new here right, this is something we've known for a long time about energy efficiency rating of buildings is. There's a lot of other things, and things like what if one person lives in the house or six people live in the house. It's the same house, if you want to. If you want to compare, you know how much. How much energy they're using for hot water. It's very different, right? Or the energy that they're using plug, plug and lighting, right? So these are some of the challenges and I'll and we'll end on a positive note. I'm just throwing all the negative stuff out there because this is the. This is what I have to deal with on a daily basis. I want to outline the challenges we would face to get to your idealized world In the US.

Iain: 2:02:51

Anyway, there are also quite complex legal barriers about sharing the sort of data you're describing. Like the temperatures inside someone's home that's not shareable data. Like the temperatures inside someone's home that's not shareable data. Billing data from your utilities, your power company that's not easily shareable, because we protect people's personal information. The number of people living in a home that's not shareable information. And so there are challenges there that I think they are real right. We shouldn't automatically assume that all that information about people's lives will be freely available.

Iain: 2:03:40

Obviously, you can set up a system where people would opt in right. There could be, you know, every time they get an email with the new electric bill, there's a little link that says if you want to opt into our system of whatever it is, click here so you can allow people to opt in. Right, you get their permission to share their billing data. In the US, we actually have a system called the green button. It's not literally a green button, it's a virtual green button, but you can opt in to sharing your personal data about what is your electric bill, for example, important.

Iain: 2:04:12

When we talk about these systems and I know that, particularly in Europe in some ways, europe is more sensitive, I feel, than we are in North America to these things Every website you visit that's European-based asks you a lot of questions about sharing your personal data and what cookies are being exchanged and things like that, and I think that is a significant challenge. When we talk about all this technological integration is about the legal aspects in terms of you know what is personal data and what isn't personal data, and should people have to opt in or they automatically in and have to opt out? And the lawyers for this podcast will be able to tell you the answer to that better than I can. But it's it's.

Simon: 2:05:06

It's not, yeah, it's not an insignificant issue, and my well, I mean, if you look, if you look under the sector, it's probably the most advanced in this at the moment, which would be the uk social housing sector. I would say the. So the proposition is this that a landlord is going to be putting a device in your home that is measuring things like humidity and temperature and the kind of behavior that might be causing problems with damp and mold. The refusal rate for environmental sensors going into social housing is less than 1%. There we go, so that might work out.

Simon: 2:05:52

So so my point here is is that, like a lot of personal data, I don't think people give a monkeys about personal data If it has a value to them.

Simon: 2:06:04

Giving that data away you know, the amount of information we all both give away on our mobile phones is horrendous, obviously, but we just we make a decision that the value we get from that data is worth those sacrifices If we're making a conscious decision about it. A lot of people same with the home. I, I think. If you think that these devices are going to enable you, empower you, to make better decisions about your home, then it's the kind of data that people seem to be, on the surface of it, quite willing to give up. I think, um, that the the proposition for tenants is that it enables their landlords to provide a better service that enables them to say look. I think, um, that the the proposition for tenants is that it enables their landlords to provide a better service that enables them to say, look, I've been telling you, I've got compensation, damp and bold, for two years. Look, the data tells you. So you know well.

Iain: 2:06:52

Yes, people might not like the answers to those questions. Right is the thing.

Iain: 2:06:57

And to be clear I I think you're right that many individual people, if you ask, ask them. If you ask them, do you want to opt in? They will. The issues are ones raised by lawyers who say to people like me as a researcher, they're like oh, you simply can't include those things in your R&D because legally we think there we might get sued and we're worried about getting sued. So we don't want you to do it, so it's, it's my. The feedback I'm getting is not that individuals might not want to be involved. There may be some that won't, but it, the lawyers won't allow me or major corporations to do it because they're worried. Yeah, it's a risk for them. They're worried about getting sued. That's the, that's the, the road, if you will, to enabling that sort of thing. It's a legal profession, not an individual's choice.

Simon: 2:07:52

Well, it's going to be fascinating to see how that develops over time. As I suspected, ian, I only got about about quarter of the way down the questions I plan to ask, as is all all of our conversations we can meet again, obviously, in the future.

Iain: 2:08:09

There's still lots to talk about we. There's so many things about air quality. We didn't, we didn't get to and and yeah well, we'll just we'll talk next time about this sort of strong link that we think there is between changing the fuel infrastructure whether that's vehicles or homes probably both, because they're connected these days and air quality and health. We didn't quite get to that, but let's do that later.

Simon: 2:08:35

Yeah, for listeners this is indicative of me and Ian's conversation over the years. Is we sit down to start talking about one thing and then end up spending two hours talking about something completely different?

Iain: 2:08:46

there's lots of interesting themes going on in the world of air quality, simon, so why would we not talk about it?

Simon: 2:08:52

yeah, no, indeed, uh, yeah, so uh, part two coming up. Ian, thanks so much for your time. I really appreciate you being so generous with it.

Iain: 2:08:59

Thank, you Thanks. Bye Simon.

Simon: 2:09:03

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