#10.2 - Paweł Wargocki: Mastering Air Quality and Ventilation for Health, Productivity, and Sustainable Building Design

Part 2 - Pawel Wargocki -  was recently promoted to Professor at DTU, Technical University of Denmark.

He’s the Past President of the International Society of Indoor Air Quality and Climate.

Previously, served as Chair of ASHRAE Environmental Health Committee and the Position Document Committee, Secretary of Academy of Indoor Air Sciences, and currently serving as a  Director of the International Centre for Indoor Environment and Energy.

Hel is an indoor climate scientist and expert, he teaches at undergraduate, graduate and Ph.D. level courses, and supervises several Ph.D. and numerous M. Sc. students.

His research has influenced the development of indoor air sciences, and it is hard to overstate the impact he has had in this sector.

He continues to be involved in fascinating research on the impact of air quality on performance in the workplace, health and performance in schools, and the impact of air quality on sleep. He is behind a fascinating standard for assessing IEQ called tail and the list, honestly goes on.

Pawel is one of my favourite people to talk to in this space, he is respected, experienced and sometimes outspoken. But always great value to spend around.

We talked about so much in the episode, including his work on tail, how we are doing a characterisng air quality in general, some of his work on sleep and quite a bit more beside.

Pawel Wargocki - DTU
Linkedin - Pawel Wargocki
TAIL - Indoor Environmental Quality

Transcript

Simon: 0:00

This is Air Quality Matters, and welcome back to part two of my conversation with Paweł Wargocki. I think the value of risk framing is that it identifies the gaps, and in the gaps lie the opportunity to frame the benefits. That's where industry generally steps in and starts trying to sell stuff. But it has been very true for me, certainly through the pandemic, that risk has been a very useful tool for framing ventilation and air quality, because it doesn't have to operate in the world of absolutes. It can make a judgement call. People's tolerances of risks are different. It has ways of managing risk without having to have all of the answers. The hierarchies of control have been around forever and are a very good way of managing risk in the building environment. But it's in those gaps that are identified through that process that those opportunities lie, and that's where we need to get better at building the business case.

Simon: 1:21

Perhaps and I think you and I have been around long enough to know that probably the solutions to all of this is going to be everything. It's not one thing or another. While there's a lot of carrot opportunities out there, we also need the stick, and that's where standards come to bear. But standards have struggled with air quality. I think it's fair to say they've tended to hold in the world of a rollic performance and ventilation performance and not strayed too far into air quality, because there's been an uncertainty in drawing a line between air quality outcomes and health outcomes. But I think we're getting there. But we're seeing a lot of standards starting to pop up now that are thinking about air quality, whether it's lead or well, or Bream or reset or air rated or indeed tail. We're starting to try and frame air quality now within our built environment standards. Tell me a little bit about tail and where that project came from, because originally it was an academic project. I think that developed into a standard didn't it really.

Pawel: 2:40

Well, we hope it will develop into a standard, either tail or any sort of a similar metric or rating scheme that can be developed, and the tail is sort of a prototype of that. Coming back to your standards of lead Bream and all, I think those standards used credit points for assessing air quality, so they do not are indoor environmental quality generally, so they do not address the actual conditions. In a sense they only provide the credits for achieving a certain levels, which then it's very difficult to assess how many credits you should get for one type of a solution or another. Although I feel that this is a very important part, that it is integrated in the overall strategy for certification of a building, that the part of the indoor environmental quality although very small percentage of the credits is given to this, but there is some credits given it is important sometimes it is forgotten today when we talk about decarbonisation very often the groups that they talk about decarbonisation do not even consider indoor environmental quality as an important topic to be discussed.

Pawel: 4:22

But coming back to tail, tail is actually how to say. It's sort of a random development or we did not plan it. So I did not have a plan in my research that I need to develop the rating scheme or we need to develop rating scheme. So maybe I had it, but in the back of my mind it was not like my priority. So I have had a lot of discussions with the industry and the industry was actually complaining about the lack of possibility to document the effects, and always they were referring to productivity or the work efficiency that they had no any metric that they can document this. So this is why they are not introducing this information or applying it in the buildings. But then I started to understand that probably the problem there is more related to the fact that we do not monitor the conditions in a building, so that if we can monitor conditions in a building and compare the conditions in a building and then on top of that levels that we monitor, we can attach some information about the harm that is generated or consequences for learning and productivity, then we will probably be better off and much easier communicate this information to the industry. So the opportunity arise during a project that was called Alderen and this project Alderen was the European Commission funded project that actually focused on creating arguments to increase the number of retrofits, deep energy retrofits in office buildings and in hotels. So the idea was to in which way we can provide the strong arguments that this is the way, how, that it's a good investment basically to do the retrofit, and among many ways. There are many arguments that were discussed. One was building a building passport, one was to avoid the gap between simulation and actual performance, and then there was some sort of calibration or development on a standard simulation tool so that you can, with a simulation, compare the buildings across each other.

Pawel: 7:15

There was the development of the methodology for the rating of indoor environmental quality, but it was not very well defined at that time. The idea was that, according to the EPBD, which is energy performance of building directive, any energy retrofit should not generate the risk that for health and comfort for building occupants, meaning that you should at least stay at the same level as it were, before retrofit. And then, once you document this, there was also another issue is was the economic benefit that is related to the retrofit, from the energy saving, but also from improving indoor environmental quality. So what we did is we tried to scan the literature to identify some sort of measures of indoor environmental quality or what are the measures that are used or recommended in different standards and certification tools, and we found out that basically there is no any standards. So different standards, different certification tools and different groups that are making measurements of indoor environmental quality in buildings use different methods and it's very difficult to compare across those measurements because of course, there are some basic parameters which are the same but they are different. So we were not able to sort of say, okay, if we refer to that standard, we could use this type of metric to measure indoor environmental quality.

Pawel: 8:59

And we decided to develop our own rating scheme, and that happened basically overnight. I had a dream about tail, to be honest. It happened like this, and then I presented it to my colleagues from France and then we started to develop, build on this idea of having four components of indoor environmental quality and have a very crude methodology in a sense that it can be applied in practice. So we didn't want to develop anything that is too sophisticated, so it could not be applied. So if you have to, let's say, measure a pollutant with the sophisticated instrumentation, analytical instrumentation, that will cost a lot of money, no one will basically apply that. But at the same time we want to develop something that has some fundament, so it is reliable, and also we did not want to develop our own reference exposure levels or reference levels. So what we wanted to do also we wanted to refer to the existing standards and documents and guidelines.

Pawel: 10:23

So in this way we developed tail, which has four components thermal and only temperature in it. That refers to the standard. Then A, which is acoustic environment, again only sound pressure level, to be debated whether this is a good, but it is in the standard. So we selected this one. And then I, which is indoor air quality I come back to this, it's much more complicated. And L, which is luminous environment, the visual environment, and here we wanted to address two aspects is a daylight, which is very much debated and we have methods to simulate daylight factor and then overall luminance level. And then I, which is indoor air quality, and here we had a lot of troubles because this is basically CO2 and ventilation rate, ventilation rate difficult to measure, but it's in the standard, so we had to put it in. And CO2 also does not actually provide information about the overall pollution in a building, but it is measured and referred to. So we included it.

Pawel: 11:43

And then we included other parameters which are on WHO list and extended it with mold, which because of the hotel issue, sort of a residential, and then we also and I think that's all, and I think we covered very well and selected only few pollutants, not all of them. So we wanted to represent the pollution that is, or the pollutants that may come from outside, and then the pollutants that are in those sources. So we have formaldehyde, we have benzene, we have a new tail for schools that has not been yet we did not publish yet the paper which where we have also NO2. And we also have a reverberation time in acoustic parameter but nevertheless. So we wanted to represent the exposures or the pollutants that have indoor sources and outdoor sources, to extend out this information that it's not only CO2, that is sort of a marker of all the types of pollutants, but also that we have ingredients that are coming from outside and from inside other pollutants.

Pawel: 13:06

So one important topic about tail is and there's a lot of debate about this is that we do not compromise on any of those pollutants. So if any of those pollutants is of any of those parameters is the lowest class, the overall indoor environmental quality is considered as the lowest class. So the idea here is that we do not weigh the components against each other. To say, in many other systems there is a weighting method that is proposed. Usually it is equal weighting, so you would say 25% to T, 25% to A, 25% to I and 25% to L. In our approach we don't want any of those parameters to be compromised, in a sense that because we don't know their combined effects, we can come back and discuss combined effects here. So because we don't know, so better not to compromise any of those. It's a similar to what is done with the ambient pollution, some of the ambient pollution metrics and water, where the quality of water is determined by the pollutant with the highest concentration right, not average, of the pollutants that are monosodes in the water.

Pawel: 14:41

So we wanted to use the same approach here.

Simon: 14:43

To steal a term from some of the other standards that there are some preconditions baked into that. That means that if you're above a certain threshold you get a zero score or a low score, regardless of what the others are. It's not a combination of all of them, because otherwise you'll end up with a TVOC effect, won't you? You can have a relatively decent score but a very high level of one pollutant and none of the others, and still have a high risk. So you do need to countenance that with. Look, if you're above this threshold, that's it. You know it's a poor score. Do you apply any of that logic to any of the other parameters in T and A and L? Are there certain thresholds that if you go?

Pawel: 15:29

I'm trying to think we come off if it's below 60 degrees? Yeah, because we, I think, accept the WHO I'll have to recall but at least what we do is we have a certain bands in which the parameter can occur, so it's not a single threshold approach. So I have participated once in a debate where people were complaining about the red lines that are created, For example, if standard defines 23 degrees. So if you are 23.1, it means what? So you're outside, are you still? You know so? So what we created is a band.

Simon: 16:18

Ben makes the same argument with the harm indexes is that a threshold is useful but it doesn't tell you what happens if you're 10% above it or 10% below it. It doesn't give you a weighting of any description. It's quite binary and similar with what you're saying there.

Pawel: 16:39

Right, I mean. So we have a certain band and if you are in this band, you will still, you know, meet the requirements and then you will stay in that class. So we don't have single thresholds here, which also we need to be reasonable. There are no instruments that will be having that accuracy.

Pawel: 17:03

So, we need to allow for a certain and no one will die if it's 23.1, you know here. So we have to be reasonable, so we also accommodate this. We provide information on how to perform the measurements and so on. So we develop a sort of a system for rating the indoor environmental quality. It's pretty simple. It is based on the evidence that is out there, so it is not something that you know sort of we come up with some new information. We basically what we did is we put together all the information that is there and we put it in certain framework, in a sense, and it seems like many people like it because of many reasons. I don't know why, but maybe this is one of the reasons. That is actually something that has been already in use, but put in a certain, you know, frame that can provide information.

Pawel: 18:11

Tail was introduced during the pandemic in 2020, so many people didn't know about this and now it is coming through, more and more groups are getting to know it. We try to develop the sensor for tail, a sort of a set of sensors, and if we have it, we will make it public so anyone can build the sensor for themselves. There are other risks related to that we haven't discussed this about the sensors. It's the cross-calibration of sensors, something that the issue that has to be very strongly addressed. The fact that you have the same sensor, even from the same producer, may not mean that the sensor is measuring the same thing. You need to have some form of cross-calibration, some sort of a meter, a standard meter, like we had in the past in France, that we can compare against.

Pawel: 19:16

We want to make it accessible in a sense, so we don't want the tail to be an exclusive solution for the exclusive club. This is not the criticism of certification schemes and other standards that are available, but we want the tail to become an inexpensive method of monitoring the environmental quality. Our interest is that we start to develop a sort of a benchmark against which we can compare the different environments, because this benchmark is a limiting factor of developing the solutions or maybe looking at the already existing solutions which perform very good. This is also the area that we have not been discussing and coming back to that risk reduction. We are in all ways focusing on buildings that underperform rather than focusing on buildings that perform very well. What is it that caused that those buildings are performing very well compared to the other buildings?

Simon: 20:32

That's the value of some of these standards. You're going for a job interview and one of them is a platinum lead, well building, and the other one isn't. Which one are you going to go for a job in? It's that competitiveness of the market that is one of the carrots that I think we can use to push this, I agree.

Pawel: 20:55

Then it can also be introduced even as a carot when you talk about the residential environment. You were looking for a business case that can create a business case. We are considering how we can put a somehow put some economic value on those different levels that were defined in tail. Even if they are small, they can provide maybe sufficient argument sometimes or incentive for making a decision to improve the environment.

Simon: 21:38

I agree. I think the risk and to play devil's advocate at the moment is that there are so many organizations in this space at the moment. We've just seen lead version 5, I think it has come out that has now got more of a focus on air quality. Well is making very good inroads into real estate, but they're just releasing a residential standard which will score individual properties. It's a once off test which will provide that competition.

Simon: 22:13

Look, I'm in a house with a 76 score and you're only 45 next door. Why is that? Well, because that's because I've got the cookahood extractor and you haven't kind of thing. So there's a lot of those kind of standards. And then we have others like reset and air rated and a whole bunch of them.

Simon: 22:31

The risk is it there's a lot of noise and while you need competition, you could also create uncertainty with that as well, of what is the right standard. You're right, and it's an interesting difference, I think, between tail with the likes of Well and lead. While there are certain preconditions you have to hit, they're very limited, that you know. They'll only generally deal with not smoking and some basic air quality parameters, but beyond that they're not. You don't really get a score per se for the air quality of that building. It's the building as a whole is achieving a certain standard.

Simon: 23:13

So there isn't a lot of stuff out there that says, actually this is here's a number on it that you can actually lead to is not necessarily a threshold and a standard, but at least a target. Say, look, I want this building to be at least a 75 or 42 or whatever good looks like we're not really doing that very well. The risk is with industry is that the moment this gets traction and any element of industry sees it as a risk, you find it will come down pretty heavy on it pretty quickly because they'll think it's going to risk sales of X, y or Z. And we've seen that. We've seen that with the latest recast of EPVD being watered down and watered down, and watered down and watered down, and we know where that's coming from, but that that that there is some.

Pawel: 24:07

I don't know whether has it been published already.

Simon: 24:12

I think it went through the tri factor factor, whatever it's called, and has been published. I think indoor environmental quality was, or I think indoor environmental quality was kept because it was fairly generic but they didn't focus on indoor air quality very much. There's some concerns over controls in. In non residential setting, controls are generally managed by the controls industry, which is fair enough the Schneiders, the Johnson controls of this world but in the residential sector control of air quality is generally managed by the ventilation industry and I know there's been some concern that they haven't separated residential from commercial and and it means that there isn't a clear home for the control of air quality in the residential sector, because Schneider isn't going to be controlling the residential sectors buildings, you know whereas they will the Deloitte headquarters building in Frankfurt, I'd say.

Pawel: 25:11

But I have seen the approved version of the one that is bolted on and but I'm not sure what is public, so I'm not sure what I can be talking about it, but that there is an important maybe I can say few words is. There is an important statement, is in this article 11 that that says that each member country, shell, and I repeat again shall develop the measures of indoor environmental quality. So in a sense, there have been debate about whether what was proposed in the earlier version of this article would be approved by different countries, but now those proposed parameters are removed, all of them are. Basically there's none, none, none of them is mentioned. But there is this an important statement that some ways of monitoring in the environmental quality shall be developed means that they must be developed Right. So that is that disadvantage that different countries will develop different ways, different methods, and again it will create you know the situation that you cannot compare and but maybe in the you know the global economy that we have in the end there will be a similar way.

Pawel: 26:43

Epp did not want to take responsibility for this, I think so. Probably what they are saying is they call for establishing, establishing a different committee is to discuss that, how to do it, and one way of doing it is basically to look what is out there and maybe adapt it. One way of doing it is maybe to pick up tail or any other scheme of framework that can fit in or build on this. So what I'm trying to say is tail can be a sort of a fundament and then if you have tail in any measurement or any metric that you develop, then you will be able to compare at least on that set of parameters, if you want to add more parameters at them maybe they should be even reduced tail, I mean, who knows?

Pawel: 27:34

but at least we need to have a certain core of parameters that we agree on, because that will allow us to again. I repeated over and over again. So we really need to somehow create benchmarks, and the best example for me is iPhone or any other smartphone. You know that they basically develop from year to year with a new model, but the development of the new model is based on the information that was collected for the previous model. What are the needs? What are the preferences? Which part do not work? Which work? And we don't have that in the build environment. We don't have that metric or that methodology.

Simon: 28:24

Actually, you can't manage what you don't measure. You know it comes back to that every time. Where can people find tail if they want to go?

Pawel: 28:33

Well, I'll put a link actually in the podcast for people to go to, and then we have open access article. Together with this we developed so called predict tail, because after we develop tail, people were complaining what about the designers if they want to achieve a certain level of tail and the building is under retrofit or is being built, so what they should do? We sort of develop the methodology on how to predict, with the simulation tools, what the level of tail could be in a building or what decisions that you take during design process how they will affect the components of tail. It's probably more like this the actual tail has to be measured in the actual building. So it is a methodology of how, to say, navigating your decisions. So certain decision may have an effect on energy and then maybe they will reduce significantly energy, but they will affect some components of tail. So then you can basically value them against, away them against each other Brilliant.

Simon: 29:48

We'll leave EPBD behind, because I think that's one for the beginning of a podcast rather than the end of a podcast. I'd love to hear a little bit about DTU Pavel, because I mean Any ventilation paper that you seem to care to look up will either have you or one of your colleagues excited on it, it seemed. I was very luckily, a very lucky to be Given a tour around your facilities there Last year, and it's an amazing place, from aircraft fuselages to Atmospheric chambers Dating back to before I was born, that there's a an amazing heritage there in DTU. Isn't there on ventilation and air quality, describe, describe the place to us? It's hard, hard to picture it.

Pawel: 30:41

Well, it's located north of Copenhagen, very beautiful area. There is a huge campus and there is a one building Its number is 402 and the other one is 412, and where our group is located, in building 41 two of our 12 we have our facilities and this come Embrace like 12 different types of chambers. So we have a classical Atmospheric chambers I was a climatic chambers. There are few that are made of stainless steel and there is one especially developed for the thermal comfort studies. Interestingly, there is still the old chamber for the thermal comfort studies which is in the building in the work in the past that our University was in the city, and there's still.

Pawel: 31:40

In the basement of one of the building. There is an old chamber when some of the work on PMV was done, actually over that as well, but we don't use it, we use only the chamber here. Then we have a three larger chambers in which of in one of them we have a mock-up of Boeing 300, something I don't remember, which number eight, three, seven, I think eight, three, seven, I think something like this. And then there are two other chambers which I use now for some energy research, and one is actually converted into the bedroom. Then we have a normal office spaces, which were no one's Chambers that we called field chambers. These are spaces normal office spaces that were converted so that they can provide Space for the research with human subjects or any other research, and they are not that well-controlled as the climatic chambers.

Pawel: 32:45

So all the way, there is 12 of those, and so this is very unique facility in a sense that we can do the fundamental studies, we can do something in between fundamental studies and actually we can even model the now you call it a Living lab is sort of this field laughs just a living lab. And then of course, we can do the measurements also in our offices. That would be the classical living lab, but we know too much about this, so it's better not to involve us in those experiments. So this is what we have. Then we have instrumentation that support the measurements and we have collaboration with other groups that would provide necessary instrumentation to us. For example, we don't have very sophisticated Instrumentation for the chemical measurements, but we have collaboration with other groups that can provide that measurement and they would. They are interested to come because of the facility, basically because we can perform the measurements in parallel in different chambers. So this is very unique.

Pawel: 33:51

But I think the uniqueness of the group is not only facility. It's also how many people there are that are working on a similar Not on the same, but on a similar topic. So we have like group of 20 people who are working on the aspects of indoor environmental quality from different points of view. Some people look at the exposure, some people on a human behavior, some on the thermal environment, some of the energy impacts of those. Some people are working on fundamental research, physiological responses and so on. So we can provide a wide spectrum of the results that base and also we can learn from each other. So in many groups that are maybe one or two people, or three people that at the maximum that work on this topic, here we have, like you know, the big group that can do and also we have a lot of guests coming in so they would like to be a part of this and participate in this research. So this is the advantage.

Pawel: 35:05

I think the huge advantage is that we are so many people working on that topic so we are not Isolators.

Pawel: 35:10

I'm not isolated in my office doing my research only on indoor environmental quality. Next door there's another person also working on indoor environmental quality and down the corridor there's also someone. So that is the advantage of that and this is why it has been built over many, many years, starting with the lab doing mostly the work on thermal environment and developing into our quality. And in 98 we got substantial funding from research council that allowed us to sort of a develop a school of indoor environmental quality, and we are still, fortunately, are able to do it and generate sufficient funding to support our activities. Most of our activities are from external funding, so we accept for the salary to some of our employees, basically the, and of course the contribution to the facilities surrounding facilities, because the energy and so on and then you know they are in the building. So, but except for that, we bring all the research funding from outside, not from the university. Does Denmark have a building research organization like similar to the CSTB and the BRE in the UK, or does that?

Simon: 36:31

tend to come out of the academic institutions. Now, we used to have, and then there was a reform, maybe 10 years ago or something like this, when those research institutions were integrated into the university.

Pawel: 36:47

So most of them they are part of the university and we used to build we had a building research institute called SBI in the past, similar to building research establishment in UK and CSTB in France, and so on and so on. So we have a building research institute called SBI in the past, similar to building research establishment in UK and CSTB in France, and so on and so on. But now it's a part of the Alborg University or that group is a part of the Alborg University. So we don't have as such but we have within the universities. This research is covered and also they still perform substantial amount of work for the government. So there are some sort of projects that are offered by the government for them to perform.

Simon: 37:37

And how did you end up in DTU? You're now a professor at DTU, congratulations.

Pawel: 37:45

Thank you.

Simon: 37:46

What was your journey into indoor air quality? How did you find yourself where you are?

Pawel: 37:52

Those who are not, who are on LinkedIn, can read about this long journey. It's a very short description of that. All of it happened by accident. So I am a graduate of the Warsaw University of Technology and actually, interestingly, my master thesis was on heating. It was not on air quality. At that time I was not at all interested in air quality or indoor environmental quality as a whole, because now this is the area which I am stepping in and I start to appreciate how important the other domains are, but not now. I have appreciated them all the time, but I didn't have opportunity to examine that or study that. So, interestingly, the topic of my master thesis was to.

Pawel: 38:47

We were developing the heating system integrated with the extract ventilation, and we used the heat from the air that was extracted to heat the domestic hot water. It was in the 90s and at that time it was very modern. Later on in Denmark I don't know whether the countries they maybe still use, but in Denmark it was very popular basically to use domestic heat water by reusing the energy from the extractor in dwellings. So and I came to Denmark for a short stay as a student and I met Fanger at that time and then, when I started to work at the Warsaw University of Technology. I applied for additional funds, for extra scholarship to come back to Denmark because I liked the area. The discipline Fanger introduced to me sensory ratings of our quality. We were actually working on a project in which we looked at the fragrances and how they affect whether we can mask the bad odors with fragrances. Basically and just to explain we could not.

Pawel: 40:14

People prefer clean air from more than fragrance added air. But anyway, and then I come back in 1993 for a four months period, which was extended, I was invited to participate in the project developing actually standard atmosphere, representing the air that is in the buildings. I was able to develop that, but we were working on it and then I applied for a PhD. I got a PhD and at the end of the PhD our International Center of Indian Environment was formed and I got the offer to continue the work here. So I mean I did not plan it from the start.

Pawel: 40:59

In fact my parents played a very important role because I, when I came as a student to Denmark, I was applying to go to UK and then I got the offer to come to Denmark and at that time I didn't know much about Denmark. To be honest, I'm sorry to say that for those who from Denmark who are listening to our podcast Basically I did not know much about Denmark, but my parents convinced me to go and then I met Fanger. My most important research during my PhD was done actually outside the period of my PhD, when Fanger asked me oh, why don't you do an additional experiment? And then it turned out to be the most important experiment, so all of it happened by accident in a sense. But it is a nice flow and I'm very happy that it happened.

Simon: 41:53

And for those who don't know who Fanger was, he was one of the pioneers, really, in the indoor environment, wasn't he? Yes, exactly yeah. And what kind of stuff are you working on now? What are the projects that are pushing your buttons and getting you excited?

Pawel: 42:12

So of course we don't have a sort of a. We have some small funding now for further developments. So there is a development for schools. We have a PhD student in.

Pawel: 42:25

CSDB in France, who will be delivering his thesis soon. So we adapted Tail to Schools. We hope that this adaptation is really an important step and we will present some nice results to document that. And then in Tail we also try to develop the sensor for Tail, tailmedia in a sense and then try to put some economic value on those different levels as well. So Tail is sort of a development that is ongoing.

Pawel: 43:00

Then I mentioned sleep research. Actually, the last three or four years that have been very intensive sleep research that was taking place here. We have less activities now on that topic, although there are some students who are interested to perform, so we can do with a smaller resources to continue where we looked at the effects of ventilation or air quality or sleep quality, and we sort of developed the levels of ventilation that are necessary in bedrooms to avoid disturbance to sleep. We don't know the physiological consequences of that, but we think that it is probably. This is where we should be. Now we want to further advance this and look at the aspects of overheating because the climate change. There is a lot of research on sleep and thermal environment. We want to figure out how we can, where the limits are. So what would be the sort of a threshold temperature in bedroom to avoid sleep disturbance, because we can adapt, of course, with our clothing and, of course, a duvet and bed linen. And then also particle pollution. We found that particle pollution is important for sleep. We also look at the low relative humidity. Actually, we are running now the study in which we look at the low relative humidity effects on sleep. Humidity came back to and there is a lot of discussion about humidity because of the pandemic and the influence impact of relative humidity on viruses. And then it's open up the debate about what is the low relative humidity level that we accept. Is it 10%, is it 20%, 30%, 40% and so on. So this is the sleep quality research.

Pawel: 45:05

Then we start the important research. I think that has not so much research on this. It's the interactions of different parameters in indoor environments. Again, we never exposed indoors to only light or only noise, or only elevated temperatures, for example, are only pollution. We are exposed to the mixture of all of those parameters. So we need to understand how they act on each other and how they in those different combinations, how they influence our responses.

Pawel: 45:48

And we have two students which will look at this aspect. And this is interesting because what we want to understand is the two points here. One is our limits of adaptation, because if we talk about the energy and reduction of energy use and reducing the impact on climate change of all the solutions that we use in the buildings, we need to understand where are our limits of adaptation with respect to the different parameters in those, and so this we will be looking at this, but more in a complex way, in a sense, looking at all the parameters, not only on one parameter, and for this purpose we will be trying to establish the some sort of a model that defines how those parameters interact and affect our cognitive performance. This is a very complicated topic and we have to be very, how to say, prudent in a sense, that define exactly what we want to do here, and we will probably focus only on offices here, maybe with some interest also, look also a little bit on the schools, but mainly on offices, and see, under certain conditions of the different indoor environmental parameters, which of them they will be inhibiting and which will be promoting our work, our office work.

Pawel: 47:24

There is another topic, and I will be speaking about this during my inaugural talk for the professorship, which will be on March 8th actually, and I intend to have it online, so if you're interested, you can join Is what measures of cognitive performance we should use now, with the prevalent use of artificial intelligence. So what is it? What kind of skills that we should be looking at? So this is another topic that we will be considering here, and the other topic is more related to creating, again, incentives for improving indoor environmental quality, on how much we are willing to pay for improvements to indoor environmental quality or how much we are. On the other hand, we can look how much we are going that we are able to sacrifice.

Pawel: 48:18

So, in a sense. So it's looking from two different situations. So if we want to create indoor environmental quality which is optimum or the best for us, how much we will be, how much we can pay for it. So are we, we will be like for the utilities, you know, for the electricity and for the energy we pay.

Pawel: 48:43

So now, what about if we want to create the optimal thermal environment? So how much we can, actually we can pay for it. And then, on the other hand, we can think about is where are again, our limits? You know of adaptation, so what, how much we can sacrifice because of the high cost, for example, with no negative effects. So, in a sense, if creating the optimal thermal environment, or maybe low temperature that I prefer, will cost me a lot of money, so where is my level of, you know, where is my threshold that I can accept maybe slightly elevated temperatures with no negative consequences for other aspects of life, of course, our wellbeing. You know life quality, to avoid not to maybe over cool, for example, or not to over ventilate or something like this.

Pawel: 49:51

So this is another area that we will be looking at.

Simon: 49:54

It sounds like DTU is one to watch. Then over the next few years there's going to be an awful lot coming out, as ever. Pavel, that's been fascinating couple of hours with you, as ever. Thanks so much for your time, I think.

Pawel: 50:08

I'll be fine.

Simon: 50:09

I look forward to catching up with you soon and I'll be sure to log into the inauguration. And that sounds like a fascinating talk also.