How does an air barrier make your building healthier? (PODCAST)

Tighter building envelopes = healthier occupants

In this episode of PROTalks, we discuss indoor air quality and how an airtight building can help keep building occupants happier, healthier and productive. 


Dave Pennington: Welcome back to ProTalks, the podcast where we take a deep dive into construction to building product manufacturing topics. I'm Dave Pennington, building Envelope group leader at PROSOCO. And today, I'm joined with a couple of members of our team. Do you guys want to introduce yourselves?

Paul Grahovac: Sure. I'm Paul Grahovac. I'm manager of Code standards testing and field support for the Building Envelope Group at PROSOCO, also the risk manager. I do business development work, business to business licensing and such, R and D collaborations, and also the company attorney. Relative to the topic today, I also throw in that I spent six years as an environmental lawyer at a US. Department of Energy radioactive waste facility and also nuclear reactor experimentation facility and became, I'll say, exposed intellectually and not physically to radio nuclei contamination. And there are some similarities, I think, that will come through here about what happens to tiny particles in the air.

Alex Boyer: I'm Alex Boyer. I'm a sustainability specialist here at PROSOCO. I'm a WELL AP and LEEDgreen associate. And mainly my day to day is helping with architects who are looking to use our products on green certified buildings. I help them get their credits and I help them basically plan for how to earn these certifications using PROSOCO products, as well as doing some research on forward thinking research, what the market needs to advance green building and what kinds of products we can create and how we can make our existing products greener and cleaner.

Dave Pennington: . Excellent.Thank you, guys. And thank you for being here today, as you guys have kind of tilted your hand at the topic today, we're discussing indoor air quality and why it's so important to have healthy indoor air for your occupants, especially in light of the recent pandemic. And so let's just get going. How can we make our buildings healthier? Alex?

Alex Boyer: Well, first of all, we spend 90% of our time indoors, sleeping, living, working. It's all mostly indoors. And so when we're building, thinking about building healthier buildings, I think that's the most important thing to keep in mind. It's not just about being more efficient. It is about taking care of us inside the building while we're in there. So the Well Building standard, for instance, denotes that indoor air quality is a major overall factor in our health. And it goes beyond just toxic chemicals. When we talk about indoor air quality, we tend to think of paint fumes or other sorts of coatings or furniture off gassing. We tend to think that those are the leading causes of poor indoor air quality. But truthfully, pollution is the number one environmental cause of premature mortality in the United States. And this is pollution from outside. These are car and energy pollution. And it causes one in every eight premature deaths in the world. So just beyond the worst case scenario causing premature death, exposure to microbes like mold and exterior air pollutants from not just cars, but from nature itself that can cause asthma over time and non asthmatic people and can even worsen symptoms with those who already had asthma. So air quality is really, really important and extended exposure to what's going on outside is a lot of what the Well Building Standard, for instance, wants to try and eliminate with our healthy building codes. So indoor air quality is impacted by a couple of factors, dust and indoor and outdoor pollutants and weather can change how the indoor air is received by building occupants. And a well sealed building can minimize the impacts from those exterior forces and can help maintain the internal efficiency of the air and thermal systems within the building. For instance, filtration, it only works if all of the air that's going through the building is actually going through the filtration system. If you've got a bunch of air leaking in through windows or cracks in the walls or rough openings, then it's not getting filtered out and it's not getting cleaned. So that air can bypass it, it can lead to increased exposure and then when that air is brought in through returns, it can cause efficiency problems over time. So all of those are really important to making sure that the WELL building Standard, especially well but also lead, can help aid in improving indoor air quality for occupants. 

Dave Pennington: Thank you, Alex. Well, we know it's important for occupants, but what about the billing owners?

Alex Boyer: So this is the business case, right? What is important to occupants should be important to owners as well. With a single certification, either the Well Core Air certification or LEED Silver certification for a building, those billing owners are able to essentially charge a little bit more because occupants are willing to spend a little bit more for that. And you're also signaling to your occupants that you care about their health. And this has only gotten more attention over time, especially over the last couple of years with the pandemic, people are spending much more time indoors and they are aware we spend more time focusing on how viruses spread indoors. And this is not unique to viruses, this is all indoor air pollutants. So we now kind of know where do we sit in a restaurant if we want the cleanest air, which is something that people weren't really aware of before. And even beyond that, the Well Building Standard had a commercial during the Super Bowl this year talking about indoor air quality and they brought awareness to it. I believe JLo was in the ad. So it's a big deal that people are really starting to talk about and people are seeing these certifications, well lead, as basically denoting a safe space to return post the pandemic. So we've even seen it. We've been talking about paul, you wrote a paper about how indoor air quality and well-sealed buildings can improve indoor air quality in light of the Pandemic. Do you want to share a little bit about that?

Paul Grahovac: Sure. Back in the fall of 2020, we all have this avalanche of email we get from various entities within our professional area and you try to take a look at it and make a decision about whether to read it. And one caught my eye was by a Passive House building Envelope consultant. Of course, we're very involved with Passive House, which is not only a single family but also large buildings. And a key component of it is the tightness of the building envelope. And this blog was pointing out that actually there was a relationship between adding additional outdoor air to the heating and cooling or HVAC mix or distribution that had an impact equivalent to vaccination. And of course, at that time, vaccination was just a dream for all of us and the vaccines hadn't come out. And so I got real interested in this and started researching and found out that there's been infectious disease studies and HVAC studies dating back to the early 2000s having to do, for example, with the 2003 coronavirus outbreak in China and also influenza studies, which it turns out closely mimics the transmission of coronavirus. So these experts have known this information that I'm going to be talking about and you didn't hear much about it during the pandemic. And HVAC experts have been aware of this information, but they didn't come forward very much either. And it has to do with the increased cost of conditioning, increased amounts of outdoor air. Ultimately, both the Centers for Disease Control and ASHRAE the HVAC engineers did publish documents and guidelines calling for tremendous increases in the outdoor component of the HVAC distribution. But basically the points in my paper were that these studies and research had gone on and that there are two elements of the virus particles. One is what's called the large droplets that fall either on your colleagues or on the ground within 5ft of the person emitting them, and hence the social distancing requirements. But it turns out that by far the more important type of particle is the aerosol or aerosolized particles. These float in the air and move all over the building. And if an infected person is in the building, emitting these particles and leaves the building, and then an uninfected person comes into the building, the uninfected person can be infected by the particles that were left floating in the air by the person who is now gone. Just to let you know how impactful these aerosolized particles can be. The good news is that if you increase the percentage of outdoor air in the HVAC heating. Ventilation. Air conditioning distribution from the 2% which most schools and offices are running pre-pandemic to the 20% that ASHRE the HVAC engineers has always recommended and that. For example. PROSOCO moved too early on even without having any of this information. We're out in Kansas, and I call it just good old Kansas farm sense that it would make sense to bump up the outdoor air in the HVAC, and they did to 20%. They found they could get that much without causing undue problems with increasing humidity. Which is another reason why experts were hesitant in recommending this, because of concerns about humidity. But it turns out at 20% the humidity is not a problem and it has the impact. With respect to the aerosolized particles, it has the impact equivalent of vaccinating everyone in the building and that's just huge. And then with respect to the heavy particles, it's a process of dilution and removal. And with respect to the heavy particles, there's also impact on them such that it's as if you have vaccinated 60%. And this leads to questions about, well, my goodness, can you further increase the outdoor air percentage to further protect people from the large droplets? Or might you be able to do something with the direction and force of the ventilation, which I'll talk about in a minute. But anyway, those are the main bullets and this does require increasing energy use because you're conditioning more outside air. However, if you construct with a type building envelope or retrofit to a type building envelope, you decrease your energy use and can use those savings to condition outdoor air. And you also have enabled your HVAC system to control the flow so that you're getting the dilution and removal that you need to have.

Dave Pennington: That's great Paul. And that paper of yours is phenomenal. Anybody that is listening this podcast really should check that paper out. But why do you think that more building operators have not moved to 20% HVAC outdoor air mix?

Paul Grahovac: I want to address that, but I was just reminded of something Alex said about the general lay population being knowledgeable about and concerned about the transmission of disease within building air. And I just want to mention that I wrote a companion article for the Building Owners and Managers Association called The Great Fresh Air Competition because things I'm reading and hearing people say is that building occupants are very knowledgeable about this and are very concerned about it. And I think one of the main reasons you're seeing people insist on 100% work at home, or at least a significant amount of work at home, is because they want to avoid the proximity to other people and breathing other people's air. And I think we're going to see more and more concerned about this. I was reading some articles about carbon dioxide monitors and how these already exist in some buildings, but you can go out and find them on Amazon portable ones that you can carry around with you. And if the carbon dioxide in a building is low, that means the outdoor air is I'm sorry, if the carbon dioxide is high, it means the outdoor air percentage is low, which means the transmission rate is high. So it's not going to take these young people very long to connect those dots and start carrying around CO2 monitors. But the reason there was so much opposition and I found this on articles where the infectious disease control and HVAC people and in some instances these are the same people have a dual professional identities. But the reason that they were not heavily advocating additional outdoor air was a concern about increased cost for conditioning, air heating, or cooling it, and the concern about humidity. But as I said, if you're not aware, there's nothing more intense, I don't think, than the Kansas Summer humidity. And it's hot and extremely humid, and right here in the middle of that, prosico was able to run 20% and not have a problem.

Alex Boyer: Well, I just want to piggyback off of Paul's point a little bit, especially with people working from home, and they want to work from home because they feel the air quality at home is going to be better. But for many homes in America, we're not running the most efficient indoor air systems. We don't have great HVAC, we don't have great dehumidifiers, we don't have they're not sealed very well. My home is single wall construction. The code is barely met as far as the R value of my home. So I think this can be potentially a selling point for employers and building owners who want to get people back into the office. But particularly those who have owned commercial buildings, they're worried that the work from home revolution is going to change their ability to sell the office space, sell their product. So if you have a well sealed building that has healthy air practices, which varies by your location, obviously, if you're in a denser city with more outdoor air pollutants, you may not want as much outdoor air moving through the building, but if you're in a healthier area, you may want more. If you have healthy air practices and your building is proven to be healthy, odds are that it's healthier than people's homes, and people may want to come back and work from the office again. So it's just a thought that came into mind.

Paul Grahovac: Great to see that happen. That's what I was trying to encourage, frankly, with the Boma article, is to get people thinking along those lines.

Dave Pennington: Yeah, those are great points. So I have a question. Since many buildings leak already through the walls, why not just rely on that instead of using the HDA system to pump that air in?

Paul Grahovac: It's a good question. Word, a term I learned from the PhD scientists and engineers at the National Lab, is counterintuitive. And there's a lot of things in science, it turns out, that are counterintuitive. In other words, one might think if one did not look very far into it, that leaking walls might be a good thing, but they're not. First of all, most building operators run their HVAC system with something called positive fan pressure. In other words, there's fans in that HVAC system to move the air around and you can set your system up in such a way that it's sucking air in through the walls, but that is definitely frowned upon because you're sucking in all the exhaust fumes and pollution. So if you're trying to suck air into your building to get more clean air to fight coronavirus, you're shooting yourself in the foot by sucking in all those other contaminants. So they run at positive pressure, which means that the air is blowing out of the building through the walls rather than coming into the building. So that's one reason not to rely on building envelope leakage for your outdoor air. Also when there is infiltration, such as when the wind blows to counteract the positive pressure of the interior fan, it's not continuous and sometimes there's not enough breeze to do that to counteract deposit pressure. And this can lead to areas in the building where the coronavirus contaminants, aerosolized and such build up the stagnant areas. And then when a gust of wind does impact the building, you're moving that stagnant area that is distributed throughout the building. Another issue that's created by the building envelope leakage is horizontal flow. And there was an extensive study done on this in China with coronavirus showing that if you have your HVAC configured in such a way that you've introduced horizontal flow into your restaurant or office, it's like you're creating a disease transmitter because you're moving air from contaminatedpeople almost deliberately sideways onto uncontaminated people. When an HVAC system is properly configured and operating, the flow is vertical. And in fact, I confirmed with an expert in the field that it's best to have the supply vents be the lower vents in the building and the exhaust vents be the higher vents for lifting these particles out of the air up into the exhaust vent.

Dave Pennington: That's interesting Paul. So with all that going on, if you make those changes, how does implementing a tight building envelope during construction or in a retrofit situation impact this particular scenario?

Paul Grahovac: Well, it does two things for you. First I was just talking about flow remind I'm a big fan of the old western movies and you every once in a while they'll have a house fire and they didn't have fire trucks and such or fire wagons and they'll have a bucket brigade and there'll be hand over hand in these buckets of water. Well, if you're trying to move a bucket of water and it's got holes drilled in the side of it, it's just not very efficient. And if you're trying to have a controlled flow of air, you're building from the supply vents near the floor to the exhaust vents near the ceiling to maximize the removal and dilution of these virus particles and you've got holes in your building envelope that are essentially interfering with that flow, you're shooting yourself in the foot and the other one is the cost. There's a federal study done in 2005 of the existing building stock commercial building stock. And it showed that on average, the buildings in place at that time were leaking at a rate that is 15 times the Passive House rate. And we know that if you use a properly installed air barrier system, you can get Passive House air tightness, even on a very large building. We have an example of a 260,000 square foot school that was recently constructed, and they ran a blower door test on it to see if it would meet the code standard that you can opt into for air tightness, which is five times leakier than Passive House. And the whole school blew to Passive House. So you can have a building that is 15 times tighter than most housing stock just by having a properly installed or retrofitted air barrier system. This has a dramatic impact on costs on a 50,000 square foot apartment building, for example, one built to the current code versus one built to Passive House. The Passive House apartment building will use one 12th the HVAC energy. And this is a tremendous amount of money on the table. So while you're going to be spending more money if you bring in additional outdoor air through the HVAC system to ameliorate the disease transmission, you're going to be spending more money to condition because you're having to condition more outside air. You're also going to be saving a lot of money, probably more. I haven't run the numbers, and that would be a great study, but you're going to be saving a tremendous amount of money on heating and cooling because you're not blowing all that hot and cold air out through the building envelope with your positive pressure HVAC system.

Alex Boyer: It's all about control. As I mentioned earlier, the green building standards are just focusing on making sure they know what the air quality inside the building is. And you can't know it if you've got a leaky building. You can't know it if outdoor air is coming in at a rate that you can't control. So it is all about control and knowledge that you know that the air is healthy.

Dave Pennington: Yeah, that's something. Well, what are some good ideas on how to increase the effectiveness of your HVAC system in regard to the larger droplets?

Paul Grahovac: That's a good question. And it opens up something that I presented recently to the Feministration Manufacturers Association. And it was a presentation sort of in line with this discussion. And these are the top technical people at the window manufacturers. And I said to them, as I would say to anyone in the audience, these issues are too important to leave to the experts on HVAC and the experts on infectious disease. This is not rocket science. As I said, prosecco tumbled to it out of good old fashioned farmers sense. And everybody needs to become a bit of a student of this and needs to become an advocate of this in their offices, in their businesses, for their schools, because this didn't have to be as serious as it turned out to be and knock on wood, should it happen again, we'll be better prepared with this information anyway. Along those lines, I'm not a scientist or engineer or HVAC expert or infectious disease expert, but I joined Ashtray and I participated in the annual conference, I believe it was a 2021. And they did it virtually and probably the top expert on indoor air quality, infectious disease and HVAC. There's Professor Leah of the University of Hong Kong, past president of the International Association of Indoor Air Quality. And he gave his presentation to I don't know how many thousands of people around the world, or maybe more than that. And then he took questions and well, heck, I spoke up and I asked him, I asked him about the vertical flow and whether it should be from low to high. And he said, you know, my colleagues and I have discussed that for some decades now, and we've all come to the conclusion that it should be from low to high for disease control. I asked him whether the larger droplets might be impacted if the velocity of that flow were increased. And he gave me some numbers about how much it would have to be increased. Just under 5. His opinion that would be too much velocity for the comfort of the occupants. But for what it's worth, I did some more research by the big fan industry and there's also something called the Air Movement Association now and both of them indicated that as long as you're under 5 miles an hour, people are quite comfortable. So I think we may be seeing some four or five mile an hour vertical flow in these buildings to address the larger droplets

Dave Pennington: Wow. Do you see any other health benefits, Paul, to a type building envelope?

Paul Grahovac: Yeah. Before the Internet, we used to have a saying that I wish I had a clip, that a person would read a magazine or newspaper and make a clipping of it or make a photocopy or whatever. And so now it's the same thing with all the tons of information we get. We get so much and you try to save it, but you can't save everything or you decide not to, and then bang. That one you wish you would have saved. You wish it were there. But I saw one that said that if you bump the indoor air quality up to the ashray, what I call the ash ray level, approximately 20% from as I said, I believe most schools and offices run about 2% at least prepandemic, you're going to get a 100% increase in cognitive performance. My goodness. Most workers now, certainly many of them are what they call knowledge workers. We're paying them for their cognitive production. And if we could increase cognitive production accuracy and just volume of work by a, you know, that's money on the table. Alex was talking about a business case that's money on the table. Other literature that I see is about all the tremendous increases in productivity that have come from computerization over the last few decades and how that's essentially dried out. We've maxed out on that. We've plateaued. Well, here's a whole new pile of money, if you will, for employers on the table for cognitive performance that they could be reaping and at the same time dramatically reducing the disease transmission in their buildings. So I think that's something people have to look at. Allergies people who move into a passive house, who have allergy symptoms report that they don't have them anymore because the allergens are no longer coming in through the building envelope. And what does get in the house are being filtered through the energy recovery ventilators, which were originally designed to be near 100% allergen removal. So there's a lot of other issues that are going to be coming to light that people are going to be talking about having to do with indoor air quality, increased outdoor air, reduced dust, reduced allergens, reduced disease transmission, and all linked to a properly tight building envelope.


Alex Boyer: I mean, it makes total sense, right? We've all had those days where we've got a head cold and can't focus and can't get anything done and all of a sudden that day is gone and you don't realize that you weren't as effective as an employee and as a worker. So just explaining to people, hey, the air quality matters in those sorts of terms, in terms that they've understood and been in, that makes that business case pretty clear. And that's really everything that the well building standard is all about. If we want to get back to the green standards themselves, it is about unlocking the most potential out of building occupants. And it's not just air quality too. It's light. The tenor of the light, the reflective surfaces within the building and sound and how much outdoor sounds getting in and how much indoor sound from your neighbors and coworkers is getting in, going through walls and areas, these sorts of things. People are becoming much more aware of them. And indoor air quality is just a portion of it. But people are realizing because we spend so much time indoors, why they're wanting to spend their time in those places that are better for them. So we just need to keep that in mind when we're designing the next generation of buildings.

Paul Grahovac: Absolutely. And like I said, we all need to be advocates and speaker. Mine.

Dave Pennington: Yeah, I think you guys have made a powerful case for airtight buildings today. And I know that if I could increase my cognitive performance 100%, it would sure cut my coffee bill every day, but really good stuff, guys. I'm really hoping the industry tumbles towards all this information and starts making these changes just for the benefit of humanity. But it just makes sense. And I think building owners, if they run the numbers, can see that they can provide a better product, get people back in their buildings and save themselves some money. They just have to look at it. So thank you, guys. Paul, before we leave, though, you want to tell everybody your article is fantastic, and anybody that wants to read that probably like to know where they could find that.

Paul Grahovac: Yeah. One, you can go to the Prosuco website. I believe it's linked. There also at the International Institute of Building Envelope Consultant. That's Ibec. I believe it's available. There certainly available to members, and there should be a way you can obtain it yourself. But if you have any issues at all, just call the Prosico 800 number and I'm sure they'll figure out a way to get you a copy.

Dave Pennington: Excellent. Well, thank you, Alex. Thank you, Paul and I look forward to our next talk.

Alex Boyer: Thanks, Dave.

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