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ASHRAE Journal Podcast Episode 35

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Tina Brueckner, Member ASHRAE, and Jennifer Isenbeck, P.E., Member ASHRAE

Guideline 42: Enhanced IAQ for Commercial & Institutional Facilities

Indoor air quality (IAQ) has consistently been a sticking point with facility owners and operators. Join Tina Brueckner and Jennifer Isenbeck as they discuss how engineers, industrial hygienists, and other practitioners in the industry can follow ASHRAE Guideline 42 Enhanced IAQ for Commercial & Institutional Facilities to enhance indoor environmental quality for occupants.

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  • Guest Bios

    Tina Brueckner, Member ASHRAE, is the Senior Engineering Manager for the Engineering Development & Design (ED&D) Team for Energy Systems Group’s Federal Business Unit. As Senior Engineering Manager for the ED&D Team, she oversees the team that provides schematic and detailed design submittals, detailed scopes of work and measured and verified savings for the technical solutions on performance contracts. This includes leading a group of subject matter experts and technical resources that provide their expertise to the project team during development and providing oversight of the design intent during construction and as the project commissioning resource. In ASHRAE, Tina is currently the Subcommittee Chair for Guideline 42, a member of SSPC 62.1 and serves as a Section Head on TAC. She has been involved in ASHRAE since 2002 and is active with her chapter and region. Tina was Director and Regional Chair for Region VI from 2010 to 2013 and has served on the Members Council, the Planning Committee and the Nominating Committee and was RVC for Student Activities. Tina has a BS Electrical Engineering from Milwaukee School of Engineering and is a Certified Energy Manager and LEED Accredited Professional.

    Jennifer Isenbeck, P.E., Member ASHRAE, is a staff engineer in Moffitt Cancer Center’s Planning, Design and Construction Department. As staff engineer, she assists with the design, construction and implementation of mechanical, electrical and plumbing elements with new and renovation construction. Her previous roles have been in Facilities Operations (project management, maintenance, grounds, ES) for institutional and corporate entities as well as a consulting engineer for 10 years. Jennifer is immediate past Chair of ASHRAE Std. 62.1, Ventilation and Acceptable Indoor Air Quality (2019-2022). Currently, she is on the Standards and Publications Committee, is SPLS liaison to 90.1, 90.2, 90.4, and serves as a member of various other society committees. She was on the ASHRAE Society BOD as Director and Region XII Chair from 2013-2016.

  • Transcription

    Tina Brueckner:

    So I'm Tina Brueckner. I am currently the subcommittee chair of Guideline 42, working for Standard 62.1, and I've been involved with Standard 62.1 for about four years now. During that time, been working on the subcommittee and working with folks and been involved with IAQ since the beginning of my career, which has been quite a few years now, and I'm very interested in it. And I actually took over Guideline 42 from Jennifer. And I guess Jennifer, can you give us an introduction of who you are and why you got involved with 42P at the time?

    Jennifer Isenbeck:

    Absolutely. First, my background was a consulting engineer, and then I worked as a facilities director. So for the most part, my career has been either consulting or on the operations and representing the owner. And so I was approached by one of my ASHRAE mentors, along with—Ross Montgomery, along with Hoy Bohanon back in 2015. And they asked me if I would like to be involved with ASHRAE 62.1. More importantly, what Hoy wanted to do was ask me if I would be subcommittee chair of the 42P Guideline, which began the journey of this document. And that was back in 2015. So I'm happy to say it's finally been published.

    Tina Brueckner:

    Yeah. And I know that even prior to 42P, there was an ASHRAE IAQ Guide written in 2009, and I believe that that was a funded effort. But the great thing about some of the stuff that we have going on in 42 is we now took it even further, but we used a lot of that relevant material from IAQ Guide.

    Jennifer Isenbeck:

    Yeah, that was a great foundation for a lot of our work. And I wanted to also commend some of the original members of the—people who were involved with the IAQ Guide, were also either current or past members of 62.1, and they have continued on with the tradition. So I wanted to also give recognition again to Hoy, Wayne Thomann, and Tom Phoenix, Barney Burroughs, and, of course, Andy Persily, looking through that IAQ Guide from 2009 and then seeing it follow through that here, the same diligent volunteers, I should say, have participated in the publication of this new Guideline 42 enhanced and indoor air quality.

    Tina Brueckner:

    Yeah. And I know there's several others we're probably forgetting, but there's been so many people involved with this.

    Jennifer Isenbeck:

    Yes, there's been a great industry mix of experts. And then I did want to comment that a lot of them are industrial hygienists, a lot of them are indoor air quality scientists. We could not have done this without some of the practitioners in areas that myself, who is an engineer, do not normally get to have that experience with.

    Tina Brueckner:

    So, Jennifer, I do believe that that IAQ Guide is still available. Is that your understanding as well?

    Jennifer Isenbeck:

    It is. It is. It's available for download free if you go to And that 2009 guide still has tons of relevant information. And that was one of the things that I know you and I and others had talked about is if we reference the IAQ Guide, would it still be relevant? And I think you can say for yourself after your editing and whatsoever that it is definitely relevant.

    Tina Brueckner:

    Absolutely. A lot of things have been updated, but it's still very, very good information for reference. So, Jennifer, you had talked about that when you started out on this. What was some of the first experiences in getting this kind of kicked off?

    Jennifer Isenbeck:

    It was just first meeting at winter and annual meetings and doing some of our usual online web things. But I think one of our first most productive meetings was meeting in person in Atlanta. And again, I have to commend all the volunteers who came on their own time and dime to come to ASHRAE headquarters when we did have a weekend working session. And I learned a lot too. Again, referencing my background, I didn't have a whole lot of folks that were industrial hygienists that I worked with and scientists. And so I learned about the four P's for the first time in my life from Don Weekes and Charlene Bayer and it's pressure, pollutants, people, and pathways.

    So there are various contributors to indoor air quality or poor indoor air quality or better indoor air quality. And surprisingly, it's not always about the buildings that we have to cool and heat the air. It's also the constructability of the buildings, the operations of the buildings. And again, that kind of led into the format of how Guideline 42 should be written. It kicked off a whole controversy of how we should outline not only 42P, the guideline, but was it going to change the way we would outline 62.1. And I think, again, seeing the merits of that, maybe you want to talk about what it did to change 62.1.

    Tina Brueckner:

    Yeah, really when we looked at, to your point, during working on this guideline, we talked about reorganizing all of it to make it make more sense to the reader. And so a lot of that is we reorganized it so that both 62.1 and the guideline are based on the airflow starting outside and going all the way through the building so that we had an easier way to understand how the building impacts the people that are in the building.

    Jennifer Isenbeck:

    Thinking about that, I know some of the challenges are of, well, not only what people say about the ventilation rates that are written in 62.1, but where does the information come from? But now, having to write this guideline, fortunately, thankfully, it's a guideline and not a consensus standard, but the first APR, which is the advisory public review, so it wasn't even a real public review, went out back in May of 2018. So again, we've been on these little periodic updates. And back then, we had tons of comments, mostly positive feedback.

    But one of the great things about having this guideline is that it cannot mandate code, but instead, it is going to enforce and represent some best practices for indoor air quality, and it's going to fill in some of those gaps. And I think that was some of the things that Hoy and others at the beginning, back in 2015, wanted to address. 62.1 is purely just a minimum. Many municipalities and jurisdictions, not just here in North America but all throughout the world, use 62.1 as a minimum standard for ventilation.

    Again, as we mentioned, there's much more things that contribute to indoor quality than just your ventilation. So this guideline was to address all of those gaps. And it's so important to understand, again, all those contributors, the building envelope, everything from forest fires and whatnot, that can get entrained into your system and what are some better practices rather than just going with the code minimum and checking that off your list.

    So I think it'll be a great tool for a lot of practitioners, both designers, owners, industrial hygienists, and even people who are trying to troubleshoot, "How could I make my building operate better knowing that I have these circumstances with the outdoor air or even developing problems within the enclosed building?" Speaking of all of that, I had the advisory public review. You had to handle all the actual public reviews. How many public reviews did 42P go through, and what was it like addressing all those comments?

    Tina Brueckner:

    Well, we went through four public reviews, and I'm happy to say that we published with no unresolved comments, which is lovely. We had 70 comments overall, some of which were a lot more involved, and a lot of great suggestions from a lot of folks.

    And the one thing I wanted to mention is that because we had so many good suggestions from so many comments, some of which we were not completely able to pull into the document, so I'm happy to say that Guideline 42 is on continuous maintenance, right along with Standard 62.1. So it's about a three-year cycle. We will make sure that future additions bring in a lot of those comments, and we're always looking for volunteers to help us improve the document. So that's one of the big pieces. Glad to say that we're not done. We want to getting better.

    Jennifer Isenbeck:

    And I was going to say finding out all, reviewing all the citations, the research, that’s no easy task. And one great thing too about the continuous maintenance is that it will obviously continuously be updated with any new research and activities that are found within the industry, not just ASHRAE, but other organizations and that we can have that contributed to the guideline in the future.

    Tina Brueckner:

    Absolutely. And as we went through this process, several things had happened that made it a little more of a challenge, like a pandemic, and that gave us the opportunity to actually even put more information, which we know even more research is being done. And we made sure that the information that we did put in this document is not just hearsay, it is based in fact, based in research. And we know that because of the pandemic giving a lot more visibility to the issues of indoor air environments that there's going to be even more information to pull into the document. So that's one thing that I think was pretty exciting about putting it together, and it's not done.

    Jennifer Isenbeck:

    Yeah, I remember researching some of those facts myself because, again, there's a lot of hearsay events, and one of them is again about bathrooms and flushing toilets and things like that. And a lot of people take snippets of what they hear in the news or what they've read in an article or who knows where they found it. But when you actually go and read the actual research or the article, there's a whole lot more going on than a pandemic being spread by, I hate to say it, flushing toilets.

    There was actually no ventilation, or the only ventilation they had was opening windows. And anyway, so that was an interesting research that I felt like we had to be detectives and debunking either something that was being presented as fact or something that was hearsay. And so I'm very proud to say that your crew has done its research and has made sure that all those references are cited and placed in the document.

    Tina Brueckner:

    So while you were working on the guideline, Jen, what was your favorite part to contribute to?

    Jennifer Isenbeck:

    At that time, when I was working on the guideline, I was the facilities director for a private university, so I had all kinds of different anecdotes that I could share. And in particular, I spent a lot of time working on the operations and maintenance component of the guideline. Everything from green cleaning to DCV, that's demand control ventilation for those of you, and how sadly it's inappropriately applied in some of our designs and operations, as well as the pandemic did happen while I was facilities director, I had to put what ASHRAE was saying, what design practitioners were doing since 62.1 was developed into practice during those, that COVID time.

    And I think it was the combination of working on the guideline, my experience and my understanding as well as access to certain ASHRAE individuals who were experts in indoor air quality that I was able to put together the operations and return back to school plan. But what I realized if we looked at every one of my buildings on campus, if we brought the data, the outside airflow back to the 62.1 values, which were typically developed from the ventilation rate procedure, in most cases, we met or exceeded the required requirements for indoor ventilation during COVID times. In addition, of course, we had to go into the operations of ensuring that the outside air dampers were working, modulating return air dampers if we were able to.

    But then also using it as a teaching experience for myself and my employees at the time, and even faculty because they wanted reassurance that themselves and the students were safe on campus. And so it was kind of the culmination of my involvement with the guideline and 62.1 that really to me helped the success of returning back to work. Additionally, I oversaw the housekeeping or environmental services staff, and I really learned a lot from them, not just during the pandemic times, but again on their practices and what we should be doing with building ventilation systems, how we need to be running ventilation, particularly at nights and early mornings when they are doing their cleaning duties so we can at least get the, if they're using any kind of chemicals or they're stirring up dust, at least we can get that air moving and through the building.

    So I had a lot of fun kind of putting my experiences and trying to interlace them into the document as well as I did have an air quality issue, and working with a hygienist, we actually were able to make the adjustments necessary. And again, it hadn't been for things like this that I wouldn't have known the right steps to do.

    One thing, though, we wanted to bring alert to is that the conditions of indoor quality vary throughout the world. And even here in North America, there are still a lot of facilities and buildings that don't have appropriate air quality. What have you seen or experienced yourself, or maybe something you learned when you were working on the guideline, Tina?

    Tina Brueckner:

    I was going to kind of go along that same line. One of the things that I was surprised to learn, again, it's through the research that folks are doing, is that even in North America and major economies, there's such a disparaging effect of indoor air quality and environmental quality. Meaning specifically more than 40% of Americans are living in areas where there's an ozone or particulate issue. And I really didn't understand that or hadn't been exposed to it prior to Guideline 42 and some of the work that Standard 62.1 has done as well.

    Jennifer Isenbeck:

    Exactly. And elsewhere in the world. And this was another interesting component of the guideline that I have to give credit to folks like Chandra Sekhar, Bill Bahnfleth, and Wayne Thomann, that they gave us some experience and understanding elsewhere in the world, there's poor outdoor air quality, so now you're not really ventilating with your outdoor.

    The World Health Organization reports that 92% of the world population lives in areas that exceed the guideline upper limits for air pollution. This exposure to ambient air pollution results in an estimated 4.2 million deaths. And when you think about the disparity between economies and our socioeconomics is this is a worldwide problem, and whatever we can do to improve indoor air quality or, as in this guideline, enhance indoor air quality, I think it would be extremely beneficial.

    Tina Brueckner:

    So, Jen, I know you spent some time as the chair of Standard 62.1, and I'm guessing you had maybe heard from folks why 62.1 didn't do more for the pandemic. Do you have any sort of response to that?

    Jennifer Isenbeck:

    Oh, of course. It was something that I think, well, you were on the committee as well. It was something that we all wanted to tackle. It was just a challenge. Number one is, again, we're the minimum standard, but again, you would think that a pandemic, a worldwide pandemic, would push us faster. But unfortunately, as a ANSI/ASHRAE standard, there are certain protocols that must be put in place, which means it's the consensus standard, and things must go out for publication. It must seek feedback.

    We need to resolve comments, resolve objectors if we don't have consensus amongst the committee, which is a variety of backgrounds and industries, and in times, their own intentions that we can't get things changed fast enough. So I believe the White House, the Office of Technology reached out to ASHRAE, in particular, several folks within ASHRAE. ASHRAE Standard 241P, Control of Infectious Aerosols, came to fruition. It was chaired by past President Dr. Bill Bahnfleth, and we could say, as far as a standard, it was published at warp speed.

    But in order to do this, it didn't necessarily follow all the publication requirements of ANSI. However, this was a very important standard in addition to being a request from the White House and definitely from our community, but it also gave us various modes of how to understand what is equivalent clean air. And now, within our own 62.1, perhaps in the future, we'll be looking at equivalent clean air as well as how to implement minimum filtration standards. So, for instance, 62.1 only talks about filtration if the ambient or the outdoor air quality is above a certain level.

    Now, we can look at what kind of filtration might be needed for circulation air. So Standard 241, part of its premise is to lay the groundwork to improve 62.1 and various other standards so we can address some of the elements that are within our control of these minimum standards. But all together, as an industry, we are going to be addressing public health. And I really think 241 was a great advancement for ASHRAE, and it speaks highly of the volunteers, the very dedicated volunteers, because, again, they did it on their own time.

    And it also speaks volumes for ASHRAE staff, who also dedicated many hours overnight all day in order to move at this type of speed. I'm very proud of those members. I can honestly say I did not have the time to give like those members did. So again, I appreciate every one of them for putting this document together. I wanted to commend Brendon Burley and the other ASHRAE members who have been persistent in their collaboration and the communication of some of these very important elements of indoor air quality. Also, elements of indoor environmental quality.

    And it's not without all this collaboration and our work with the industry, with our federal government, with other agencies worldwide, that we are going to make a contribution to our health for our indoor standards as well as potentially policy that could be implemented here in North America as well as the rest of the world.

    So, Tina, tell me about some of the other elements or contributions to Guideline 42 that helped augment the information provided to its audience.

    Tina Brueckner:

    Some additional things that I was particularly proud of as we were putting together Guideline 42 and helping people go above and beyond the code minimum, as we've talked about with Standard 62.1, we were able to do a few things that you can't do in an ANSI standard, like for instance, specifically, I'm going to reference our appendices. We've got some great case studies that give examples and real how to's on how to use IAQ procedure, which is not commonly used today for the design professionals. And we have heard people say that it's really hard to use, so we want to give some examples of places it's worked and worked well.

    Another area that we were able to address and really add to some material was the environmental health components related to enhancing the air quality. A lot of times, we can't put those type of pieces of information in a standard. And so this was a great place to add that additional material for the audience that we've been talking about between the owners, the designers, and the IAQ professionals.

    Jennifer Isenbeck:

    Yes, that's interesting because, again, sometimes people say that ASHRAE 90.1 and 62.1 are in conflict with one another as it pertains to energy. However, as you mentioned in the case studies and some of the further explanation, we're able to kind of see how two standards can collaborate and work together. One example I'm thinking of is the—just a better example of how energy recovery ventilation works, but even more importantly, one of the more contentious issues was humidity control. And living in Florida, I can tell you that humidity control is always of paramount consideration in our design and, again, where energy targets are to be met.

    Sadly, there's a lot of circumstances we have to dehumidify and then in spaces reheat. But the informative appendix about humidity and indoor air quality helps kind of put a little context, at least for how we operate down here in the South, but also in other parts of the world, such as the Philippines and areas where humidity control is very important. And ultimately, the worst thing you can do, and I hate to say it is some of the school districts or other entities that turn off their air conditioning over the summer when the buildings are not occupied.

    And unfortunately, it makes very drastic effects and unfortunate cleanups when they return back in August and realize that not controlling the building's pressurization, humidity, and even if doors or windows were open inadvertently what that can do to a building and especially the buildings that our children attend. So some of these appendixes and elements can kind of go a little bit more in depth, and why perhaps some of these requirements are now making it into our code minimum standards. But they are also very important that we look at how buildings are operating throughout the year.

    As I alluded to earlier, many designers, owners, operators, contractors, there's some misconceptions about 62.1 that, unfortunately, can get carried away. And one of those is how to mandate or measure or control based off of carbon dioxide. I think most of us in our industry know carbon dioxide is not lethal. Well, at least lethal in the levels that we would see day to day. And even OSHA has increased its limits to over 5,000 parts per million. And some folks, particularly in industries where they're working industrial facilities, they might even experience higher levels. But not everyone reads the user manual for 62.1 and understands the premise between demand control ventilation.

    And furthermore with 90.1 mandating DCV, which I heard was another contradiction because those mandates came out during the pandemic. But the guideline really goes into an in-depth explanation of controlling off of carbon dioxide. How demand control ventilation should work. But more importantly, one of the reasons we measure off of carbon dioxide is it's a readily available sensor that's affordable. It does show a demonstration of human respiration rate, and in some cases, it is a good identifier of what kind of indoor air quality, but it's not the only identifier.

    And there's been many position papers and documents talking about this. But one thing about this guideline is it does put it in simple terms and talks about how you can effectively ventilate and what are some of the ways to do this, what are some things to measure, such as we talked about the IAQP and sensors. And ultimately, I think it can help lead to a path of more informed decisions on if your building has good, bad, or enhanced indoor air quality.

    Tina Brueckner:

    And I would say, Jen, that in addition to that, I think that's some areas that can be built on for Guideline 42 as more and more work is being done around filtration, sensors, control mechanisms, all of that. And we're getting a lot of good ideas. Again, I want to make a plug for additional volunteers to help us, but I think those are some other areas that Guideline 42 can really start building on.

    Jennifer Isenbeck:

    Thank you, Tina. And I would like to just give a plug for any of those who care about indoor air quality or are interested in other ASHRAE standards or technical resources that it is a great place to find your information and volunteer and become a committee member. We always have room for more.

    Tina Brueckner:

    Well, thank you, Jennifer, for joining me today and talking through this. And I'm Tina Brueckner. Thank you for folks that are listening to ASHRAE Journal Podcast, episode 35.

    ASHRAE Journal:

    The ASHRAE Journal Podcast team is editor, Drew Champlin; managing editor, Kelly Barraza; associate editor, Tani Palefski; technical editor, Rebecca Matyasovski; assistant editor, Sara Omer; and assistant editor, Alison Hambrick. Copyright ASHRAE. The views expressed in this podcast are those of individuals only and not of ASHRAE, its sponsors, or advertisers. Please refer to for the full disclaimer.