Okay everyone, well I have 2 p.m. Eastern time. You should be able to hear me speaking at this point. If you're logged in, you have reached the HVAC and COVID-19 webinar. This is an education on the indoor air virus relationship. So you may notice that this will be a different type of webinar that we usually host here at RetroTech. Instead of the standard structured webinar that we talk about where we talk about air tightness testing and things like that, this will be more of a free flow discussion. We have three panelists that are on with us today to talk about this who are more experts than I am in this topic. So we're basically just using our platform to get this information to you. So that being said, you notice we have this disclaimer here. So the views, opinions, and content expressed in this presentation by the guests and hosts do not necessarily reflect the views, opinions, or advice, or policies of World of RetroTech. So I had to get that out there at the beginning. So Nate Adams and I were talking before, we were actually going to do a webinar on a totally different topic. And as this coronavirus issue got worse and worse, faster and faster, we realized there was some questionable information being pushed around out there to HVAC techs and homeowners. And we realized, you know, there's a lot we could probably do to be helpful here, to maybe help clear the air. So that's what we're trying to do today. So we're using our platform. Nate's put together a really nice presentation that really dives deep into some of the research that's out there. And one other thing that I want to stress here is that there is nothing in this webinar that will replace any CDC guidelines. Please, please, please follow the CDC guidelines, keep those hands washed, keep surfaces disinfected, stay away from large groups of people that's still highly, highly important. The information that we're giving you here are some extra steps you can take at home while you're in quarantine to improve the air quality of your home. And a good way that Nate put it earlier, this is likely to help, unlikely to hurt. So with that being said, we'll go ahead and get going. I'll introduce everybody here. For anybody that's new here, my name's Sam Myers. I serve as an in-house building science consultant for RetroTech, RetroTech manufacturers, air tightness tools. And so as we get into air tightness testing, we get into indoor air quality. So it's a hard topic for us to miss. So that's who I am. And I'll be moderating this presentation today. And on here with us is Mr. Nate Adams. We've actually had Nate on our webinar series before to talk about his HVAC 2.0 program. But the big reason why Nate is here today, one of the big things that he does is he fixes sick, inefficient, and uncomfortable houses. And what sets him apart from other contractors is that he actually tracks air quality results on projects and probably has more air quality monitors out in the field than anybody else out there today. So he's constantly seeing what works and what doesn't. And he is doing a ton of research on this stuff too, trying out new products and has his finger on the pulse of the IEQ field, probably more than anyone else out there that's getting that real world experience. And so that's why I'm excited to have him to come talk about this topic with us. He's also the author of the Home Comfort book, which is the best introduction out there to this topic. And he also has his HVAC 2.0 program that's educating HVAC contractors on this stuff as well. And another thing about Nate is his network. This guy knows just about everybody. He'll try to tell you that he's just some guy from Ohio, but don't listen to that. No, he knows what he's talking about. And that brings me to my next guest. We have with this Dr. Shelley Miller from the University of Colorado at Boulder. You can see here she has an extensive resume, but some of her research projects include bio aerosol characterization and control, characterizing ultra fine particles that penetrate into mechanically ventilated buildings and reducing exposure to infectious diseases through engineering controls. So she's done some extensive research on this stuff. And we're all eager to hear your view on this, Dr. Miller. And thank you for joining us today. And last but not least, we have Mr. Michael Housh.  Michael Housh is a third generation owner of a family owned company that started back in the 50s. He specializes in residential geothermal and home comfort. And he's a well known industry expert. The good thing about him is that he actually takes a lot of time to answer people's questions, especially new people starting out in the field and dedicates a lot of his time to training in that regard. So an all around HVAC rock star pretty much. So we're happy to have him on too. So thanks, Michael. So with that introduction, Nate Adams went ahead and put together, spent all week pretty much putting this presentation together. And he's going to kick our discussion off here. So Nate, you are welcome to go ahead and take control. I'll actually kick this over to you. Can you set up? I actually haven't control still right now. Okay, perfect. Can you open the presentation? I will. And then click view and present, please. Thank you. Awesome. Sometimes our webinar platform does cause a few seconds to lag there, but it looks like we're up. Nate, are you able to move through? Well, let's find out. Awesome. There we are. Okay, so let's get rolling. Okay. So welcome everybody. And there's a lot of information to cover here, but I'm very, very thankful to have Dr. Miller and Michael House here. Because I want to stay on the straight and narrow as much as possible, technically. So I'm leaning on those two, if I say something too strongly to pull me back on that. So one of the curses of life is people who don't know much are typically very, very confident. And then people who know a lot are much less confident, which we'll be actually talking about a little bit later. But this is what we're going to cover as we go through this. So we're going to start with key takeaways. So if you can only be here for a few minutes, you're going to get the critical points. You just won't necessarily understand why those points are what they are. Then we're going to talk about questionable products, because there's a lot of stuff being slung out there right now. And that was very frustrating to Sam and I. That was kind of what started this. And then Michael was also very annoyed. And it kind of started this whole process. And then Dr. Miller, I asked her if she'd be gained for coming on just to provide good technical backup. And I was very thankful that she said yes. So we'll go through questionable products. Then we're going to talk about the science, because the three main things that we have some idea that are helpful with dealing with viruses are humidity controlled, good filtration, and fresh air.  So we're going to give you temporary and permanent fixes and also why those work more as much as we think they do. Okay, this is a really important point. So I view myself as a doctor for houses. And the doctor's oath is first, do no harm. And this is one of the things that was driving us crazy. It's UV lights in particular are being sold as curals. And they're not. And they can actually cause some fairly bad things. So it's very important that in anything that we recommend, we are adhering to first, do no harm. And another thing to note, what we may be talking about, it's possible they will be placebo. So this is not hard and fast, we don't know if it's going to affect you and your family specifically. But we do know that what we're going to talk about are these are best practices with a lot of research behind them. And Kaiser, I see your question of what bad thing can you be cause we'll get to that. And that's going to be mainly Shelley talking about that because I am not an expert on this at all. And that's another thing I want to add to please use the Q&A box if you have any questions. And one thing I didn't mention to yes, we're still going to give BPI credits for this. So if you want a BPI CEU, you can give us your name and number on that too. But we're going to take questions every 30 minutes. We've got an hour and a half dedicated to this and it may run over more than that. And any of our panelists, if you have to leave before that, that's fine. We appreciate you being on. But about every 30 minutes we'll stop and we'll dig through that Q&A box and then we'll keep tracking. So sorry, Nate, keep going. No worries. And if I see a question in the box that I think should be addressed, I'll tackle it. So I'm thankful we're running this the way that we are where I'm controlling your screen because I can actually see what's going on. All right. So moving on, key takeaways. There's four different things you want to take away here. First, how is the virus transferred? And then second, third and fourth, how do humidity filtration and fresh air come on? Or how do they apply here? So transfer is pretty simple. Hopefully everyone has seen this news at this point. It's transferred through sneezing and cough.  And that is how it appears to be transferred. When it comes to humidity, if you want to reduce the transfer and spread of viruses, you want to keep your relative humidity preferably between 30 and 50 percent. You can push a little higher, but when you push a whole lot higher than that, there's other risk factors that come into play and we'll talk about those later. Filtration, you want to be using Merve 11 or higher filters. Really, you should be using the Merve 13 or higher. We'll get to all of that. And then fresh air, carbon dioxide is the most common proxy for fresh air in a building. And outdoor usually runs four to five hundred parts per million. That's the PPM. And we want to do what we can to stay between 600 and 800. If you can get lower, great, but 600 to 800 is a good target. So, and that's it for the takeaways. Questionable products. This is a cartoon from my book, The Home Comfort Book, which not to pitch it at all, but a number of the chapters, four out of six chapters are free downloads. So, if you want to learn more about the building science, that can be helpful. This cartoon came out of it though, because we watch this happen all the time. We see people taking the simple but wrong path. Oh, this one thing will fix it all. This is the silver bullet. With most things in life, there are no silver bullets. There's a whole bunch of silver BBs, if anything. So, the correct path tends to be complex, but correct.  And then you can increase the likelihood that what you are doing is A, likely to work, and B, unlikely to harm you. And here's actually this. This is something that just takes me off. If you're looking for why this webinar is happening, this meme is one of the reasons. Behold the cure for a low average ticket during the Corona pandemic. So, I work in the HVAC industry. So does Housh. Housh owns a decent sized contracting concern. And I purposely covered up the product that's being held up, but suffice it to say that it is a UV light. And if you think that people that are pushing this are having your best interest in mind, you know, sometimes they might, but it is not a cure all, and it actually carries some risk. So, in fact, speaking of the risk, we were talking about this in one of the groups that we run the other night. And Matt Milton, who is down in North Carolina, the exact product from this meme, the exact same one. They sent him one, and he put it in, and look what he said. I had one of these to try. I literally about killed my wife with it. She has asthma and the thing put out so much ozone, it put her in the hospital. And so she was in the hospital for two days, and she needed breathing treatments for two weeks afterwards to get the inflammation down. Is this going to happen in every case and with every product? No, absolutely not. But if I recommend a filter, the odds of it killing someone are pretty much zero, where the odds of problems with UV are substantially higher. So it doesn't meet the do no harm for the most part. And Dr. Milder is going to dig into what the good applications of this technology are because they are there. But they're not particularly common, if at all, in the residential space. This was another meme that drove me nuts, ending COVID-19 one commission check at a time. So this is how it's viewed by some people, not everyone. So one thing that we have learned through developing the HVAC 2.0 program is there are a whole lot of HVAC contractors out there who really care. They like to do good work. They want to do the best thing for you. Obviously, they need to stay in business. But man, it's dangerous. Sometimes the things that can be recommended. And it's really important to align incentives so that what they want and what you want are the same thing. And that really requires diagnostics as we'll get to you later. I was going to add real quick. I also think it's important to denote that some contractors may just be ignorant from the fact. And so that's another important part of why we wanted to do this. And so not trying to lump everybody into the evil sales tactics category, although there are some that fit there as well. Yep. Yeah. In general, what's that great line? Never attribute to malice what incompetence can explain or just its lack of knowledge, which is fine. And to be frank, the reason I don't know much about UV lights is I dug into them a couple years ago and I found nothing that smelled right to me and I just abandoned it. So that's the reason I don't know much about it. I just didn't find any literature that was satisfying to me. And to your point, Haush, this is the Dunning-Kruger effect. And I don't know if anybody here has seen this. Hopefully you have. This is a really critical thing to understand. So you've got conviction here and knowledge on the other axis. And when you start out, you feel like, woohoo, I know it all. And you're feeling great about it. And then you start digging. And you start questioning whether you know very much. And then you end up in insecure canyon down here. Now, I spent years down there digging into all this stuff and trying to understand air quality and how complex it is. And I mean, the reason that Dr. Miller is on here today is that I prevented her asking her questions a while ago and I've ended up knowing most of the air quality researchers in the country because there's not that many. And once you get to know a few, you kind of end up getting to know all of them to some degree. So climbing out of insecure canyon is grown up mountain here. I love all of this. And so the reason that Dr. Miller is on here is I am climbing this mountain and I recognize that I do not know at all. And so it's very important to state that. And a lot of people you're going to work with, they may be up here on Child's Hill. And hopefully this webinar today, if you are down in insecure canyon will help pull you up somewhat from there. Now when it comes to a lot of the products you're going to see pushed out there as a cure all and there's a number of ones and I'm not going to dig into all of them. But if somebody comes to you and they're like, Oh, this will solve all your problems. Just one thing. Wham, bam. Thank you, ma'am. It's done. Please apply the precautionary principle. And this can be somewhat disputed, but it's the safe measure. So if there are issues of potential harm and there's not extensive scientific knowledge, this is emphasizing caution, pausing and reviewing. So just take your time. We're going to show you a number of technologies that are pretty well understood already and look like they can actually be effective. If you want some further learning, there's some great homeowner-oriented stuff here and we are tailoring this entire webinar to a homeowner level rather than a contractor level. They oftentimes cross quite a bit. But if you are here as a homeowner, this is meant for you. And this particular series, Homechem, is a great resource to look at. So this is on the Home Performance channel on YouTube. This is Corbett Lunsford channel. Take a look at that. There's just lots of lots of information at a homeowner level. Yeah. And Corbett also has a TV show that dives into some of this stuff too. Yes. So yeah, he's an all-around good resource for this type of thing. Exactly. I would trust anything he puts out. Yeah, and that's important. Alison Bales would be another good author in this space as well. And by the way, at the end, we'll be talking about resources and the best thing to do, frankly, is going to be to join a couple of groups because if you're going to get questions answered and you're going to have multiple things, it's going to be ideal to be able to discuss them together. So at the very end, we'll talk about that. All right. How should you show me this? This is an EPA page about ozone generators. And I love what it says there. There's a large body of written material on ozone and the use of ozone indoors. However, much of this material makes claims or draws conclusions without substantiation and silent science. This basically states why I stopped digging. But then I paying Dr. Miller and she's like, well, there are applications where it's a good idea. And she'll be getting to that in just one minute. So I think this is my last slide before I turn it over to Shelly. So Robert Bean is a good friend of mine and he has forgotten more about indoor environmental quality and indoor air quality than I will ever know. And I love what he said here. Anytime you read unique technology or proprietary system or certified by ASHRAE or developed by NASA, your BS meters need to be activated. He doesn't mean building science. Independent third-party testing, where an unbiased, non-conflict of interest research team of peer-recognized scientists is doing this study, cuts out most of the S&M, sales and marketing for smoke and mirrors, crapola. So I asked him if I could share that and that'd be great. His website, by the way, is healthyheating.com. If you want to dig into stuff, I can't tell you how deep that well of knowledge is. So have fun. We'll see you in two years. And this is the consensus that I have heard is that products that are good in commercial and industrial applications with strict engineering are not necessarily good for residential applications, particularly without that engineering. Okay. And now I'm going to turn it over to Shelly to talk about where UV is useful because lots of people are asking. Great. Thank you. I started this research in 2000 with funding from the CDC and NIOSH. We were looking at the use of UV lamps for control of airborne infectious disease, namely that the rise in tuberculosis. And UV lamps come in many different forms, but the kind that we use for infectious disease transmission is UVGI, which centers the wavelength emitted at 254 nanometers. We know that's germicidal. What I want to point out on this slide is the upper left figure shows a red circle around 185, which is the wavelength at which oxygen is changed into ozone. And so if you want to generate ozone, you buy a 185 nanometer lamp. If you want to do germicidal UV, you buy a 254 nanometer lamp, which is also coated to make sure that any little bits of 185 do not come out of it. We have thoroughly tested all of UV lamps for our purposes and none of them generate ozone. So my concern with the product that Nate mentioned earlier for the that damaged the lungs of the family that installed it was that it was probably a 185 nanometer lamp. You can do the next slide. Oh, thank you. Or can I? There we go. A quick diagram showing what happens when you irradiate a germ with UVC. It inactivates the germ or the bacteria of the virus, so it can't replicate by damaging its DNA. And you can see the graph on the lower right is the bioactive wavelengths at which this happens. The peak is about 265. 254 is reasonable to do DNA in activation. Next slide. So we've studied the appropriate uses of these germicidal lamps, and they're mainly for industrial facilities like hospitals, jails, homeless shelters where there are severe overcrowding or potentially unsuspected cases of infection. We use it in upper room air systems where the UV is strictly in the upper zone because if it is in the occupied zone, it can damage the skin and eyes of people who are overexposed. You can also put it in the ventilation ducting, but you have to make sure that the airflow past the UV lights is slow enough so that it can work. Sometimes they're used on cooling coils to keep them clean. They do some have some benefits there, but it's not a magic bullet. And then right now we've seen very good effects of using a high wattage robot to clean hospital rooms where all the people leave, you wheel these in, you turn them on for maybe an hour, and then you leave and they have helped with cleaning the room. And this has been tested in CDC trials to show that it is effective. Next slide. Here's a picture of UV hung at a homeless shelter, and this is the upper room system where just the UV radiation is in the upper zone only, and the people in the lower zone are not exposed to the radiation. Next slide. And so we like to think about doing upper room air when we need to add additional air changes, but we don't have the money to retrofit the HVAC, like hospital treatment rooms, or to reduce the risk of infections. Next slide. Yep, next one. We put them in rooms where there is infectious aerosol being generated, so in isolation rooms or rooms in indoor air pool facilities. We've done that here in Boulder as a matter of fact. Next slide. And then crowded environments. Okay, we're done. Next slide. I helped the CDC write a design guide for upper room UV. Here's a picture of the design guide. You can just click through these real quickly to show you that it's complicated. You have to be careful when you do all of this. You need to install enough fixtures. You need to put them in the right place. You need to put in the right irradiance. You need to keep the temperature and relative humidity in the right place. So this is not for just novices to do. It is for professionals and engineers to design and implement and maintain. Next slide. You also need to maintain the guide that lamps. You have to burn them in, you have to clean them, you have to be careful when you replace them, and you have to know how to tell if the device is not working. So this is why we recommend that these are installed by professionals and that they're used in places where people can regularly maintain them. It's not great for homes because that is typically not available for homeowners. All right, I'm done, Nate. Thank you, Shelley. I really appreciate it. Yeah, so one question for the group here. So from the typical homeowner's perspective, the layman, when you hear ozone, you think of this stuff that's up in the upper atmosphere, that's a good thing. And so when it's exposed to us in our homes, why is that so bad? So in the upper atmosphere, the UV helps absorb the radiation from the sun that's harmful to us on earth. Here on earth, the UV is a powerful oxidant that damages your lungs. It's like breathing in chlorine. You know, it's very powerful oxidant. So that is why we don't want it near the earth, but up in the stratosphere, we don't mind it because it protects us from the radiation from the sun. Excellent, thank you. Shelley, Eric Kaiser is asking, do you have any info on far UVC lighting? And you might as well talk to any residential studies that are out there. No, I don't have a lot of information on far UV lighting. There are some niche developments in the germicidal field with using xenon and other LEDs, for example, but there has not been enough development or testing that I know of to warrant using them. And what studies have you read that apply to residential? I have, I'm aware of one study that applied to residential where this device was developed, where the air was taken out of the home and circulated past a UV light and then put back in a home. So like an in-depth recirculating system. And some indications that it did improve some small measures of asthma in the household, but it was a pilot study and I have that paper available if anyone would like to see it. Great, and that's about all that you've read, correct? Yeah, I haven't seen much else in the way of household applications and I haven't worked on any myself. Okay, that's helpful. That's what we know. And that was the main thing that I wanted to have somebody who knows way more than me have to talk about. We don't know much about the residential space. So these are the two rules that have ended up kind of falling out when it comes to looking at whatever product you want. So two simple rules. First, ask for independent studies and we just heard that there aren't many in the residential space. And the second one is don't add stuff to air except for water. We are not saying that these things can't work and there aren't applications and so forth, but we're just saying be careful. And pay attention. Are the people that you are talking to see if you can figure out where they are on Dunning Kruger? Did they just learn or are they pretty well down the curve and now they understand? So UV might be an option at some point, but it's not a first line thing. And I guess one common takeaway that I took away from Dr. Miller's presentation was that you can't just slap something in and hope for the best. It's just a lot more complicated than that. So that's why it just needs to be taken more seriously. Yep. Actually, there's a couple of other questions coming in here that we probably should touch on. So Tom Weigel's here. He worked with Dike and he asked, do you have any comments about the oxidizers that are generated by PCO type air purifiers and would they have the same damaging effect on human lung tissue as ozone would have? So this is Shelley. I haven't done too much work on PCO, but typically the UV light is used to activate a catalyst, which then oxidizes anything that's deposited on the catalyst. So it's an enclosed system. So you won't be exposed to the UV and then it depends on what has been oxidized and what's the transformation that happens upon oxidation. Okay. All right. Well, we'll just keep moving then and Shelley, please hop in as I'm going through this other stuff because hopefully I did a decent job on the research, but if you see a hole in my research, please speak up. And same thing, Michael, if you see any holes, anything I'm saying. All right. So let's talk about the science. We're going to dig into this and that's humidity, filtration and fresh air. Oh, I got to click the right thing. Come on, honey. Is it going to let me switch? Hey, Sam, can you go next slide? Yes. There we go. All right. This was the best discussion that I saw of how things are transferred. And basically back as early as 1945, we figured out that a sneeze or a cough can, they're likely the source of the spread of viruses and bacteria. And why is it not liking me? Sam looks like I'm going to be saying next slide, buddy. Okay. That's all right. I don't know why it worked before and it stopped now. Okay. So I don't know if anybody here has seen the pictures that came from this study, but it was pretty funny. The shadow graphs, they've got a guy sneezing and then you can see the things flying through the air. So I thought this one was interesting. Next slide. Oh, good. It's letting me again. So I watched a great video by Dr. Lindsay Marr. She is at Virginia Tech, if memory serves. And the presentation was from 2016, I think. And what she talked about was an engineering approach to how viruses spread. And I like that because while I may not be a professionally trained engineer, that tends to be more of my way of thinking. So you figure out what's the source of emissions? How does it transport when it's in the air or wherever it is? How does it get transformed? Then how does it get transported again to be exposure? So I thought this was a nice thing. And here's that shadow graph picture I was mentioning. I've seen this picture for years. And I think it came out of that study. By the way, Sam, can you see the Allen Gates raised hand pop up? Or is that just on my screen? I think I saw that earlier. Okay. As long as it's not showing anymore. Yeah. All right. Good. I can't see your screen. So I don't know. Here we go. Okay. So Lindsay the other night tweeted this out. And this was a study that was just published in the New England Journal of Medicine. And I'm going to zoom in on this later. But the key thing is it looks like COVID-19 or SARS-CoV-2. It is airborne. So this was a study that showed how well it survived in the air and then on various surfaces. So a little bit tighter, like I said. We'll come back to that in a little bit. But this is the latest thing that just came out a couple days ago. There are studies coming out like crazy. I don't think it will change most of the conclusions of this presentation. It may not change any of them. But do pay attention to what's going on out there. Okay. Sourcer droplets, sneezing, coughing, breathing is kind of a hard one. And the important thing to note is most of the droplets do settle out near the creator. So that has been found repeatedly. But we do need to pay attention to source control. So prevent those droplets from getting into the air, at least when coughing or sneezing. Like I said, tough to stop breathing. Okay. Cough into your elbow. Or I saw someone recommend coughing to a tissue because, you know, your elbow is going to get pretty dirty over time. And if you cough into a tissue or something, you can throw it away. Or if you use a rag, you can put it in the wash. Wash your hands a lot. Disinfect surfaces frequently. Follow expert advice. So this should all look really, really familiar. We are not trying to go against anything that's out there. But on the HVAC side, this is a wild stat. Brian Baker, who sadly passed away of cancer about a year and a half ago, he did the math and figured out that we breathe 3,000 gallons a day of air. And we do 90% of that indoors. And now thanks to sheltering in place, most of it is inside of our houses. So knowing that this virus is airborne and that we're spending a lot of time in homes, it seemed like it made sense to dig into this because this is the constructive side as opposed to getting too deep into UV, which can be tricky. So this is my hypothesis, basically. Humidity control and filtration can help reduce virus spread. And I really should mention fresh air as well. So let's examine the hypothesis so that you understand where I came up with this. And I've been digging into air quality now since 2014, 2013. I had an air advice monitor and that taught me a bunch and then dug into a bunch of the low cost monitors now. In fact, I don't know if you can see behind me. I have 11 in my office present. So I've dug into this quite a bit, so hopefully I understand it well enough to explain it. This is a simple graphic from the EPA and it gives you an idea of how big various things are. So I really like that human hair is 50 to 70 microns or nanometers. Well, micrometers, micrometers, excuse me. And so that gives you an idea of size. And then we step down to PM 10 and PM 2.5 and even smaller. So this gives you an idea of the scale of the particles we're talking about. And this is why this matters. Aerosol size, so it says defined transport. Basically, this is viruses tend to be suspended in droplets when we sneeze or cough. The viruses themselves are incredibly small.  They're very, very small. When they are in a droplet, they're typically larger. So in this instance, it's saying 0.5. But let's talk about what that means. So PM 10 means particulate matter below 10 microns. PM 2.5 is all particles below 2.5 microns. And PM 1, hey look, a pattern. This all makes sense. Whatever the number is, it's that size and smaller. And let's just briefly look at what happens to these particles because this matters if we want to capture them. So PM 25, which is very big, frankly. I mean, that's half the size of a hair. That's going to land on the surface. PM 10 is small enough that we can inhale. So we'll end up in our mouth. PM 2.5 is small enough that it will go into our lungs, or it's very capable of going into our lungs. And PM 1 is small enough, not only will it get into our lungs, but it's so small it will go through our lungs and directly into our bloodstream. So if there's something that is bad and small, it goes right into our blood. And that happens to be viruses. Okay, how long does it take to settle out? These are really approximate. I'm just trying to give a basic idea of what's going on. It's going to depend on all kinds of factors. But the larger particles are going to settle out in minutes, maybe even seconds. PM 10 might take hours. It might take minutes. PM 2.5 is going to take hours or days if there are air flows, it may stay suspended. And PM 1 is from what I'm told by a number of researchers incredibly difficult to deal with, because it never settles. The very small stuff electrostatic can help with and pull a lot of it out of the air. But PM 1 is just large enough that electrostatic activity doesn't take it out of the air. And it's also small enough that it stays suspended. So those are the problematic sizes. And then we'll talk about how easy is the filter. And don't worry, I'll show you a chart of what these MIRVs mean. House, do you remember what MIRV stands for? I don't remember. Man, you're putting me on the spot here. No, me neither. Don't worry about it. Suffice to say MIRV, you know, he put on game shows and stuff. Yeah, I mean, I definitely just read about it and just drawn a blank. So good. Shelly, pop quiz, do you remember? Can you repeat the question? What does MIRV stand for with regards to filters? Oh, yeah. I got it. The guys in the comments.  Thank you, Google. Minimum efficiency reporting value. Okay, there we go. So the higher the MIRV, the better it is. So when you're talking the big particles, a MIRV 4 filter, so if you have like a really crappy fiberglass filter that's only used in residential, we joke they're good for stopping large rocks and small children. That's kind of what we're talking about in the low MIRV range. MIRV 8 is starting to get into a decent filter and the MIRV 8 will help with PM10 affair amounts that will show effectiveness in a little bit. PM2.5, you need to have MIRV 11 or higher. And PM1, you need to have MIRV 13 or higher. If you've heard of HEPA, that is MIRV 17 to 20, give or take. They're different rating systems, so they're not directly analogous. But to get to the small stuff, you need a really good filter, suffice it to say. But it's important to say that you can't just shove a high MIRV filter into just any HVAC system. No, no. And so I'm definitely coming to that point. If you just shove that in something, it will stop the flow so much that it's pretty likely to break your HVAC. Or if nothing else, take years off of its life. So you can't just put one of these in and call it good. Okay, so back to the aerosol size. This is where humidity ends up mattering. So this is again from Dr. Maher. And what she found was as relative humidity gets lower, the droplet sizes get smaller because they evaporate. And the smaller the droplet size, the harder they are to filter. So she may disagree with my interpretation here, and I'm sure I'll hear from her one way or the other. But suffice it to say the drier it is, the smaller the particles get and the harder they are to filter. And she did a study looking at influenza A in airplanes, daycares, and a health center. And she found that 70% of the particles are smaller than 2.5 micrometers or microns. So if we want to deal with the flu, or which is a virus, we need good filters because they're small. And I promised that we would zoom in on that study. So this is again from the New England Journal of Medicine. When we're done here, I will make sure that everybody gets a link to these slides so that you can click on all of these links because I made all of these live as we went. But take a look at this. This is the predicted decay. And on the bottom is COVID-1. So I pulled things off. That is SARS from back in 2003. And the top one in red is COVID-2 or COVID-19. And as you can see, it stays in the air and stays viable in the air for multiple hours. And this is the second piece of it. Shelly, you might be able to talk to this better than I do. I'm sorry to... Oh, did we lose her? Oh, she had to go. Well, so the half-life of a viable virus. So it means about after an hour, you've lost about half of the viable virus. And then that continues. So at two hours, you're down to 25%. And it keeps having as you go. So this virus can remain viable in the air for an hour pretty easily, or several hours easily too. Now back to the filtration. So to talk about what level of filter we need, when you're talking basic stuff, so you can see a Merv3 here. It deals with household dust, lint, and it will protect your HVAC. So it's also rocks and small children up in this range. When you get down here, paying attention in particular to this one in Merv13, virus carrier particles. This chart has been out there for a long time. This way predates COVID-19. So they have a decent idea that can do it. Now let's look at efficacy. And this is way too much to put on a slide, and I apologize. But I wanted to at least help people understand how filters work. So notice at the top here, we've got particle sizes, 3 to 10 microns, 1 to 3, and then 0.03, which is incredibly small, to 1 micron. And then it walks up step by step in the Mervs. Note that when we get the Merv13 with the really small stuff, it's less than 75%. So no, it's not 100% effective. But if you are running filtration constantly, if the air gets a couple passes through that filter, it's likely to come out. And then Merv11 is the bottom of what we would recommend. So with 1 to 3 microns, it's 2 thirds to 80% effective with 3 to 10, 85% effective. So this helps give you an idea of what's going on. And Merv13 is, that's the ideal, if you can do that. Merv11 at a bottom, don't go below Merv11. And the curses, most HVAC systems can't accept this. So we're going to get to how to deal with that later. And well, I guess we're going to get to it now. I forgot I had this slide in here. So for whole home applications, this is what's called a media filter. So this would get bolted onto the side of your furnace or heat pump or whatever, and provide really nice filtration. So if you can see here, I don't know if you can see the pleats in this where it goes up and down, they're very, very long. I think so primarily with media, it's surface area, right? So with the larger media, you get a lot more contact time and surface area and versus stuffing a Merv8 or Merv11 into a one inch slot. Yes. So they just try to add surface area in a smaller space and it makes it a lot more resistive to pressure. Yep. Thank you for that. Oh, and well, that's that's what I put here important. So Sam mentioned this earlier. Do not jam one of these in your current system unless it's designed to have one. It's likely to reduce the life of the system. So you can easily take five or 10 years off the life of the system by putting one of these in when it shouldn't have one. So don't just do this. Now, here's a spot solution. And it's funny, I taped this together the other day and it's actually wrong. But I worked with one of the ones that I had and I haven't built the other one yet. So a spot solution, this is called a filter fan. And it's a really simple beast. You take a standard box fan, a 20 by 20 window box fan, and you duct tape a filter of the same size onto it. So I actually have my new one. I don't know if anybody's looking at the video, but I've got one sitting right next to me because I need to make a video of making this in the next couple of days. I just didn't get to it yet. But it's pretty simple. You take a box fan and then you duct tape the filter onto it. The curse of these is going much above Merv 11 can be problematic because it just won't flow enough air. So Merv 11 may be as good as works well with these. But yeah, with that too, you definitely want to block off the sides, maybe with some rigid foam board. That way you still have a little bit of insulation on, each side of the fan.  So you want to have that sealed good around that. Correct. And so you're jumping ahead there. You can put one of these in your window to blow air in. So we'll come back to that. But in this case, you can just put it on the floor in your room and you use it like an inexpensive air cleaner. So you can build one of these for between 50 and 100 bucks. Gotcha. So you can also, and we'll get to it a little later. You can buy an IQ air or an Austin air, but those are 600 to $1,000. This is less than 100 bucks. So if you're looking to do something, this is something. And the research looks pretty decent on it like it's actually effective. Okay. So we're going to switch from filtration to humidity. This is a chart that you should really, really be familiar with. This is an ASHRAE chart. It's older. If you look at it, so we've known this stuff for a long time. Look at the data on there is 1986. So they show the optimum zone is between 40 and 60 percent relative humidity. I actually disagree. I would say 30 to 50 because it makes it, it just can reduce some other risk. So we're, we, with watching the FUBOT air quality monitors that we have about 40 of out in the field, when you break 50%, you start seeing the chemical interactions or volatile organic compounds. They start to increase. So we found if possible, keep under 50. With the viruses, you may push a little bit beyond closer to the 60, which we'll get to, but in general, 30 to 50 is the place to stay. So that's our general recommendation. But note how humidity affects all kinds of stuff. It affects bacteria. Viruses is the one that we really care about here. So the higher you can get the better. Fungi, which is mold, dust mites, respiratory infections, you know, there's all sorts of stuff going on here and then ozone. And I really like this chart, especially for home owners. It's a really good layout to show how, how everything is impacted by humidity.  That's a thermostat that has one number on it in most cases that you can adjust up or down. Yeah. And that number is temperature. But I'm sure as you've noticed, 70 degrees in your house might feel different than 70 degrees at someone else's house or at work or something like that. And there's lots of variables at play, but humidity is definitely a big one. Yep. Humidity is big. Yep. Fourth service temperatures. Even if you don't have a thermostat that shows humidity, you can get a low cost hydrometer or some type of, you know, air moisture device that can show you what's going on and whether if you need to bump that level up or down, depending on where you live. Yeah. That's a level one recommendation of 20 bucks. We just found one that works nicely and is a data logger. So we'll get to that a little later. Okay. Important note of caution when it comes to cold weather because we're just coming out of winter. I live up north. I'm in Cleveland, so we're a relatively cold climate. We're not brutally cold, but we're fairly cold. And so this is from dewpointcalculator or dpcalc.org. And note, so this is 70 degrees and 30% relative humidity. The dewpoint there is 37 degrees. And I don't want to get into this too deeply, but basically any surface that this air touches that is below 37 degrees is going to condense. And if you get enough condensation over time, it's likely to lead to mold and rot. So you can run higher humidity levels in the short term, but I wouldn't do it for more than a couple of weeks. You might be causing other issues that you have to deal with down the road. So important note. A good comparison for that is just like if you have a glass of ice water and you leave it outside on a hot humid day, it's the same thing. Yep. Yeah, exactly. When you see condensation on a ice water or lemonade or a can of beer, that means that the surface and therefore the liquid inside is below dewpoint of the air that it's in. And as soon as it warms up, you'll notice all of the condensation going away. And we want to do what we can within reason to prevent that condensation. Because if you see it, in the wintertime, if you see condensation inside your window, that is a really good sign that something's wrong. So you want to reduce the humidity levels. And in the summertime, if you get condensation on the outside of the window, you're probably keeping the space too cold. So anyway, it's not to dive too deeply into that. There's other content that I've produced that touches on that much more strongly. Okay, so back to this chart of evaporation. We want to keep that humidity level higher. So we were just talking about relative humidity. If we really want to keep the particles bigger, we actually want to keep relative humidity very, very high in the 80 to 100% range. Don't do this. You're going to cause all kinds of other trouble. But you do want to keep it as high as is practical. And then this is another way of looking at it. So I don't really understand all of the mechanics going on underneath here. I am not a scientist. But you can see the infectious concentrations versus relative humidity. When you're running very low humidity, 10% range, which can happen in northern climates, in leaky houses, you're going to get a lot more bad things happening. And this is not specific to COVID-19, by the way. This is researched several years old, but it should cross apply to a large extent. And then you can see as you go to higher relative humidities, there's less infectious concentration. And she does make a note down here, inactivation rate is lower at lower of humidities. Okay, now specific to COVID-19, this is an outdoor study. And the data is kind of blobby, as you'll see in a second. But it looks like we should get at least somewhat of a respite from COVID-19 over the summer, somewhat, because it's still propagating in some warmer countries. But hopefully it will help take the edge off of it as we flatten the curve. And if anybody has seen the article that just came out, it's called the hammer and the dance. It tells the story very nicely of how we have to tamp down the spread quickly. And then once we get it to stop spreading, we release the restrictions one by one and see what happens. And then if it starts to spread again, we have to tamp them back down again. So anyway, there's at least some hope that higher temperature and higher humidity can reduce the transmission. There's the abstract, I'm not going to go through that. These are the charts. And this is outdoor data, which is kind of a pain, because you, and this is in Celsius. So forgive me, I don't know all of the math on it, but minus 15 is probably going to be close to zero Fahrenheit. And most of the the weather that they were tracking here is between zero and 10. So we're 30 to 50 degrees, something along those lines. But the line of best fit does trend down as the temperature gets warmer. And humidity, same thing. And this matches what Dr. Mar was showing. Now, what I really don't like about this is this is relative humidity. And they also goofed up the label here that should be percentage 80, 90 and 100%. So at night, the relative humidity goes up very high. So we routinely see 80, 90, 100% relative at night. And that's probably what's tracking. But in any case, it gives some hope that as the weather warms up, this thing will get a little bit better. And just to repeat, humidity 30 to 50% is the ideal range. You can push to 60, don't push beyond 60, all sorts of bad things that happen. And this varies per climate, depending on what you need and time of year. Exactly. Yeah. So thank you, Sam. So in the wintertime, we recommend here to stay between 30 and 40. And when it gets really cold, you probably have to drop it below that. And in the summertime, we shoot for 40 to 50. So that's how that usually falls out. And thank you for the correction. It's important. Okay. This is a study from Lawrence Berkeley National Labs back in 2012 that basically found that carbon dioxide makes you dumber. That is the layman's phrase for it. Or you can say the stale air hurts mental function. So fresh air is going to be a piece of the puzzle. And I found one study that touched on this, which we'll get to in a minute. But this is important because this applies all the time. This is not just while we're trying to figure out how the heck do we flatten the curve. So take a look at the black dots here. These black dots, when you're getting low, so this is where through various tests, the test subjects were performing badly. This is at 2,500 parts per million of carbon dioxide. So that is about five times outdoor concentration. That may sound really high, but it's quite possible that your bedroom, if you sleep with the door closed and with another person, if quite possible, you're pushing that level.  And even at 1,000, so this blue, these blue dots here. So ideally, we want everything to be up top, but you can see the blue dots are already starting to dip. So we don't think as well. And our bodies don't heal as well when there's when the air is stale. And the common proxy is carbon dioxide because we breathe carbon dioxide out, we exhale it. And like I mentioned, I'm real quick, I think it'd be interesting while we're on fresh air that, and I know this is about CO2, which is different, but there are areas that have really poor outdoor air quality. So I think it's important to touch on that as well as that in a lot of scenarios, it likely takes less outdoor air than we currently think or per 62-2 guidelines. Exactly. So and ASHRAE 62.2 is the industry standard for residential fresh air. And what Michael's talking about in doing all of the testing that we've done, it appears that you don't need levels that high to still get good results. And we'll actually be touching on that later. We've nicknamed the system that we use for that. It's a cheeky nickname. It's called badass HVAC. And it combines a bunch of factors, which we'll get to in a little bit. But yes, important thing, and you have to watch outdoor air quality, which we're going to get to as well. And then I mentioned, so outdoor air is 400 to 500 parts per million, depending where you are, and the target indoors is 600 to 800. So that's what you want to target. And this I thought was cool. I want to thank Christoph Irwin of the Building Science podcast. He found this study that the main conclusion was if you use recommended fresh air levels, so that amount of flow, they have the same effect as a 50 to 60 percent inoculation against the flu. And I thought that was pretty cool. So filtration, humidity control, fresh air, they all have very key roles to play here. Although I don't want to oversell them. I don't want to make them sound like it's a bigger deal than it is. But in all of our air quality work, regardless of what we're trying to control, those three really do seem to help. And Michael, here's what you were talking about. So if you're going to bring in a lot of fresh air, and I really should say fresh air in quotation marks, laser beams. So you have to watch what the air quality is outside. And there's a very simple thing called the air quality index. This is tracked nationwide.  So you really want to pay attention to this when you're adding fresh air to a building. But ideally, we would automate this. So from a homeowner's perspective, you know, in the United States, most houses don't have a fresh air system. And going back to that ASHRAE 62.2 standard that you mentioned, what that typically looks like is having it can be done one of several ways. You can have a duct running from the return side of your system to the outside that's filtered somewhere along the line that's pulling air from outside into your system that gets discharged the supplies, or you could have what's called an ERV or an energy recovery ventilator or heat recovery ventilator that provides balanced ventilation. So it's discharging still air and bringing in fresh air from the outside. So this is the type of, you know, that's kind of what these ventilation systems look like that we're talking about. So the standard code building doesn't have it. There's also just what is common in my area, at least where they have just exhaust only where it's a bath fan that is supposed to run 24 seven and things like that. So lots of different ways that it's accomplished and some of which are much better than others, I guess is a simple way to put it. I would say the exhaust only or the bath fan method is probably, you know, the worst way to do it. But just because you can't filter it and you don't know where that incoming air is coming from. So the other way is you actually have control of where it's coming from and you can filter it. Yep. I'll paraphrase Joe Steebrick of Building Science Corporation.  Yeah. So it's one way to do it. So you can depressurize the house, which is sucking, you can pressurize the house, which is blowing or you can balance it. But that balance is actually not what I'm talking about. For this particular slide, filtration, humidity control and fresh air, they're all interrelated. So if it's really humid outside, you don't want to push a bunch of outdoor air in or you need to dehumidify that air cool and dehumidify it. So there's a balance. We're in a pretty good season right now for most of the country where you can probably just open windows at least somewhat and be okay. And we'll touch on that a little bit. But if you change any one of these factors, you're going to change the others. And that can be a pain to manage manually. But there's inexpensive manual things that we can do, which we'll get to in a little bit. So just to reiterate the takeaways, so this thing is transferred through sneezing and coughing. Humidity, you want to keep between 30 and 50 percent relative humidity. Filtration, if you want to filter the viruses, you need to be using at least a Merv 11. And as we saw, it really should be a 13 or higher. And fresh air, you want to do what you can to achieve 600, 800 parts per million.  That's again behind me on my bookshelf. There's a bunch of sensors there. One of the best if you're going to watch for CO2 and particulates is the IQ air monitor, which also has an app which will let you watch air quality index where you live as well. So even if you don't have a device, you can use that to watch air quality. Or you can watch air quality through a bunch of different apps. Most weather apps track air quality as well. Okay. And let's pause for questions. Cool. So let's see. Yeah, I was going to say the same thing. One of the ones that is popping up is lack of air changes per hour. For some reason, I can't find it now. So what is the group thoughts on air exchange rates, ACH getting tighter in homes and commercial enclosure enclosures? What impact will having a tighter enclosure requiring less air changes have on indoor air quality? And I think that goes back to what Nate was saying as he's involved in a lot of the deep retrofit type of work. And they're finding that it requires less air changes per hour than probably a leakier home. I'd say a lot of that comes down to PM particles, right? As your house is leakier, you're probably getting a lot of infiltration from attics and crawl spaces and areas that are increasing your PM levels. And that is likely different than controlling virus stuff. So going back to the question about the commercial buildings, it's going to be, there are so many different types of commercial buildings out there. Some are very similar to residential where the physics are basically the same. Some you have high rises where you have stronger stack effects that are pulling on the building. We did a 30-something fan test on a commercial building that was a million square feet last year. And this had exhaust fans running. And part of that issue was that the software that was running these fans wasn't set up correctly. So there's all sorts of other issues that you can run into with commercial buildings. And there's not really a universal answer. But the same type of testing and diagnostics is going to be required. It'll just go down a deeper rabbit hole into it for commercial. Again, depending on the type of building, especially if it's a restaurant, if they have commercial kitchens in there that are going to have stronger exhaust fans, they're going to be putting a much more negative pressure on it, that's going to have an impact too. Great. And this goes back a while.  How are the differences evidenced in typical residential ductwork velocities? Can coronaviruses adhere to sheet metal and how long can it survive? So aerosols and droplets, that would have been a better thing for Dr. Miller to answer. She did tell me that technically a droplet is supposed to be like 25 and above. So I'm mixing the terminology here because we're looking for a homeowner level. But anyway, I'm mixing the terms there. And as far as how long can it live on sheet metal, I don't know, steel was one of the things in there, but that New England's Journal of Medicine article, it had numbers on that. So go look for that study and take a look. Okay, that's probably Ubergeek for our homeowners here. And also on, so they're asking about humidity and viruses as well. I would just say the reason that humidity affects it is the particle size, right? Am I understanding that correctly? As I'm a little layman in this area, but as humidity changes, what it's carried in, which are droplets of, you know, saliva or whatever. And so humidity affects the size of that and the ability of it being filtered out by a standard filter that is in someone's HVAC system. Is that a correct assumption there or way of putting that assumption is probably the wrong term, right? We're all like out of our element here. We've lost our expert to answer that question. But that that is how I read it. And also like the 70% of droplets being less than 2.5 microns. The drier the air, the faster it's going to evaporate and the harder those particles are going to be to capture. The question that I don't have answered that I'd like to understand is once those droplets hit the filter and dry, can the viral particles slip through the filter then because they're so small? And I haven't been able to get an answer to that question yet. Well, just spray water on your filter. There we go. It's a great idea. Keep everything wet. All kinds of good things happen when you see things wet. We have some other good questions on here too regarding UV lamps too. But our expert has unfortunately had to leave and go handle some other stuff. But I see an article coming out of this too that we can write up and address some of these questions here to follow up. There's some other questions too. How soon we'll have this? I plan on editing this recording today to get it posted onto our YouTube channel later. So we hope to have this up soon. So if you have to leave early, you can finish it up later or show it to somebody else. I think that wraps up a good chunk of that. There's some other questions in here where we're going to answer later in the presentation. So I think we can keep on trucking Nate. Great. Yeah, hopefully we can finish in the hour and a half. So I got 18 minutes and I'd prefer to take less than that so we can talk about stuff. All right, Sam, you said you had something. Nope, I think you still have control. Okay. So four levels of interventions. And this is again, we're trying to adhere to the do no harm principle. This is a system that we've developed because we find that things tend to fall into these four buckets. And the first one, level one interventions are zero to 100 bucks. Let's see. Is it going to let me? There we go. Level two is 100 bucks to 1500 bucks. And we're going to look at what some of these things look like, but just kind of give you an idea. We're building a framework around it. Level three is HVAC contractor installed. You probably could have this done by somebody else as well. But generally these are going to be HVAC measures. And level four is getting into the type of practice that we do where we're doing comprehensive upgrades to homes for both insulation and HVAC. And to do those, you really have to do further planning. That is not something you want to shoot from the hip hop because they're not inexpensive projects. What I want to come back and focus on though is level three, the HVAC contractor installed measures, which is what those UV lights are that are driving house Sam and I crazy. Those are risky if you don't do any diagnostics. And actually this is, it's a great line that I love here. You cannot ascertain what the solution looks like without a discussion with your clients. So people shouldn't just shell the stuff out there. But the most important line is prescription without diagnosis is malpractice. And there really is a corollary to that, which is without follow up, you're also committing malpractice. And so this is something that we're very particular about in our practice. We want to make sure that things that we did actually worked and they didn't try and understand why. And whether or not they get fixed, at least we understand it for the next time. Because usually the failures at this point are very, very minor. But prescription without diagnosis is malpractice. Very, very important point. And so that brings us back to where we started first to know harm of a Hippocratic oath. And some of the stuff that it might be placebo, we'll find out, but none of the things that we are about to suggest are likely to hurt you, unlike if you start pumping a bunch of ozone into your house. So back to the do no harm. So say you do all the stuff and nobody in your family gets sick, and you don't really have those virus carrier particles to take out. Well, darn. So now you're not breathing pollen anymore. You're not breathing mold spores or dust might poop or pet dander or bacteria, like all of these things would get tackled. So it still adheres to do no harm. Good filtration is really the first line of defense for all kinds of problems, not just viruses. Okay, so I promised to talk about this earlier, and hopefully you're not hearing my dog in the background. Welcome to working from home. So this is a level one. So this is under 100 bucks is what we're looking at here. And this is a little temperature and humidity monitor that's a client of mine found. It's 20 bucks. And it this this one in particular is Bluetooth. So it's actually a data log. And you really want data logging. So data logging is keeping track over time of what happens. It's not just like this is actually the 12th monitor in my office. This is just a little temperature and humidity gauge. But it tells you what the last 24 hours is. But this doesn't log anything. So if I want to understand what was the temperature and humidity this morning at 2am, I have no idea where if you log it, you'll get an idea. And this will help you understand, do you need to increase your humidity or decrease your humidity. So I recommend that everybody go snag something like this. If not this tool something similar. And speaking of something similar, this is a product sold by friends of mine over at True Tech Tools. So if you're an HVAC contractor and you don't know who True Tech Tools is, what's wrong with you. But they sell all sorts of diagnostic tools. And this is one that has a little higher quality that's meant to be left behind by our jobs. So I use this particular one in my house. And for the non HVAC people that might be listening, there's what's called the psychrometric chart that we use to see the relationship between temperature and humidity. And on that chart is what's called the comfort zone. That's really the ideal sweet spot of where we want to be living regarding our indoor temperature and relative humidity. And so you can actually do data logging with this. And it'll show you if you're inside or outside of that zone, depending on what you've collected. So I have one in my crawl space, another one inside. So you can buy a six pack of them and have them in different spots in your home. So it's a really cool tool. I've enjoyed it. It's just a matter of how much do you want to geek out? Because you can go crazy. You've got a bunch of geeks on today. But we're trying to keep this reasonable. All right, so I see a couple of questions. I want to at least just address briefly. So Mike Lampkin, is it hard to retrofit Merv 11 filter to an existing forced air system? Yes, we're going to get to that in just a second. I think all the other questions we're going to tackle by the time we're done here. Levels one and two. These are simple things you can do that are inexpensive. And the point is to A, let you feel like you're doing something. And B, have some odds of it actually helping. So none of these things are a waste of time or money is what we're aiming for. Okay, room humidifiers. Particularly if you are mold sensitive, something like this would probably be a better idea than a whole house. But these are inexpensive. This is the one I actually just bought, showed up two days ago. Important note here that my friend and another researcher, Dustin Poppendick mentioned, he said, make sure you're using clean water. So distilled is most preferred, but that's going to be a pain to keep in stock, particularly as we shouldn't be going to the store too much. Or you can put in a reverse osmosis system, which is what I have in my house. And that, that water is going to be way better than just tap water. We'll take most of the garbage out. Okay, the filter fan. So circling back to this, it's a 20 by 20 box fan. Make sure you find one that has a switch on top or else you have to do what I did here. Is the fan or the filter should go on the back of the fan. It should pull air through the filter, not blow it through the filter. But in this case, I wasn't paying attention. And this fan has the switch on the back of it. So this is backwards. But then you buy a 20 by 20 high merv filter. So this is a merv 12. And this one happens to be a good deal. I don't know why the merv 12 are 15 bucks a piece. There's a two pack for 30 bucks. And then you just duct tape it to the fan and just use it like an air filter in your space. So turn the thing on low, set it in a room, let it rip. Here's what the filters look like. This is just an example product. You can snag whatever you want. And Shelly made mention that there's also versions of media filters that have activated carbon in them. And those help reduce VOC nitrous oxides and ozone. So that's a good idea if you live near a busy road. Or if you're sensitive in general, that's not a bad idea. That adds 20 or 30 bucks per filter to them, something like that. I think it's also important to note here real quick on filters. And I forget all the acronyms, but there are some other ones like FER and things that aren't really regulated. They're made up by filter manufacturers that are often sold in box stores and things like that to act like they're better than they are maybe is my sense of it. And so we really want to focus on the MIRV, which is an actual standard. And so I think that's important to note for homeowners. Yes. Yeah. Yeah, look for MIRV ratings because we actually know what they are. They're tested to certain standards. You're more likely to get a good product if you buy a MIRV rivet product. So good point. Okay, fresh air. This is something you can do that's simple that hopefully you have right now. This is my range hood and then where it comes out. So you can turn on your bath fan or your range hood. It's important that it vents outdoors. And particularly with range hoods, a lot of them, they're known as forehead greasers. They don't actually go anywhere.  So that's not going to work. They need to go outside. But you can turn one of those on and then crack a window. So that's going to create a flow of outdoor air. And that's actually what's going on in my office right now. I've got my office window open about an inch and it's pulling stuff in. The bad part is it can pull garbage in where I live. Almost everybody here burns wood. So almost every night I get to smell wood smoke. And I don't like that, but I haven't installed the full HVAC system in this house yet. We bought it as a full closure last year. We just haven't made it there yet. Another important note, this is going to change humidity levels. If it's warm outside, it's likely to increase humidity levels. And if it's dry outside, it's going to decrease humidity levels. And again, you want to aim for that 30 to 50% relative range. Using the filter fan as a fresh air system. And this is something that Linda Wiggington of the RAKIS project does. And we'll put a link to one of her studies in one of the groups in a little bit. But you can put one of these fans in your window and then block it like you were mentioning, Sam, so you can put a piece of foam board or cardboard or something like that so that the fan is only pulling through the fan and it's not going to be short circuiting. Yeah, this works much better for the fan for the for the folks like us that have highway. You put it a window and block the sides. Yes. So this is a fresh air system for that. But as your outdoor humidity is increasing, that may or may not be a good idea. Sure. So it's a balance. And so outdoor conditions, these are the best practices. You want to watch the dew point, which whether or not you understand it, just look at your weather app. Every weather app has dew point on it. And then watch your air quality index. If it's bad outside, you probably want to filter. Yeah, I think it's a good idea to say this is where it's good to have some sort of monitor. So like what I've been doing recently is opening windows and turning exhaust fans on because my system isn't highly complex or more like a normal house would be, even though it's fairly leaky, but I'm able to open the windows and then monitor the humidity level. And when it's, you can kind of trend when it's rising, which it's been really rainy and humid here. And then know when to shut those windows. But it's had a very drastic effect on primarily PM levels and VOC levels. You know, my monitor, I can't detect a whole heck of a lot other than that and humidity and temperature. But so it's been interesting to kind of watch and play with that over the recent time period. Yep. Yeah, that's a ball. That's going to be a level two recommendation is getting an air quality monitor. And that's what I was going to mention earlier too about the using the fan in the window is that, you know, I like to measure my monitor humidity regardless. But even in that case, it's a good idea. And plus with that, you're going to be pressurizing your house instead of pulling on it, which is always better. You always want to pressurize your house instead of pull on it. And so that way, you know, as you create that positive pressure, there's going to be an equal negative pressure someplace else where that stale air is going to expel through leaks in the house. And that's okay. Yep, exactly. The only thing to be careful there is if it's really cold outside, you might be driving moisture into the building materials. Sure, sure. But that's that just something. There's so many things like, again, the complex but correct path takes a lot of learning. And I don't want to blow anybody's mind. Anyway, so digging into level two, so this is 100 bucks up to 1500 bucks. Pretty much everyone, if you live in a green grass climate, so meaning your grass stays green most of the summer without watering it. If that is the case, you really should own a dehumidifier. But can you go back up one, Sam? Oh, one more. There we go. So an energy star dehumidifier is the one to look for most of them are at this point. Look for a model with a pump.  Set it to 50 to 55% relative humidity. Curse of these is they only last a year or two. Sucks. That's just how they all are. If you read the reviews, none of these are great. I have no particular model to recommend. They all stink relatively equally. And again, that can vary depending on where you live too, because in some places you may only need to run it for certain times of the year. Some places might have to run it more. So if you're really in a really hot human climate, you might have to run it a lot more often than somebody else does. Well, even here, ours kick on in April and then it'll turn off till November. We're a cold climate. You should leave them on regardless. Yeah. Do not ever turn them off. Yeah. Just leave them on and if they don't need to run, they won't. And if they need to run, they will.  I would also check the setting where it actually reads out the relative humidity depending on the model you get. They're not that accurate. So I would double check with a more accurate tool to see where you actually are. Good point, Sam. Okay. Indoor air quality monitor. I've done a lot of research and work on these. And the curses, the one in this picture on the left furthest to the left is called a FUBOT. It's by far my favorite and it came off the market a couple months ago. And there is no other one that I like well enough to recommend which sticks. So hopefully that will change in their future. In general, these are 100 to 400 bucks. And the things you want to look for are measuring temperature, humidity, PM 2.5, that's dust, and TVOCs, which is chemical pollutants. And depending on what your goals are, carbon dioxide might be good to look for as well. And this picture, this, that's my old house.  So we've been learning about these for a while. But if you Google which IEQ monitors are best and why that should come up on the top. Or again, we'll post a copy of this so that you can click on it later. Yeah, this was one of the questions that was in the question boxes, you know, what type of monitor to recommend to homeowners. Yeah, that's great. The biggest curse that nobody else has. Well, so I want two things. Well, ideally, I want the temperature, humidity, PM, and TVOCs. So those are my preferred measures because the TVOCs teach you all kinds of things. They go off all the time when you have no idea what's going on. But I've come to trust the sensor. If it says there's something going on, there probably is. So anyway, I want those four measures. But the, and I want them to be relatively accurate, they don't need to be dead on, but I need to at least trust them.  So I need a good dashboard. And the curse is nobody else right now that I've found has that dashboard and those sensors that are relatively accurate.  But that's where we are. Everybody keeps asking me, what do you recommend? I don't recommend anything right now. Try something. The IQ errors, probably one of the better ones, but it doesn't do VOCs. Okay. So also in level two, I mentioned this earlier, you can run a high end air purifier. These run between 600 bucks and 1000 bucks. These are good for a room. I wouldn't trust them to do more than the room that they're in. I mean, if you've got a door, that's the only thing that connects that room to something else. There's not going to be that much airflow through that door. If you put it in a big space, it's probably going to do a decent job of a big space. But Austin air and IQ air, these are the two best reviewed ones that I see. If you look for them, some of them will tackle chemicals as well. And that's where the activated carbon might be a good idea. And these would be a good option for like, say you have a kid with asthma or you have asthma in your sensitive, you might put that in your room or your kids' room.  And then the, I think this is the last level two thing. So reverse osmosis is probably a good idea for a humidifier, be that for a room or for a whole house.  This particular model is 200 bucks. I bought and installed two of them. Now, we're going to move to level three, because there are a couple of things, like I see Colin Zweiga, if I'm not butchering his name too badly, says in my home, I have a balanced HRV with it cycling on and off. Should I fully ventilate the air with the HRV? Yes, I would lean towards running that thing more. And HRV, that's a heat recovery ventilator that has a duct that goes into the house and a duct that goes out of the house. So it exchanges the air in the house. We're actually not big fans of those things because we've found that they can create humidity issues that are difficult to control. But if you haven't used it. Okay, level three, media filter. We already touched on this pretty heavily. But if your system isn't built to have a media filter, you really should, if you want to deal with this, you need to have it renovated, have the duct system renovated so I can do that. And this is best done at HVAC replacements. Because doing it separately, if you aren't taking the unit out and taking apart, it's going to be more expensive. It's going to cost at least a couple hundred bucks more, because it will take more later. I'd say probably double. Okay, there you go. So this is a fair statement as an HVAC contractor, it just, it is something to plan ahead for if you're going to do it well. I mean, you can slap cabinets on, but it is best to kind of do a little bit of data digging beforehand and not just do that kind of scenario. So exactly. And we're going to get to that just a second to recall that a bad. So another thing to consider is a whole home dehumidifier, or sorry, a whole home humidifier. There's also a whole home dehumidifier, which can be an option. And we have come to like the water saver model, because they use a lot less water. So if your house needs more water than what this unit can put out, it's probably too leaky. So if you put a huge amount of moisture into a house, particularly in wintertime, you're going to cause issues. I can't tell you how many moldy roof decks I've seen, because these humidifiers have been left just to run all the way. It's very, very important that they adjust based on outdoor temperature. It must do this. You can do it with, you can get an integrated control with the humidifier, or most thermostats will do this as well. Shouldn't say most thermostats, but a lot of them will. Nest and Ecobee and pretty much all of the high-end thermostats for all the brands will adjust based on outdoor temperature. If you are mold sensitive, don't put one of these things in. Be very careful, because it's going to be putting moisture into stuff in your ductwork, and that might make your symptoms worse. Again, use filtered water if possible. And one of the biggest things I see on these is people don't change the pads often enough. So read the instructions, have extra pads on hands, get a service contract where your HVAC contractor does that for you. Whatever it is, don't leave that pad in there for years. It will get nasty. Would you agree, Housh? Yes, they do get nasty, often overlooked, and not kept up on as well. And so, I mean, with a reputable company, it's going to be part of their maintenance program or whatever, but definitely one of the nastiest things that I feel like I come in contact with in an HVAC system. There you go. If you are big on DIYing, I would recommend putting in your Google Calendar to go check. Put a reminder in every three months and go take a look, or whatever the change recommendation is for that model. Okay. I mentioned this earlier, automation. So if you do this right, and at level three where we're talking an HVAC contractor being involved, you don't have to watch outdoor humidity and air quality. It'll do everything automatically, and it's just not that hard. And to that end, this is a system that we developed. In fact, Housh named this. I showed him a picture of a job that we did that had this gigantic return duct, and he said, that is a big, you know what drop, and so we call it a big air drop to avoid swearing. But its official name definitely involves a swear word. And it's really simple what's involved here. So again, filtration is a big, big deal for all sorts of things. And if you're going to use a media filter, you need to let that thing breathe. So we make the return drop. So the return drop is where you've got to see the curve side on the bottom. That is the return drop. That's just the name of the duct on the return side that goes into your heating or cooling unit. And so that return drop needs to be the same size as the filter. You put the media filter in the drop, and then the other piece of it, and this is not all of them get this, but it's a damper fresh air duct going outside. And if you live in a place where you have systems in your attic, it all looks the same. It's just flat instead of being U shaped like this. I've got to say, those are some sexy pictures there too. Who did those drawings? Who was that? An important part of the bad system there is the filter in the horizontal location like that, or which is typical in my part of the country. It is different, as Nate said, in horizontal applications when it's in the attic, but is having laminar flow across the filter helps get a lot better utilization. So it's important. All right. That was some jargon there. What does laminar flow mean, Hush? Uh, so laminar versus turbulent would be where things are moving in a straight line, equally, kind of throughout the duct system versus if you're in a turbulent area, you get a lot of swirls and areas that aren't utilized. So you could have a filter in a location that is maybe only getting 50% of it, 50% utilization, I guess, or smaller, or there's areas that just aren't doing the same work as if it's in a laminar stream. Yep. The easiest way to think of it, in my mind, when you think of airflow in the duct work, imagine going to a stream that's flowing quickly and you see a rock in the middle of the stream and the stream is going around it and it's getting turbulent. Air at these pressures flows just like water. So if you look at it and you imagine water going to your duct system and you think, boy, I think the water wouldn't like to do that, the air doesn't want to do it either. So I could see how this could get confusing to some people watching that don't know anything about this. So if they're referring to the bad system, they're referring to a good thing. So just keep it in mind as we move. Big air drop, yes. And so much you're not swearing. So we have cheekily named the full system. So I want to take a step back. What we're dealing with here, we're dealing with filtration, humidity control, and fresh air. But that is not all of what an HVAC system should do. So how should I already named it the bad? And I was like, all right, what can we do to make this a badass system? And we named it this so that it's sticky. And basically people start talking about it and using it. So that's the reason it's there. And we say it's one system to manage it all. Now, what does all mean? This is from the HVAC 101 chapter of my book, which is a free download. And there's six things that every HVAC system should be able to do. They should be able to do load matching, filtration, dehumidification, fresh air, right place at the right time, which is also mixing like stirring over the regret, and humidification. Every system should be able to do this. Every car that has air conditioning can do five of six of these. Most houses can't do anything with their current HVAC system. We put up with a lot more mediocrity than we realized because it's just something that's stashed in our basement or crawl space or attic. So it's important to be able to do all of these. And this is the full system of skip to the end of a presentation. So I did another presentation. Currently, it's aimed for HVAC contractors. It'll be mostly understandable by homeowners. I'll do a homeowner version soon. But tackling those six things, you want to be able to do load matching, which is matching how much heating or cooling the house needs in any moments. Good filtration, which we've been talking about, dehumidification, which I'm not going to dig into what's involved there. But that's a special system, fresh air, mixing, and humidification. So this is a humidifier hanging here. We can argue about exactly how you install and so forth. So there's probably a bunch of HVAC contractors right now that are like, what are you doing? I don't care. We can discuss that later. But having a humidifier if you are in an area that has cooler winters is probably a good idea. So that is badass HVAC. And I'll put a link for the video in it later. I think we should hit on real quick on going back to questions real quick. I know we were talking about 62-2, which has to do with fresh air ventilation. And not a whole lot of homeowners are going to understand that. So we should break it down a little bit. So my thought on that is ventilation in general has to do with how many times you're exchanging the air inside your house with air outside your house. And oftentimes that's related to cubic feet per minute, right? And so a good way to think of it is, we live in a 3D world. So the air inside our home is taking up a volume. And so 62.2 rates oftentimes from Nate's data and others' data is higher than we need to exchange all the air inside our house. And that is going to obviously depend on a lot of factors.  But hopefully maybe that analysis will help where 62.2 essentially refers to how many times we're replacing all the air in our house with outdoor air or so-called fresh air. Yep. And that's a long complicated topic that maybe you and Ihouse will do a program out of something. Yeah. And so for homeowners out there that are new to this, that aren't HVAC people, this is definitely something that your HVAC contractor will need to come up with a good plan for you. And there's a relationship between how much outdoor ventilation you need versus how leaky your building envelope already is versus whether or not your system can handle the ventilation coming in.  So there's more than it should be done without a blower door test. Right. That's how we measure to see how leaky a house is. So there are HVAC contractors out there that do that kind of testing, but that's kind of what goes into this. So it's not a matter of just slapping it in there and calling it a day. It's a little more complex than that. Yep. So now I'd like to widen the lens so we're basically at the end. But what we've been talking about through all of this, so looking at the research and understanding what might or might not help with controlling viruses, all of this at the end of the day comes down to being an air quality discussion. So let's back out and look at it.  And it will deliver generally very good air quality. So we've done a bunch of these and we've watched and is it perfect? No. But it's awfully good and it's way better than it was. So if we're going to widen this back to being an air quality discussion, and then we've talked about outdoor air quality, the air quality index. At the end of the day, if we're going to improve both indoor and outdoor air quality, and we're using all of these tools that we're talking about fresh air and humidification, dehumidification, filtration. Once you do those, the next step is dealing with air quality inside and out. And the best way to do that is to reduce how much you burn things. Because most outdoor air quality pollution is caused by combustion.  So in trying to figure out what do we do next, if I get it to switch slides here, did I leave a blank slide in there by accident? Yeah, here we go. So hopefully most of you here want to continue the conversation. And we have written this to be primarily at the homeowner level, but we know that there's we're going to be a lot of contractors there too. And contractors, you might want to join both of these homeowners, you might want to join the electrify everything group. So if we're going to burn less stuff, one of the best paths to do that is to electrify everything. We're seeing that with Tesla and electric cars. We do heat pumps as part of our projects, which are powered with electricity. Those are powered generally with, well, not entirely, but they can be powered with renewable energy. So electricity is getting cleaner every day. So in trying to figure out where do we point this so that we can continue the conversation, we decided to point it towards the electrify everything group. And then if you are an HVAC contractor and you're not part of the HVAC 2.0 advanced discussion Facebook group, please go look for that and join it. And again, Sam will be sending, Sam, you're sending an email out after this, right? Yeah, we'll send an email out and we'll post it to social media as well. Great. So we'll put those links in there and you'll also get access to these slides. So if any of this is helpful, great. But ideally, this will spark a conversation and we'll start talking about these things. So hopefully it's been helpful there. And then we are at the end. Cool. Let's see. Any other questions we should deal with? Let's see. I had one other from earlier, not in the presentation about filters, which is better compared, or if you compare a standard air filter versus a polarized media filter versus the highest level of MIRV that your system can handle, what would be the better way to go there? Well, I think there's not a lot of research on the ionization or polarized filters and oftentimes, those create other byproducts like ozone and stuff like that. So that's a difficult one. I have personally installed the polarized filters and have clients that swear by them. A lot of that was prior to any research done. I fell in that Dunning-Kruger effect there. So whether that's placebo or not is speculation, really. I mean, it did cut down on dust, which were the things that we were following up and asking about. But whether there's ill effects aside from that are kind of to be determined, in my opinion. Okay. Great. Thank you. Before we take other questions, we got questions. This is BPI. You get a CEU for that. So just put that in the question, answer your name and your BPI number. We'll get that added in later. But I think we're kind of getting towards the end of the question list here. We're two hours in, too. Yeah. For a one hour webinar this year. But there was a lot of content here to get through. For sure. Well, I guess that about wraps us up here. I'll put it on this last slide so that you can see our YouTube channel, the link for that. That's where we're going to have this posted later today. It'll take a little bit to edit and upload to YouTube. But once that's finished, we'll have it up there this afternoon, this evening. And we'll send out a notification letting you know that it's up there. But with this coronavirus thing going on, I mean, this is something that we at RetroTech have immediately been passionate about. And we really hope that this has been helpful to you. As I mentioned at the beginning of this webinar, none of this replaces any of the CDC guidelines. So again, keep washing your hands. Stay away from large groups of people. Keep surfaces clean. That's number one priority. But as far as the air is concerned with your house, we really hope this has provided some information that you were looking for. So with that being said, Nate or Michael, any last remarks? Thank you, Sam, for providing the platform to do this. Excellent. I would agree. And I would say for homeowners that it's probably best in the time being to take some of the level one and level two recommendations. Because there's going to be a lot of the level three or HVAC contractor installed stuff that you really need more time to research and or find a company that is reputable. And this is hard. Like I'm an HVAC guy. I want everything good for our industry. And but at the same time, the do no harm is big on my list. And so just take your time. Don't do anything drastic and do some research and find a good company, even if it takes going through several of them to find that person you're comfortable with. Yep. Sure. Great. I'll second how Sean, go try some level one stuff. Build yourself a filter fan. Get a room humidifier. Try kicking on your bath fan and cracking a window. Those are all things that are well worth trying. And if there's one, the air quality monitor right now probably would be the IQ air to go take a look at. And you need to track and just watch and mark or you buy the $20 temperature and humidity thing. So play with the level one. Well, we hope our next webinar will find us all in any much healthier place. Until that there's a fix for this COVID-19, this is going to take the biggest display of teamwork we've ever seen in our society. So be safe. Be smart out there. Thanks again for joining us. And we'll see you again next time.


Well, thank you for having me out here today. Manufactured housing was a significant part of my congressional district for a long time in Southern California. It was the former home of the Fleetwood Manufacturing corporate headquarters. As you know, Fleetwood's thought of bankruptcy has been dissolved. It's an indication of the challenges in manufactured housing. Not because manufactured housing isn't quality housing, not because it's affordable. It's obviously affordable. It's because of primarily getting credit in the marketplace to buy a manufactured house. Unfortunately, it's kept a lot of people from buying, I think, a manufactured house who folks would love to have. So hopefully, in the process of governance around here, we can find a way to get credit markets, more sustainable credit markets for manufactured housing. It's still a great way for a lot of people to go, especially in retirement communities and on the rest, to get a house for less than 150,000 dollars on a piece of property. And that's still a large part of the marketplace here in the United States. In many places throughout the country, especially in the Sun Belt areas. It's not ironically as important as it used to be in Southern California because of the high price of housing. But in our neighboring states like Arizona and Nevada and other places, in some of the less affordable places, or less affordable places I should say, in the beach communities they've created some interesting manufacturing housing. As a matter of fact, I have a beach house in Newport Beach and a manufactured house in the middle of a village on Lido Island out of manufactured housing. Silvercrest did that product. It's a very great product. It was also in my hometown, Silvercrest Manufactured Housing. They're a great outfit. So I'm a real fan of that housing and I think also it's an exportable product. I think the military, if you've been out to, I'm on the Defense Subcommittee on Appropriations and we spend a lot of money on a manufactured house because we don't use tents a lot. We still do, but many times we use these cubicles. They're much more comfortable for the soldier and it works out better for our military. So thanks for what you're doing and I hope you have a great conference. And if anybody has any questions, I'll be trying to answer that.