This episode of the HVAC school podcast is made possible by the carrier corporation, and I want to give carrier some props, because recently they had a they had a recall normally in thinking. That would be a bad thing, but the way the carrier handled the recall was really exemplary. They had an issue with some of the carrier: green speed systems with some boards that had the potential of overheating. Now it caused zero property damage, zero fires, but they knew they had an issue because some of the heat shields were coming back, where they showed that there was some excessive heat, and so they did a quick recall.

They gave us a list notifying us of the customers that fell under the recall, the systems that we'd installed we're able to go out really quickly and take care of it, and that's exactly what you want to see from a manufacturer. There's no manufacturer, that's gon na be perfect all the time, but the most important thing to me is that they support their products. They take care of their customers and they communicate with their contractors, and carrier is always done. A good job of all of those with me we're also proud to have testo tools as a sponsor.

You know I talk a lot about testo, a lot of guys kind of razz me about it, but I am a big fan of testo and you can get all of the great estou products. By going to true tech tools, comm use the offer code gets gold for a great discount test. Oh tools makes great great test instruments, all the way from very inexpensive, all the way up to the highly premium products that they make, and you will find all of that at true tech tools. Comm.

I also want to thank our newest sponsor, which is with the rector seal & rector seal, makes a lot of different products, but when I want to talk about real quickly, is there no vent line of tamper, resistant caps, and so one thing that they point out Is that the actual international code, the international account could point out that a special tool should be required in order to remove these caps, and so a lot of municipalities are starting to adopt the International Mechanical Code on this subject. There are some manufacturers that make tamper, free caps that just use a Schrader core removal removal tool and if the point of the tamper, free caps is to keep people from tampering with it, then using something that kids use to take the cores out of their bicycles. Isn't necessarily going to be considered a tool that is a specialty tool. So that's why rector seal makes their there no vent product with a special tool that is only sold to HVAC licensed HVAC through HVAC distributors.

So thank you, director, seal for sponsoring the podcast and check out the no vent tamper, freak apps and now the man who graduated high school at 16 and instead of going to college Joe's the bakoma HVAC technician. Yes, we all questioned his sanity, Brian all. Yes, my sanity may be in question in many ways, but the one thing that I will never regret is going into the HVAC trade, which happened very much by accident. Actually, my father was a licensed electrical contractor and building contractor.

He both worked as an electrician and then as a building contractor later in his career, which he still is today, and I didn't want to follow my dad's footsteps too much. I wanted to kind of forge my own path, so my dad and I were sitting down at the kitchen table when I was 16 just graduated high school and graduated two years early and he said alright. Son you're always gon na you're, always gon na want to have a trade in your belt. You can go to college or do whatever you want later, but let's start with the trade.

So we looked at the pamphlet for the local trade school and he said well. Air-Conditioning guys they do pretty interesting work. I think they make pretty good money and off to the races I went and I've never never regretted it. I really like this business.

Another thing that I'm very interested in right now is building performance, and so today's podcast is actually a rebroadcast of an episode that I heard first on the building performance podcast, so that is corporate Lunsford's podcast. I've had corporate on the podcast once before on HVAC school and I listen to his podcast regularly and there was an episode on there where he did an interview with Lou Harriman on moisture in things, moisture and air and moisture and things and how to control, moisture And air and moisture in things it was really interesting. I learned a few things. I had never really considered.

Frankly, it's a fairly technical episode, so it really gets into humidity and moisture in a way that you probably never thought about it before so I think you'll enjoy it and also I'm gon na suggest that you go and subscribe to corporate Lunsford's Building Performance. Podcast. Really, no matter what segment of the industry and there's just a real intersection between building performance and HVAC he's got a really good lot of really good information there, but this one in particular very much applies to what we do day in day out. So thank you to Corbett for allowing me to do.

This he's been very generous with me and I think I'd really suggest that you check out his website check out his podcast. You can look him up online. You can. He has a really good YouTube channel and you can find all of that by going to building performance workshop comm building performance workshop calm, but here we go.

We've got Corbett, Lunsford interviewing Lou Herrmann for his podcast. The building performance podcast welcome to the building performance podcasts from the building performance workshop. I'm Corbett longs for it and we are talking today again with the amazing Lou Herriman, who is the founder of Mason, grant consulting in New Hampshire and also the author of multiple actuary books on humidity control, Lou thanks so much for talking with us. You know it's a pleasure to be here always so listeners Lou and I were having a conversation were in his home and I started asking him about humidity control and then I said, wait stop.

We need to record this, so we were in the middle of kind of getting into the conversation about humidity. I wanted you guys to be able to hear what Lou has to say, because he is one of the world experts on moisture in buildings. So when I asked you how about drying like what exactly is it, how do we start to think about it? You said that there's a basic principle that we start with, which is well when you, when you're thinking about drying. The first thing you want to be conscious of is whether you're talking about drying air or whether you're drying stuff, because a lot of the confusion about demon, if occasionally comes from the desire to dry stuff, which is different and a lot of the confusion about drying.

Stuff has to do with the identification of the psychometric chart, which is very confusing on both sides of that divide. So it's useful very useful to think. First of all, when you're thinking about drying start with, am I talking about taking water out of air, or am i taking water out of stuff? Okay begin with that, and then so my follow-up question to that would be if, in inside, we dry out, wouldn't that as a side effect to dry out the air. Absolutely it would because there's no there's no getting around the fact that water and stuff, moisture and stuff comes into the air and moisture in the air goes into stuff, and that happens dynamically all the time.

All the time. No, no matter what's happening even when it's very dry inside there's some statistical probability that some of that moisture in the air, the humanity in the air will get into stuff, but there's a much bigger probability when the air is quite relatively dry inside that the waters Gon na be coming out of the stuff and going into the air hmm, but it's going in both directions. At the same time, in one of the previous podcasts that you were on, we talked briefly about the fact that up till the 1990s, everyone assumed that the hotter it was outside the more moisture there was in the air, and then you realized, when you were part Of a research team that actually measured things that that was all wrong. What else have you found out that kind of is assumed by engineers that actually, once we apply research to it is not true one of the biggest gee-whiz for head slappers in my career.

In my working career has been the understanding what happens in a home when you change its temperature. Well, let me put it another way: let's start with the fact that in the engineering community, we think about absolute humidity versus relative humidity, absolute humidity, being the amount of water in the air and the relative humidity being the amount of water in the air compared to What that air could hold at that same temperature in the humidity control business geeky folks, like myself, have always said that, while you might have differences in relative humidity throughout a building, because the temperature changes throughout a building the dew point, the absolute humidity stays pretty much Constant independent of the dry bulb temperature and that's wrong. That's completely wrong! How I found that out is measuring things and monitoring things. Much to my surprise, as a guy who spent a lot of time in desk and dehumidification, is that it doesn't take a big change in the amount of total energy in the system.

In other words, they it doesn't take. A big dry bulb temperature change in a house to make a difference in the dew point in that air, because moisture does come out of the material and it goes into the material based on varies. Relatively small changes in dry bulb temperature, for example, give it give you a couple numbers on this. If we have a a dew point of let's say: 45 degrees Fahrenheit, which is a fairly dry condition in the summertime and in a house, that's an air-conditioned.

You know house and if you don't have air conditioning, if you don't have heating you're, just watching the temperature get warmer in the house, because it's heating up, you know because we're not doing any cooling and if we were to go from a temperature of 70 to Let's say 80 in a house: the dew point might go from 45 to 65. The absolute amount of moisture is going to go up by a lot by 20 degrees of dew point with perhaps a 10 degree fahrenheit difference in drywalled temperature. In the absence of any other, the identification or humidification or heating and cooling equipment - and that is because moisture is gon na - be drawn out as the temperature as the dry bulb temperature rises in the air. It's gon na pull moisture out of stuff.

Yes in the house, yes and that's gon na exacerbate the problem. Well, I don't know if it's a problem, it's either a problem or not depending on the range of values you're talking about, but that was the unexpected thing. So you ask for an unexpected thing. That comes from measuring things.

That was a big one for me, probably sometime between five and 10 years ago. You know that became very clear to me. We've always known, of course, if you change the temperature of stuff in the absence of any other change, you change the temperature you're gon na mobilize water, it's going to want to come out of stuff. What was unexpected is that this happens with a two three four.

Five degrees Fahrenheit difference in air 10 average air temperature. That was the big she was to me, but I stressed that we're talking here, not about a commercial building with a bunch of tile floors. What we're talking about is a residential situation where you have absorptive materials like wall board like carpets like fleecy materials for upholstery like books, so that you have a lot of surface compared to the air volume. That's enclosed, hmm! So it's going to be different in a courthouse, a courthouse: were there huge wide-open areas and it's a lot of ceramic tile and you don't have much in the way of fleecing materials in a house where you have a lot of absorptive materials in a relatively small Amount of air, a small change in temperature, will create a significant larger than expected.

That's change on the absolute humidity in the house in the absence of any other factor which that's reality right. Oh, no, actually, no lots of other factors, all right, so we'll set this aside. For a moment, honest on a related note, people say: there's this myth, and I don't know if it's true or not I'd like to ask you since you're the expert. They say that a furnace dries out the house and radiant is preferred because it makes the house more moist and knowing that as much as I know about this stuff, that seems like it's not actually true to me.

Is it actually true or what's the deal? I think it's fair to say that it's true in some respects and completely false and others, and that's like a lot of things in building technology and building sciences, that these sayings and thoughts persist because they have a great deal of truth to them. And yet by themselves they can be very misleading. So let's take that, you know one step at a time if we talk about a forced air system with a furnace, so it's a furnace. It's going to distribute air throughout it throughout a building and the mythology is that that's going to make a dry environment? Well, it's certainly not going to make a dry environment.

If there's a humidifier on the furnace. If there's a humidifier, that's going to add moisture, then it will be whatever the humid of American pump in, but it certainly is true that, in the absence of any other factors, ductwork tends to leak. We know this a daiquiri I've heard about that. I think you know something by that many times so, because ductwork leaks, a duct system will pull drier from outside in the time into a building, because you will have areas of local, negative pressure and areas of local positive pressure.

But the the pressures created by a fan are so big. Now there are a hundred times greater than the then the pressure created by stack effect. Basically, so you will create pressure, differences and that will result in dry air infiltration. That probably will not happen as much in a house - that's heated by radiant heat.

So yes, it's true that houses with furnaces tend to be drier than those with only radiant heat. But if the radiant heat is also well-ventilated, then the house of the radiant heat might be a great deal drier because you might be getting adequate ventilation from outside. So let's say all things being equal. A house is airtight insulated, ventilated to the standard that is enforced by the 2012 IECC blah blah blah, and one of them has force difference, and one of them has boiler would based on your logic.

It sounds like we're not running a humidifier, but they would be. The same. Humidity is a. They will be the same.

They will be the same and they'll both be pretty good because to meet the requirements of the energy codes, that's going to be a heat recovery. Ventilator yeah interesting, but they will also be drier. They will be drier than many houses because of the fact that they are being ventilated to code unless you're in the Canadian North Rim, the northern tier, let's say Minnesota - you're - probably not going to use an enthalpy heat exchanger to do the ventilation. So you're probably going to be losing humidity from inside.

So when you're ventilating in the wintertime to code continuous ventilation of 90 to 65 to 95 CFM, you know in a house that's going to be a continuous stream of air that will always be drier outside than what it is inside. So both the radiant heated house and the furnace heated house are going to be drier unless there's humidification or unless there's an tepee heat recovery, which is to say that not only are you're covering heat from the exhaust air, but also recovering humidity from the exhaust air. So, since we're going down this path, we will get back to how to think about drying in just the principles, because I'm really interested in that the enthalpy dragon we're talking about erv, an energy recovery, ventilator versus an H RV, which is just heat recovery, ventilator she's, Like sensitive Laurie, so there's a first of all there's a big argument about which one you should use in mixed climates and I'm from Chicago you're from Portsmouth we've got. People in Texas has some heating, I'm sure Atlanta is heating dominated, but they still have a lot of air conditioning which one are you supposed to use.

Is the question number one number two: the manufacturers seem to be kind of building these hybrid systems that can kind of do both if they could do one or the other and and so do those words still apply ERV versus H, RVs or are there kind of Hybrids now that are kind of in the middle and which one are we supposed to use and win, beats the heck out of me. It's it's still a pretty complex question, partly because, as you say, the hardware is evolving. The big deal here to me with ERV S & H, RVs, is actually not so much a question of whether it should be recovering enthalpy or whether it should be curving just sensible heat. You have to know that the first part of my career was selling enthalpy heat exchangers, so I know he's biased, I'm a big fan of enthalpy heat exchanges for many applications, just not for houses and that's because usually humidity is a pollutant that you want to get Rid of in a house more hours than you don't so if you have air that is drier outside.

That's probably what you want more of the time, then the humid air going out, but it depends. It depends on whether you're talking about public housing, where you're talking very densely occupied highly humid indoor environment, hard to tell what people are going to do when they're living in that environment well and how many people are gon na be and what they're doing, as opposed To two semi-retired, you know yuppies living in 4200 square feet where it's quite dry inside because nobody's doing any cooking in there at all. So it's very different and it's difficult. I think, therefore to say we should be doing this versus that, but in general I think enthalpy heat exchangers are not the wonderful panacea that I certainly believed they were when I you know in 1976 to 85, when I was selling those things for hospitals there.

It's a all the time, there's no question that everyone should be using at the be heat exchangers, but in a house I think the questions were nuanced and in terms of the technology, what you really want to avoid is you is you want to be able to Modulate the amount of recovery, so that you're not recovering something you don't want to recover. You don't want to recover moisture a lot of the time in a house over 8760 hours of the year. There's a lot of time. You don't want any bit humid you back in the house to me it's less a question of the membrane technology and more question of the controls.

So getting back to the principles of how to think about drying. We've got the two different segments: we've got drying, stuff and drying air since we're talking about buildings and specifically residential buildings, in what we were just getting into. Why don't we talk about drying air for a minute? What what within drying air are important principles that are kind of basics, for everyone to understand, if I think the the most important thing to think about when you're thinking about drying air, in other words, you're. Looking for comfort, you're, looking to prevent significant damage to a house you're trying to keep the humidity the amount of water vapor in the air at a comfortable level, and if we're talking about taking water out of the air, we're talking about the cooling season when you're Taking it out of the air, most important thing to think about is where the humidity is coming from, because that will tell you a lot about the most cost-effective in the simplest way.

To take too much water out of the air is where it's coming from. So in a residence as opposed to a commercial building, you have a couple sources, the biggest and the most important one in a residential situation, a single-family residence is cooking. Why is that different than showers? People think a lot about showers and the kind of idea making it gon na put a lot of humidity in the air and showers and people grow mold, because they don't think they do many shower taking too many showers you like to clean, and so therefore you Got wall you know, if you think about the time that you're taking a shower is not a lot of hours, whereas cooking can be quite a lot of time and it can be a whole lot of water into the air that may or may not be exhausted. You know if you've got a, you know, shower toilet toilet exhaust in the bathroom and you're, not using it.

Then yeah you'll have a let's say: 10 15 minutes worth of high humidity in there, but with cooking. You know a 10 minute cooking session. That would be a pretty short one mmm, whereas some people can cook for a very long time where, if you are, you know from the Indian subcontinent you're going to cook for a long time to get a good effective. You know curry and so forth.

You're from Latin America, you might have, you know, sauces that you want to cook for a long time. You're gon na make coffee Lou Harriman style. It's a little bit more complicated. It's good anything good takes time.

Yeah everything good takes time and there's gon na be a water vapor. You fall from that and we don't always remove it from the house. So that would be number one principle of keeping the house at a comfortable, humidity level and taking water out of the air. Is exhaust at the source exhaust at the source when the source is producing water, vapor and so in a bathroom you'd like to make sure that, if you're taking a shower or taking a bath or drying clothes in the bathtub that you are exhausting that that extra Humidity in the kitchen you'd like to make sure that you're exhausting from the kitchen when you are cooking okay, so those are two big things that you really don't have to worry an awful lot about in an office building.

There are very few office buildings that have a lot of people: cooking, curries and their whole. You know, are making boiling pots of pasta, for you know for 20 or 40 minutes, or so very really happens, and not too many people take a shower in the middle. The office - that's a rare thing to have happen so saturated. Maybe we can get benefit from them.

So that's that's one thing that happens in a house that doesn't happen in a commercial building, but the thing that does happen house these days exactly like a commercial building, is a perceived and a real need for ventilation. Air to dilute indoor air contaminants that has been at the root of a lot of humidity control problems in commercial buildings, which is to say humidity too high, because we have ventilated without drying that ventilation, air and that's what we are having now in houses is that We are ventilating without dehumidifier, because there's no code that requires us in either commercial buildings. There's no guideline that the commercial buildings are residences. It says that you should dry the ventilation air, so we don't because nobody wants to spend extra money for stuff it's extra and therefore we end up with more humidity in the house when we ventilate, because if you look at the 8760, our the the full-year 8760 Hours is what we have in a year and if we look at even a mixed climate, everything except a very, very dry climate, of which there very few, the bulk of the load, the bulk of the load that you have to take out of the incoming air.

In the new road, meaning the actual water, that's coming in on cooling load, the heating load, the DIA minification, the humidification load, it's all about the ventilation air and, in the case of demon, off' occation in all, except for northern climates and high-altitude climates and desert climates. The ratio of of humidity to take out of that ventilation, air compared to sensible heat, is anywhere from from three to one or five to one, in other words, in the Boston area, for example, you have to take about five times as much load in terms of Deification out compared to heat out of that incoming ventilation, air, so you've got a cooling load. You have to cool the incoming air, you know in Boston, but you have to do you modify it too, and you have to do a whole lot more dehumidification of that air. Then you have to do cooling of it all right, so I've got a really really quick tool tip corner here.

I've addressed similar things to this in the past, but I just want to kind of nail this down. So we talked to in the episode with Jim Bergman, about checking the charge without gauges and a couple things that you really need to be able to do in order to check the charge without gauges and, like I said I know, I've talked about this before, but I think it's really important for you to know this. You'd have an accurate line, clamp, so a line clamp that measures line temperature very accurately thermistors are better than thermocouples, although they both better than what we were using years ago. I remember when I first started in the trade we used to actually like duct tape or electrical tape or take a piece of ARMA flex and tape it around a pocket thermometer to measure superheat.

That's how we started out doing it and what I tell people is a at least. We were checking superheat when I started, and so you need to have a good way of taking a line. Temperature and a thermistor is better than a thermocouple, and you need to also have a way of measuring, wet bulb and dry bulb, air temperatures reliably and one of the easiest ways to do this inexpensively. So if you just want a bare-bones bare minimum way of doing this reliably and regularly, but the lowest possible investments are your new technician out there.

You realize that you don't have a good way of doing this, but you want to be able to try out the things that we taught in the episode with Jim Bergman, about checking the charge without gauges. Then I'm gon na suggest that you get a test. Oh one, one five, I that's the clamp, that's the Bluetooth clamp. I mean it's a really high quality, Bluetooth, thermistor clamp.

It does a really good job. When I say really high quality, I mean are the things out there that are maybe better, maybe a little more accurate sure. Of course it's not a super expensive product, but for what you're getting you're getting a thermistor clamp a Bluetooth, thermistor clamp at an excellent price, especially if you go to tech tools and use the offer code get schooled. But then also, if you want to measure the air temperature wet bulb dry bulb, you can use the 605 I and that allows you to do it actually in the duct.

So you can, you can actually calculate if you get to 605 eyes, you can calculate delivered capacity, but even if you don't want to do that, just get one one, one five eye on one 605 eye and you have you need in order to measure in order To test the system and see if it's functioning without gauges so long as you've done a prior benchmark or somebody else has just gives you a really really good tool to start doing that and start practicing it, and I think you're gon na find that you'll learn A lot through the process now here we go back to Corbett. Let me break it down we're bringing in air from outside we're exhausting air from inside to outside we're rubbing up against each other, and we've got an HRV. That's just gon na transfer the heat which is good but you're, saying that it's not even a drop of the bucket compared to the amount of moisture that we're gon na want to take out of that air that's coming in is that correct. That is correct, but when we say we want to take the water out of the air, it still depends on what level of humidity we want to have inside and the fact the matter is.

We people can be quite comfortable at a very wide range of humidity levels, so absolute humidity levels and even relative humidity levels. We can be comfortable at a lot of different levels. What what are those levels like with some guidelines? We've heard in the residential market between you know, 30 and 50 percent relative humidity in the wintertime is nice. Is that the experts opinion as well and what about in the summertime? I think if you look at an annual basis, something between 30 percent relative humidity and 60 percent relative humidity would be the center of rational comfort zone for a house, that's being held between 68 degrees, Fahrenheit and 6 and 78 degrees.

Fahrenheit 68 to 78 might be a range within that range. 30 % relative humidity in the wintertime might be kind of a lower level of comfort at 68 to 72 and in the summertime at 72 to 78 degrees. Fahrenheit, probably 60 percent RH would be a, but it would be an upper boundary and we have that range. So when I say load, what I'm talking about is, if you want to keep a constant humidity level inside once that absolute or constant relative it just hast it constant, absolute okay, okay, so we don't care about relative humidity when we're talking about load, because relative is Real to temperature and squishes around it's squishy, we're talking about load and taking watery are there we have to speak in absolute humidity terms.

So if we wanted to keep us a constant, absolute humidity, then, under that circumstance we would have to take much more humidity out of the incoming air on an annual basis than we would taking heat out of the air and the mixed climate in a southern climate. It's it's much closer to the same number, but it's still maybe three to one not five to one. So there's still one heck of a lot more humidity in the air. If we want to keep a constant level in sight, but we can tolerate a lot of slop and that's what we get.

But the big point - and the reason I want to mention this - is that when there's a humidity control quote problem, unquote when it's an uncomfortable amount or an unproductive amount, or if we have moisture condensing inside of things like that, then we have to speak in terms Of absolute humidity and then the place, to put your mind, is the ventilation air, because that's where that constant load is coming from so you mentioned, we've got the HRV. What percentage of the houses in the United States have an HRV I'd submit it's less than five percent. I always gon na get one, so I don't think we have those devices in most houses. So therefore, especially when we're talking about exhaust kitchen exhaust, in particular, when we're talking about houses with no make up air system at all, with no ventilation air system at all, what we're talking about is exhaust that pulls in humid air from outside and that's the air.

That's giving us so much trouble is when we're exhausting a lot of air, but we don't replace it with dry air mmm-hmm. Someone represented an idea to me that I thought was kind of brilliant, which is to have the return plenum, be kind of a room at the bottom of a closet like a little cavity and to actually just have an outlet in there that you plug a dehumidifier. In that room and have a duct through the wall to outside, so that is the first of all. Is that a valid way to dry the incoming air in this kind of scenario? And secondly, how else would we dry the air that's coming in since we're really not, as you mentioned, not doing this at present, I that can work and it can fail miserably.

One of my colleagues in Florida he's a registered professional engineer and a forensic engineer, and he was called in for 400 Apartments, where that was the basis of the design. The idea is, you cut a small hole in the exterior wall and that comes into a plenum in which there is mounted a conventional cooling based, Sears or Kenmore, or somebody's dehumidifier mounted below and air handler, and that's the idea has that you're gon na more or Less dehumidifies return air and the incoming air blend, and that can work, but it is often problematic and the reason is because that dehumidifier may or may not be effective there is it may or may not take moisture out of the air and number two it may Or may not take moisture out of the air when you want it to the question is: how is that little guy controlled? Is it controlled with a humanist humidistat that works or one that doesn't and is the humidistat mounted inside the cabinet of the Diavel fire? So it's sensing, the humid air right next to the cooling coil and therefore it cycles on and off, or is it not an outside the way none of them are except the one that I have in my basement, which I had to modify so it didn't do That, but so there are reasons that that design should work better than it than it. Then it often has there are often other cases where it's worked. Just fine, where you have a smaller amount of loading where you have a higher occupancy, where you have people that adjust that humidity sensor in the in the diem Edifier, where you have people that actually clean the filter on the d-mat of fire.

So it gets air. Instead of just slowly, clogging with life is so complicated. Ah, you asked is that what we should do, or should we be doing something else? What we should be doing is something else. What we really should be doing is using hardware that doesn't exist and that hardware and would be designed so that it's a little miniature makeup, fair system for residences, and it would humidify in the winter and it would dehumidifier in the summer it would heat in the Winter and it would, it would cool in the summertime, and it would do it within a range of values, and it would do that in a rational way, and it would be coupled with the heat recovery ventilator, and that would be a really nice thing to have.

Okay, so I'm in I'll be an investor on blue hair project. Here this is what you're saying is that the technology exists, but the product itself does not exist. Is that correct? That's exactly correct! Why? What is what what is people's problem that we don't have, and we've got all these manufacturers making all this stuff that they want to sell to us? Well, they make something that we actually need, especially with the codes going in place like who do. I need to knock on their door and tell them that they're being an idiot, nobody, everybody is responding to rationale cues from the marketplace, how it should here that homeowners, it's our fault again.

It is because it's very difficult for a homeowner, say gosh. I don't have enough fresh air in here mm no and gee. I know what my problem is. I I have you know 45 cubic feet per minute, instead of 150 cubic for you permitted in this space.

You know it. We we don't have easy metrics that give us the visual and sensory feedback to say. I need something different than what I have, because we have a very broad range of tolerance for this stuff as human beings. You just brought up metrics, which is one of my favorite topics.

So I do you think that, now that people think the younger generation of homeowners are having on their smartphones, they've got their data on what temperature their house is that and when their furnace is running. Do you think that absolute humidity might actually get into the you know the graph there that the homeowner is looking at and maybe that metric will help to drive the market of inventing the products that they will want to buy? Well, I sincerely hope so, but that's probably a false hope in my case, Hey. I have spent us pretty close to 40 years in this industry, and I know that it's very difficult to educate people about the complexity of dewpoint versus relative humidity. So I think it's going to be a tough, so I am vaguely optimistic, well, not vaguely, and I'm more than am 30 or 40 percent optimistic that what we might have in the future is a thermostat on the wall, where you have a dial.

It's a big like Frankenstein knife switch kind of dial. You know yank it back and forth between two extremes and one says cooler and the other says drier. If you had that, instead of numbers an exactly dew point and then the system was intelligent enough to make sure that it actually took moisture out of the air when it needed to add it. When I needed to do cooling when it needed to when you when you, when you respond to your sensory, your sensory inputs, it says gosh, it's too cold in here.

You know, as opposed to gosh it's muggy in here. I better make it colder mm-hmm, which doesn't is not effective. What if we just took the thermostat to completely off the wall, and we had a voice recognition system that just listens to you complain and based on the tenor of your voice. Anyway, oh good, it needs to be a little yeah.

I think I like the idea of a physical dial that we're with with divisions but no numbers, and it says, cooler or drier home, to empower the homeowners actually feel like they're participating and to avoid focusing on the numbers, because people, if it is drier, will be More comfortable at a higher temperature that will save energy and it will make them more comfortable. Similarly, in the wintertime, if we add a little bit more humidity, we can be cooler, we can be warmer more comfortable at cooler temperatures, and that will be a good thing. So I think if we can, if we can get thermostats that respond to sensory input and get the number the unproductive numbers out of people's minds, I think that will offer a lot of improvements, but we have to have equipment that will respond to that. We can't have equipment that when you ask for dryer it makes you colder and that's some technology too.

That requires some work, so the other division that we originally opened up. This episode with is the drying of stuff. What principles do we need to know about the drying of stuff? In order to be effective, I think the most important thing about drying stuff - another when I say stuff, I'm talking about gee the carpets damp over here or gosh. Why is that carpet damp over? There is that car: where is that dog? Because yeah, you know you got a pipe leak and now you you fixed the pipe leak and I need to dry something out.

You had a problem with the air conditioning and everything got really muggy. It was either too cold or something - and now I recut this damp feeling your sheets are damp - you just dry stuff out. Well, I think that the most useful principle to keep in mind something that very fine engineer, told me a very long time ago. It says you've got to get the heat in to get the moisture out.

You have to add energy, you have to add thermal energy to a damp material. In order to mobilize that moisture the the the water molecules that are in there, you have to get them woven, you have to get them moving, so more of them will come to the surface. It also helps a lot if you happen to have you dry air. In which to put that humidity so that it will absorb that moisture and maybe move the air a little bit over the material, the reason that you want to move the air over the material is is if that air is dry, you want to do that.

If that air is humid, you don't want to do that, because if the air is humid, then you might be adding moisture to that damp material, not subtracting it. So you want dry air and then you want to move it across the surface. You don't want to move it too quickly, because you don't want to crack wood, for example, if its moist, you don't want it drying really quickly, but you do want to have air moving across it so that you can pull the human, the humid layer of air Off the, but not do it too quickly. Could you also raise the temperature of the air that's around it, which would lower the relative humidity and turn the air into more of a sponger? Is that it kind of ineffective? I mean better know that that's not a bad way to do it as long as you aren't creating some counterproductive.

You know phenomena at the same time like what like, for instance, you've got a damp area, so you're gon na heat up that area with the hairdryer or something okay. So then you're gon na mobilize that moisture it's going to come out into the air. It's also gon na be driven deeper into the building too, and so maybe it would go to another part of the building and condense there. So you didn't need to think a little bit about that mmm.

When you mobilize the moisture it's gon na go places. Tell you where it's gon na go, it's gon na go everywhere, but it's gon na stay in the areas that are still cool. Why is it gon na stay there? It's not gon na go there because it's seeking the cold it's gon na go everywhere, but when it gets to the cool area, there's gon na be less energy there. So it's gon na want to stay there.

Hmm and that's the way to think about this business of humid, air and humidity at dew point and relative, humidity and stuff, like that. You know think about the fact that when you have a lot of absolute humidity in the air or even a little bit, it's gon na go to the coldest place along with every other place, but it's gon na stay in the cold places. That's the way to think about it, not that it's gon na go there like it's on a mission to get to the cold place. It's gon na go everywhere, but it's gon na stay in the cold places because there's no not as much energy there to lift it out and keep it moving and keep it in the air.

First of all, I'm in for that all the products that are in your head. I hope that we get to hear a lot more about your ideas and see them actually come to life in real life. Lou Harriman. Thank you so much for talking with us today.

You're very welcome it's a lot of fun carbon. As always, you have been listening to the building forum, its podcast from the building form its workshop. I'm corbett Lunsford tune in next time. Thank you.

Thank you. Thank you for listening to the podcast. Thank you so much to Corbett Lunsford for being willing to allow me to Riera this episode. You can find all of his podcasts by looking up the building performance podcast and you can look up building performance workshop comm for everything that he's up to.

I highly suggest that you follow Corbett if you are willing to give him or listen to his podcast, gave him a review or just give him a review on his podcast just for enjoying what you had here. I would greatly appreciate that he's building an audience he's doing really good things to help the community, and I would encourage you to support him and what he's doing and also look at his book. His book is really really good as well. So, like really the bible on building performance, especially it's written in a way that an HVAC technician can understand in my opinion, now we're all the way here at the end, so I'm giving it gon na give you a message here.

That's just for those of you who listen all the way to the end of my podcast, and I assume that that's a reduced number from those who start off listening, and that message is that I know some of you probably hear the sponsorships. You know rector steel, testo carrier and you think what gifts you know now brian's going to start pitching products. I want to tell you that i work with companies that i use. I work with companies that I believe in and I believe, are doing the right things for the trade.

The partnerships have to make sense and with all three of these companies the partnerships make sense now. Does that mean that they're gon na get it right? Every single time does that mean that every testo tool you've ever used in every rector steel product, you've ever touched in every carrier unit. You've ever worked on it's gon na be perfect, absolutely not, but what i want to give these companies credit for is that they're stepping up to the plate to help with technician, education, and that really is at its core. What hvac school is all about.

I mean we have a lot of fun. I joke around all that type of thing, but you'll notice. We keep it positive, we keep it Pro trade and we're looking to improve technicians. That's why we're technicians first were for text by text.

Should we help out some apprentices, we help out people who are in trade schools absolutely do we help out homeowners. I hope not where this isn't for homeowners. This is for you as the technician out there in the field. I try to.

I try to do things in such a way that it's gon na be over the head of a homeowner, but it's gon na really serve the technician. So the reason why I take on sponsors is because it's a necessary part of helping this grow and helping me create the very best content that I can and when I pick a sponsor when we choose to work with the sponsor we're choosing people who have shown Their commitment to the trade and who I'm proud to represent, am I gon na, be a little rah-rah, sometimes well sure I mean first of all, because I talk about the products that I believe in, but, second of all, because I really like these companies - and I Really want to see them do well, I want to see carrier testing, rector's he'll do well, and I do I give them feedback. Sometimes it says hey. Maybe you should adjust this or maybe you could do that.

Absolutely I do. Am I gon na do that here? On the podcast, no I'm not gon na do that here in the pub, because I don't need to. I talked to the people inside these organizations when I see something that they could change or just in order to make it better. But the fact that they partner with us says a lot about them.

It really does, and I'm very thankful to them, and I'm really thankful to you for listening more than anything else, because you're, the one who makes this whole thing work, the teamwork makes the dream work as they say all right, I'm done being cheesy thanks for listening, We'll see you next time on hvac school.