The free training provided by the HVAC school podcast is made possible because of the generous support from our sponsors, testo rector seal and carrier. Alright, if you guys have listened to this podcast for any amount of time, you know that I kind of have a little bit of a crush on the test of 605. I it's just a stupendous, can I say stupendous and not have it seem like hyperbole? I'm gon na choose to say stupendous. It is a stupendous tool for the investment that you spend on it.

It is a great term, a hygrometer, and for those of you who like what the heck is that there, my grandma Gert well, tell you. If there, my hygrometer is basically a digital psychrometer, that's another term for it and measures, wet balled dry bulb relative humidity, a dew point. You know it can extract all those. If you've ever looked at a psych chart, you need a couple pieces of information.

Then you can extract the rest, but what the 605 eye does really well is that you can measure these readings in duct, so you can take wet bulb, dry bulb, relative humidity in the return, wet bulb, dry bulb relative humidity in the supply and right there. In the smart probes app, it will actually calculate delivered capacity. As long as you enter, the CFM switch is pretty cool CFM. I always want to say CFM's CFM o there, so the 605 eye is a great tool, but when you add in what Jim Bergman is doing with the measure, quick app, which you can find out more by going to measure quick, comm forward, slash download now on That application - you know, I'm excited about that product, but the test of smart probes in this test is 6:05.

I work with Jim burg and some measure quick app, and so you can get the best of both worlds. A really really highly functional, app plus the test of 605 - is that the actual smart probe app that you can use directly with a 605. I it works great, but you can extend its functionality by using it with the measure, quick, app and so getting delivery capacity. Is a huge thing and you can actually show your customer right there on your phone.

We've already done this in many occasions like look. This is how much capacity the system is actually delivering. There's what you paid for? Here's, what you got it's great product and it's also just a great way to get your indoor wet, bulb and dry bulb, which you need anyway, if you're going to calculate super heat on a fixed orphis system. If you want to use it to calculate target delta-t air temperature split, it's also great for that.

It's just a good all-around temperature measurement device. Plus it gives you that additional data that you can only get from a thermo hygrometer and you have the ability to get it in the duct plus it's Bluetooth and, like I've mentioned a million times, you can get that particular product to test. Oh 6:05, I, by going to true tech tools, calm and at checkout, use the offer code get schooled all one word: no caps, no spaces get schooled. Look at the bottom left-hand side of the screen when you're in the process of checking out there, and there is a coupon code box and type.

It gets cooled in there and you will get a great discount when beat zoom on the 10-second flame, free refrigerant, fitting from Parker reduced labor costs by sixty percent with no brazing no flame, and no fire spotter discover how Siouxland can help you be more efficient and Productive visit zoom lot, comm for more information seriously, his initials RB, o or reason Brian or hey. This is the HVAC school podcast. I am Brian, and this is the podcast that you listen to when you want to remember some things that you might have forgotten and maybe also remember some things that you forgot to know the first place. Today's episode is something that you probably don't practice.

I'm gon na bet that out of those of you who are listening, there might be a handful, a literal handful. I can hold you all in one hand, so all Lilliputians all little people out there who have actually practiced this, because it's a very cutting-edge thing. It's something that we're starting to hear more about some states. You may have it, but usually it's the different industry that does this and it is testing the envelope of the house and so that's using a blower door before you check out on me Joe.

It describes this in a really just a very good way, like he talks about it in a way that I think, makes sense to the AC technician. So I've got Joe meh who's going to be talking to us about the duct in the home that we consider the least, but we really need to consider it more. So I got Joe here and Joe is like the expert and all things: blower door and lots of other stuff, but we're thinking a lot about blower doors right now, a lot of blower door talk going on, introduce yourself. What do you do? Who are you? This is the basics yeah, I'm Joe meadow SH and I own energy environmental consulting, and I also am the executive director of a healthy home environment Association.

One of my things I regularly preach about is about why HPC contractors don't include the envelope as one of their things that they actually evaluate so we're here to talk about where's the benefits and challenge. Does it go along with that got its you just jumped right in there and we're going to town, so the duct that we don't consider is the envelope of the house. That's the title of podcast, the duct we don't consider in the duct we don't consider. Is the envelope the largest duct system in the house? Is your envelope? Let's talk about that from the get-go, so what are some things that aren't being considered? That ought to be considered, as it relates to the envelope most HCC contractors who do a great job they're designing their system.

They use a manual Jay Manuel od. All these things to tell you how much flow do i need where it is. What's the impact on the r-value, the windows orientation, all that great stuff, but one features is in your software that nobody uses is the infiltration rate, that's actually in the house and is always estimated and there's no way to really estimate it correctly. Unless you actually measure it for a variety of things, so if you're just guessing you're, definitely just making stuff up so there's other considerations, and I was actually having a conversation with one of my sales staff just four days ago, when we're talking about so much of Manual J is estimation, and this is a huge one, but then there's also things even like insulation, where you don't always know what it is, and when you kind of compound all these different things that your guesstimating, then you can come up with a pretty dramatically incorrect Answer and have you've seen cases like that, where there's a pretty incorrect answer and it's due to infiltration - that's not being accounted for yeah.

But if you look at your manual J in terms of what infiltration is, it could easily be 15 20 %, but I've seen it be on existing homes as much as forty to sixty percent of your systems requirements or how much BT as you need is on Infiltration - and it's just shocking that people just accept that and that's actually, they measure it, even if you guesstimate how leaky in the house is, you can still be. Forty percent of your load is infiltration, something that we can actually correct or make improvements on. It isn't just comes with the house, I'm not going to change your insulation, that's really a rare thing. You may add more in the Attic, but I'm not gon na change your walls.

It's never beneficial for energy, wise to replace your windows or anything like that. So it's just not a great bonus in terms of energy reduction, but you can get major energy and comfort out of actually sealing up the envelope. What you just said sounded like heresy to me, where you said that you're not gon na get any energy benefit out of replacing your windows. You mean that the payoffs not going to be there or you literally aren't going to benefit.

Neither one you're not gon na benefit, so you only benefit you get are actually from the street value. The sidewalk upgrades over that you put in new windows there's an enormous amount of research. That's been put into changing your windows, which are not a high r-value anyway. Even your solar gain stuff is minor depends on what climate zone you live in, but the actual benefits of energy reduction from windows usually has about a 40-year payback.

You can get a lot of great day back by adding sunshades or sunscreens, or something like that. Those have huge, quick paybacks, but changing your windows out for energy savings. It has been proved to be a false claim. It doesn't really actually happen.

So what we're really doing with window in most cases is we're decreasing the amount of solar radiation that comes through so the amount of radiant heat that travels through the window and the best of circumstances. But when you're in, like a high latent environment, like we are in a lot of states in the south, are they don't even other parts around the country that radiant gain doesn't add to your latent load? It's directly radiating to the space, which means it's increasing. Your sensible temperature, without affecting your latent, which in some cases, isn't a bad thing and, for example, in my house I would probably do well to leave all the blinds open and leave everything so that as much Sun could stream in. So that way, it gives you some radiant load which drives up your sensible temperature, which helps the system run in order to dehumidifies.

So there's actually some cases in which you may want some of those radiant gains. Yeah most homeowners aren't getting that or understand how that is in fact, the last thing that they think they want is to have a major solar gain on their house or their furniture or other stuff. That, then makes them feel hot. So again it may change your humidity factor and how they feel comfortable, but most people don't sense it that way.

So most people aren't really that concerned about whether there's too much sun shining or not, but back to the original point, is swapping out windows paying a lot of money for change out your windows cheaply. You could do it for maybe under 20 grand, but most people are spending more. It's actually buying a car with a long-term loan and that's usually how they kind of sell it that you're never gon na make that payment back in terms of energy savings, and maybe some comfort, yes, but not energy savings. So if that doesn't work, let's think about what does work and what is some of the best payoff so you're talking about the envelope, let's start with, if we want to plug into a manual Jayne accurate infiltration number, which I guess we're almost saying that we don't Want to we don't want to plug in a high number.

We want to fix the number before we plug it in to manual J. So if you have a house that has high infiltration rates fix that space that shell, so that way, you're not having that leakage into the space and then then plug it into manual J's, but just so we're on the same page so that we do these nice Systems or clean, beautiful installs you got great supply. Let's say we overcome the undersized returned. We've got a good supply and return what controls all of this.

It actually has to go somewhere in the house. Stay contained not get influenced or degraded by the infiltration factor. So my example was imagine that if somebody called you up and said we're really uncomfortable in the upstairs and you found out that they never close their windows, their windows are always open. So they're, like oh we're so hot in the summer, were so cold in the winter I'm like.

Well, you should close your windows and the reality is. You should seal up your envelope because these are major issues, especially in a hot humid climate, where your attics get people like. Well, let's just say it's a hundred degrees outside your attic is 140 degrees, so that air leakage is coming in. So people who have a two-story house they realize they're upstairs is always hotter and it's because of infiltration and that's a major thing that is correctable.

So how do you do me? No Jane! You only get these six five choices. Tight semi tight, average semi loose loose that doesn't really quantify. In fact, if you lay on an older house and you just picked loose you're, probably only half of how leaky the house is well, there's that and there's also the fact that getting the manual Jay right. So that you currently size the equipment, you want to do that once you've fixed the duct, that's leaky, and so in this case the leakiest duct is the house itself so fix the leaky house and then test it.

So that way, what you're plugging into your manual Jay is actually a good number as opposed to a bad number or realize that you should be at least sizing the equipment correctly. So you now realize that the 3-ton out is not a three-ton in anymore, because I know how leaky the envelope is and how much infiltration impacts this system amount. Now I need to go to a 4-time which it didn't need, but some people would rather do that and go I sized it correctly then actually fix the problem. All right so now, let's go into is the first step is to test in test the conditions that you find when you arrive.

So how do you do that? I saw the blower door is a simple concept. It's just a large calibrated fan with a gauge. So you seal up the house and we'll call wintertime conditions or closed house conditions. All the outside windows are closed.

All the indoor inside doors and closets and all that stuff is opened up, so I basically have isolated inside outside and now I run the blower door and the blower door is a very powerful device that will measure the amount of pressure inside of it and determine For you all back to the same concept, how many CFM is this house leaking so based on the volume of the house is how we kind of do it as a process. The volume tells me how many air changes per hour. I have this house. It tells me how many times a recirculating while the blower doors on and we can compare everybody's house - it's just a common reference to do that.

That's 50 Pascal's negative when we depressurize this negative 50. So I have negative 50 Pascal's and I can say: oh this. Many CFM, divided by the volume times 60, gives me an actual air changes per hour so and because I was talking to you about this a couple days ago, when I first heard about it, I'm like oh man, how do you calculate the cubic feet of air Inside of a house easily, but then you told me that it really isn't as complex as I wanted to make it most. Homes may have one or two ceiling heights and but there's no vaulted ceiling.

It's pretty straight for that. I can just go in and be like well most of it's all eight feet or it's all nine feet, except for these one areas, and I can do a square footage times. Eight-Foot plus the master bedroom. Is this much with an additional foot on top of it? So cathedral ceilings or whatever you just kind of create a process, and the best thing you get is a really good laser measuring device Bosch makes one disto makes one's a little expensive, but for 200 bucks you can get something actually calculates the volume as you go, And technically, if you want to follow the nancy standards, they actually recommend you you're measuring the outside of the house, which can make it easier.

Sometimes the garage can be a challenge, but you actually can measure the outside outside house. That's actually where the air barrier is or that's where the envelope ends is telling you the outside of the house. So that's actually a standard you can measure inside is fine, but the more volume you get. The better air changes per hour you end up with, but if you measure the outside of the house and then you just subtract the garage, then that gives you your yeah, that's right, where I show or add X and then obviously we have an attic and address The volume inside so there's multiple ways to measure, but the point is you are just trying to give it up measurement to confirm that I'm within a plus or minus.

That gives me a reasonable results that I could live by right and it's just not at the point I was wanting to me when I was initially thinking. I'm thinking, okay, I literally have to go to every single room measure, every single room, every single closet, but it's not necessarily bad right. So the process is blurred or depressurizes the house down to 50 Pascal's and that it's measuring the CFM leaving the house. You then calculate that with the square footage of the house cubic feet of indoor space in the house, and then that tells you what your air changes are per hour correct.

That's right! So, while the blower door is running in order to get any kind of measurement, there must be leaks in all homes leaked and I can easily while the blower is running and find this leakage in the house a lot of times. You can just find it with your hand. You can actually feel air blowing out of your switches, your receptacles in all these kind of conditions. So that's not the problem.

The problem is: where is that actual switches in that junction box connected to the outside? Usually it's the attic or, if there's a crawlspace, the crawlspace or combined, but your goal is to then make an assessment as to okay, I need to go find where it leak, don't put the gasket over the receptacles, because somebody cut their arm off and you put A couple band-aids on it isn't the solution. You need to go to the source and correct it, which is somewhere where the envelope begins, either above or below that. Usually it's the Attic. That's got a big hole for a small little wire.

All those need to get sealed, your drywall doesn't actually contact all the wood. So it's leave these little gaps. It all add up to large infiltration that happens and creates pressures and allows hot air hot air. You guys are free savvy with your understanding of science on how it works with air conditioners.

Hot goes to cold. That means that my hot attic air always wants to come down literally into the walls and into these areas and shows up, and these areas that clearly impacting comfort, yeah and that's an important consideration, because some people will think why would your house be negatively pressurized when You are conditioning a space, you are creating a negative energy environment, you're creating an environment in which you have a driver, and that driver is all this hot moist air wants to make its way into this cool, lower relative humidity space that you've created - and, in that Case we're talking about the cooling season, but regardless you don't want to have situations in which either energy is escaping your home or entering your home and you're always going to have that driver, no matter what you do all right. So you mentioned a couple of the common things that you seal at that point. But how do you find them you mentioned? You can do it with your hand, but what are some of the other ways that you can find the spots that are leaking in again, we'll go back to the blower doors active, it's running you can hear in the background it 250 Pascal's, and I can now Separate my gauge from the original location at the blower door, and now there is these devices that all manufacturers sell, or you can make your own just got a pressure pan and what it does.

Is it measures the pressures with the gauge. So I know well Steve Reardon Arden he's actually got some nice videos out there that are showing how this process works. So I now have these pressures that are moving in so if I've 50 Pascal's coming into the house that I can now measure all these locations where that is so, you can put your pressure paint around the receptacles or over a can light, or even over the Duct system and measure these pressures, so a rule of thumb, is anything that's connected to the interior part, which means switches receptacles. Even your exhaust fans, anything above 5, Pascal's plus or minus, is connected outside.

If it's above 10, you probably need to figure it out and solve it if you're closer to 50 you're outside all right, that's the concept so closer! I am 250! I'm outside duck test is a little more tweaked. So you put your same pressure pan over your duck system, which again anywhere where you cut the drywall, which is your most common air barrier. Then that becomes your air barrier. Imagine that the duct system, I cut a hole, I put a grill in - and I got my duct in there and now as it moves up into the attic it's the air barrier.

So if there's a big hole in the duct system, clearly I get air coming in directly from that part of the duct, and I can measure that and determine that there's leakage in my duct with the blower door. So the pressure pan has good analysis of leakage that are connected outside with holes in the attic holes in the crawl space, but also holes in your ductwork. It's a very simple device to do this. The rule of thumb for duct testing is if it's above 2 Pascal's, then you really need to look into this.

If it's about 3 to 5, you've got issues if it's above 7 or 8. You've got significant leakage. In that run, it is civic to that run. So it doesn't mean I got leakage anywhere like a duck tester does it says? Oh I put my pressure pan on this one supply in this one bedroom.

I know that if it's measuring 8 Pascal's, I know it's between this boot and the main trunk somewhere is the leakage and it's very identifiable. I can actually locate this. It's a great tool for locating duct leakage very interesting, so it is different, though, so it's good for finding kind of a general view of your duct leakage, and then it gives you sort of a pinpoint specific and it's more proximity. It's not gon na give.

You necessarily exactly, but it's gon na, give you a good idea of what general area. Yes, I know that it must be near that trunk and near and somewhere between that trunk in that boot, you don't need to go roaming all over or looking at other trunks. It's in that section is where this leak must be, or it's near that trunk, where that took take off this, so doing it with the pressure pan, though in the blurred, or it's not like a duct leakage test for that specific deduct leakage, because it's not gon Na spit out a number and tell you, this is exactly how much your ducts are leaking, but it is gon na give you a good general idea of what's going on, you think of it as a semi-quantitative test. So it does give me a number.

So I do get something, so I'm not just guessing that I have pressure. I don't know what it means. So I do have a number, but it's not a quantitative in terms of how much CFM I'm leaking. So your doctor says you're leaking this much CFM, but you're leaking anywhere and everywhere.

The pressure pan says: oh you're leaking in this area. I don't know how much, but it's a significant enough to check. So somebody who does do both if you can do a blower door test you get bored or on you, go around and check all your ducts, and I can tell that if I do have a lot of leakage, I know where it came from. I know that these two back bedrooms they were measuring seven and eight Pascal's.

That's a significant pressure difference. So when I do my duct leakage, I'm like Oh first place. I want to go to or these two back bedrooms, because I know that my pressure paint indicated that they were the leakiest all right, I'm here with James Bowman from rector seal and one of the new products that I like that rector seal makes is the dissolve Kit dissolve without an e at the end, so you're making use of the dropping a vowel at the end in order to be able, along with the hip kids, so tell us a little bit about dissolve James dissolve is a product that we developed specifically for mini Splits we developed dissolve is two coil cleaner. It's really an awesome call cleaner.

I mean I like it. I've used it for other things. It does a great job of cleaning outdoor units and indoor units as safe for the plastics and the board will safe for the coil safer, our pumps, it's odorless, that's another thing that I really really like about this product is what we found during our testing. We're development is that even a pleasant smelling citrus smell when you're in a 10 by 10 room can overpower you if you're trying to clean up the unit, so odorless is important and then from there we went on to develop the cleaning kit uses a disposable bag.

Some people say: what can I reuse lately? Well, yeah, you can reuse it if you want to, but if it rips the second or third time it's on you, but also we made it disposal. Because can you imagine you drain all of this nasty, cleaner and dirty water and all the crud out of this thing and then you're gon na take it home, take it into your shower and clean it then! Hang it up and dry it and fold it so that when you use it again next month, it doesn't look like something you dug up at the cemetery, so it throw it away. The bags are less than ten dollars replacement bags. The kit includes a gallon of our cleaner, the cleaning frame, two bags a brush and a nice bucket.

The bucket has a gasket ratcheting lid. That's another thing: it's nice, if you're in somebody's nice, home or office and you've got a couple gallons of nasty stuff along with everything else in this bucket, you can put lid on it. It seals so you can carry it out of the space without worrying about leaking if you have to carry it back to the shop if it gets bumped over and doesn't leak, so we even went to for us to make a good bucket for it really a Thorough way for cleaning blower wheels and mini splits, we've ever had to clean a ductless fan, coil evaporator, coil, blower wheel. You know how nasty it can be and the dissolve kit from rector seal is a great product to help make that job easier.

So now what are some of the most common things that you are doing remedial II? So if you have a contractor who says not only am I going to test this so that I get my manual J straight, but I'm going to test it, and if I see a problem, then we're gon na fix it. What do they fix? Generally? The concern about fixing is a two-fold and one of which is: do you have gas appliances and where are the gas appliances, so we indirectly kind of ignore the stove is in general. But if you're doing combustion analysis, you need to make sure your stove isn't an issue. The tighter you make the home the more these combustion risks happen in the house and you become somebody who created something that was ok to have in the house or near the house.

Now you allow a lot of car oxide or other contaminants to get into the house or stay in the house. So, even if the garage is where your hot water tank is, one of things you can do at the blower door is determine how connected that area is with the blower door. You're gon na isolate the connectivity. So before you do any of your air sealing or even sealing up your returned leakage that I need to make sure that my combustion appliances are working correctly seal the house and normally it's a top plate issue for the how to gets the most common places.

Chases are the number one issue: they got a huge opening that allows you to look down inside the house, fireplace chases all this areas, all around the fireplace where you can look down and see the actual drywall. That means that there are major infiltration source. So all that needs to get sealed up there using some type of fire rated material in the attic and a lot of a spray foam to seal up the top plate. So that's number one and then again confirm that your combustion appliances are still drafting.

So this is the thing that everybody says: it's like the most commonly repeated phrase. Whenever you talk about sealing a building of any sort, people say: well, you can get a building too tight, so good. So yeah you tell me it depends on where you don't mind. Breathing your air from because you're, probably living in a house or maybe in your car, doing this concept when you get back to your house, evaluate where your air comes from.

So you turn on your exhaust fan in your bathroom or whatever, even your kitchen, which is very powerful fan and air in you goes air out, that's fundamental to trade school day one. So where is the air coming in from I pause there? So I want people to visualize that it must be coming in from somewhere in your envelope around the bottom plate through the walls around that receptacle from the attic from the crawlspace. All those places are just nasty nasty places. So that's where the air is coming from.

Now, okay, so if I can reduce that, then I can make it tighter, but I now need to make sure that I am having a replacement. Don't like the phrase fresh air, because I don't know where it comes from. But I do need for the occupants to breathe more air, that's a commercial concept, so the residential is still trying to figure that out. So I need a ventilation.

So you must have good ventilation if you're going to seal the house up to another level or just good ventilation period. So I know where it comes from and that it was considered clean air and it's controlled, and I can actually account for where it came from. It didn't just come through the wall in some random lack of area that just was least resistance, location yeah. At this point we know that now, ASHRAE and ASHRAE 62 is kind of telling us that nari and we need to think about outdoor air.

We need to think about bringing in outdoor air even in residences, but in many cases we're gon na go to retrofit applications where there has been no consideration for outdoor air and essentially what they're saying when they have no consideration for outdoor air is that. Well, we know the building's leaking and we're not worried about controlling it. It just is what it is, and so you just pick a leaky tight, very tight whatever it is, you just pick it off the list and you just go with it. Whereas now, if you are sealing a space and you're sealing it fairly, hermetically tight, that's a good thing, and it's something that we do want to do, because we don't want those undesigned paths, but we do need to create a design path and, depending on your climate Zone and the particular circumstances of the space you need to be then adding in some outdoor air that's going to be treated in some way, and these would go through a HRV under an ERV or a supplementary dehumidifier, or something as well as some filtration, to ensure That that air is cleaner than what it was before in better condition, this is the number-one topic in the 90s we figured out and resolved insulation there we go okay, we got that down so now in the 2000s, we're starting to do ok, codes more focused on Air sealing and better HVAC, and now we're going to the last stage, and that is that, how do we do that elation? So I do think that once we kind of get this last phase down, all of our homes will finally be the superior homes that they should have been for quite a long time.

So, for some reason, builders, HVAC contractors - everybody is just terrified of installing this replacement area and I understand the concept like. Why should I seal something up and put a hole in it, but the reality is you're sealing up the environment to control that hole. So there's always a hole: it's not like you're denying there's ever been a hole. The reality is, I just now know where that hole is and what is doing, and I can turn it on or off as I need to or make sure it's filtered and control.

Where it actually dumps this moisture and that's actually the challenge so Florida and the high moisture South climates are a significant challenge to do this. There is no ready-made solution. You really got to be on top of your game to do this, so there are some things that are out there for manufacturers or you do need to be working well with a design that has dehumidification immediately otherwise you're just dumping high moist air into a cold Environment and that doesn't do well in terms of creating some type of fungal growth, so your goal is to avoid that up north, it's less of a challenge because they have moisture issues, but nothing compared to what's down here. This is actually I've been down here for the last mini-monster encode training, and I am aware of humidity.

You guys are on another world with about humidity. You have to overcome down here. Half of what I think about in day-to-day function of our business is moisture is latent load. I mean it's just a huge part of what we do, even when you see what comes out of the ends of our drain lines compared to other places.

It's just there's crazy stuff in our air and a lot of moisture. So that does make a particular consideration, but I think you're right in that, just ignoring it and saying well the building's leaky that doesn't help anybody. So that just adds insult to injury. But I do want to mention, because you kind of briefly brought this up about gas-fired appliances - is that you may have situations where systems were installed in buildings, where they didn't have proper consideration for combustion, air for having appropriate combustion air, and now you seal it up And you don't have proper draught and you're, not providing it with the necessary oxygen, because you don't have designed combustion air, which is another side.

I think there's a lot to be said for direct vent appliances. When you are going to this strategy of sealing the space fairly hermetically yeah, it's been to where those appliances are especially the older furnaces. But the hot water tank is still a natural draft appliance and that's one of the most challenging ones and it's very expensive to go to replace that with something. It is direct draft.

But it is the goal: if you really want to have a high-performing home, a better home, a healthier home, it's really the realities. What clients want, don't assume that they won't be willing to pay for that, and you can show them. Why well kind of go back to briefly the blower door that you can actually make determinations on whether or not your attic or your garage is connected with the same concept of pressures that are similar while the blower doors on? So I can tell you if your garage had leakage direct leakage to the garage, which means that you would have direct leakage from your combustion appliances. So all those things also backdraft.

It takes less than five Pascal's and most HVAC contractors live in inches of water. In a column, so 249 Pascal's in one inch of water column. So that means it's a fraction of a fraction of an inch of water column and it just tastes so little too backdraft that kind of appliance and that can be done with supply leakage in your ducts. If you have excessive supply leakage, you can actually backdraft a hot water tank.

So I mentioned earlier that you may go up and find that somebody had a major leak in their return system all right and once I go to seal that, then my supply leakage may be greater now in terms of being balanced or what's no more dominant leakage. So if I correct a supply of my returned leakage, now I supply leakage is actually greater. It means it will put a more negative draw on the house and on those combustion appliances. So duct leakage is a significant risk and it's not always just sealing it up and realizing.

I've done a great service for my client. But you need to be very concerned about where those combustion appliances are so yeah pay attention to the largest duct in the home and your structure, which is the envelope itself and maybe start you know what we're gon na do. Is this winter, when you know we're slow in the winter, so we're gon na get a blower door and we're gon na start experimenting with it on sales, calls just actually doing the blower door test, doing the pressure pan tests and just seeing what we get again. The point is, once you do this you're gon na start kind of going down this road and you're gon na find that there's other things that sort of interconnect.

But the goal here needs to produce a situation where all of the year that we're bringing into the house is coming in through well-designed paths it's being properly treated and that we're consistently only putting the house under negative pressure whatsoever when we have no choice. Well, obviously, someone turns on a 400 CFM kitchen exhaust. It's going to be a little tricky to deal with that, but there are strategies that can be used. I mean you can bring in the exact same amount of air that you're putting out if you design the system properly and again.

These aren't things that people are typically thinking about in residences, but they've been thinking about it in commercial applications all along, because it really only makes sense. One of the things that is hitting are the ventilation and exhaust market right now, it's the ability to turn on your exhaust fan in your bathroom, even in your kitchen, and it actually triggers something that also then does a supply balance. So you can actually get balanced ventilation through some very minor upgrades or using some of your existing installs. You've already got so there's a variety of new switches that are out there that actually can trigger the supply to open up and again make sure you're controlling your moisture load.

But you can actually get a balanced ventilation without trying to install a new, ERV or HRV. So there's a variety stuff out there that Brian I are gon na try and tackle this fall and winter as to specific for the florida requirements that are out there and other people have these same kind of issues that they want to understand. So our goal is to be like: how can I install ventilation - and one of these at Florida just stepped into? Is they just adopted a new code and their new code is blower? Doors must be less than seven a pretty easy number to hit, but if you're below three, you now then need to install mechanical ventilation, and they were thinking that all hardly anybody will be that tight, but they're, realizing that a lot of homes are below three and That means that I would find out within a matter of days as a contractor, that they did the blower door and we're closing. In less than a week.

I needed to go and saw mechanical ventilation, and I have a week to do that and that's not really a place you want to be in so right be ahead of the curve, if you're a contractor down here in Florida yeah, when you say three and seven, You talking about air changes per yes! Thank you. Yes, right all right! Well, thank you so much appreciate your time and I'm sure we'll be having a lot more of these conversations in the future. Oh, very quick, plug out retro tech, a little bit oh yeah yeah. So I read check is my main client and if you're really looking for devices that you really want to have in your arsenal of great functioning and user-friendly gauges, you definitely ought to go to our retro tech and we also have a concept called our cloud which Automatically does your testing and logs all that data, so red check comm is a place to go.

You will not be disappointed with that type of investment, so it's retro tech comm, but it's not. The tech is spelled only with a C. So it's retro Tec comm, because I'm in mistake, Newington, actually spelling the word tech out and then, when you talk about misspelling of words, you can go to true tech tools. Comm, which is true, spelled t ru tech tools, comm, and you can find the entire suite of retro tech products there and, as always, if you're interested in something you can use, the offer code gets cool to check out for an 8 % discount.

So thank you. Joey, I appreciate your time and we'll talk again soon: hey Brian alright. So thanks for listening thanks a lot to Joe, I got to spend a little bit of time with Joe he's a really great guy, very entertaining gentleman very interesting dude and I'm very thankful to him for stopping by the office and recording this, and I do think This is a piece of the industry that a lot of you would benefit from learning more about. So, if you want to know more about all this kind of world, I would suggest going to the building HVAC science podcast, which is a member of blue-collar roots.

Also, I'm Zack co2 from the HVAC shop talk. Podcast does a good job talking about airflow. He recently actually did a series on duct work that he talked about on the and so then she is a couple small clips on the tradesmen, a small little episodes where he talked about designing duct work. So there's a lot of different podcasts in the blue-collar roots Network and you can find them all by going to blue-collar roots comm.

I want to take a quick second and just thank carrier and carriers been with me since I started my business back in 2005 and and really my relationship with carrier predates that. The main reason why I wanted to sell carrier when I started my own business is that I had such a good relationship with their training staff. There's a guy by the name of Ray Johnson and I used to go to his classes and Ray was just a no-nonsense, blue-collar guy and he would just tell it like it was and really smart taught me a lot about air conditioning. And I like that about carriers that yeah they're a big corporation, sure they're a big business, but they seem to always care about their research, development and technical side of their products.

It shouldn't they advertise. Everybody advertises every name heck. This is sort of an advertisement. I guess, but it's an advertisement that comes from a caring for the core functionality of the product, and I've always appreciated that about carrier.

Everybody has bumps along the road. Everybody has things that every business has things that don't go perfectly from time to time, but I'm still glad that I'm a carrier dealer I'm proud to be a carrier dealer we're doing really well selling carrier equipment this year and and I'm really proud of how they Handled the green speed recall, you know they actually voluntarily came out and said: hey look, nothing's happened yet, but we've noticed some things. So let's recall these boards and replace them, and I thought that was pretty good. That was a seamless process.

They treated me. Well, they always have treated me well, even when I was a nobody when I think I think my first year in business, I sold something like I don't know, fifty thousand dollars worth of units you know which is well below what you should sell in order to Do carrier equipment, but they work with me and and I'm thankful to them, for that. I'm thankful that they're partnering with HVAC school to once again just invest in training of technicians. The same thing that brought me to carrier in the first place and made me choose to use them, is the same reason why they're partnering with us on HVAC school, and I certainly appreciate it.

So what did the grapes say when it was stepped on? Nothing it just let out a little wine we'll talk next time on HVAC school thanks for listening to the hvac school podcast, you can find more great HVAC our education material and subscribe to our short daily tech tips by going to HVAC our school comm. If you enjoy the podcast, would you mind hopping on iTunes or the podcast app and leave us a review? We would really appreciate it. See you next week on the HVAC school podcast.