We measure pressures a lot, that's what we do a lot. So when we use a a manometer and we measure static pressure, you notice, what's in the word, airflow is not in the word, it's static pressure. So let me ask you this question. This goes into what we're going to be talking about anyway, which is why i'm fine going off on this rabbit trail.

What is better low static pressure or high static pressure in terms of the system airflow, which is better, which tells us that the system has better air flow, low, static pressure or high static pressure, lower static pressure, and everybody knows the answer to that question - is lower Static pressure, that's what you want right. What is the static pressure of the system when it is off lower, so that means we have great airflow when the system's off right, hopefully you're getting where i'm going with this, what happens if you set up your airflow, you have a variable, speed air handler. Let's say it's a carrier: it doesn't really matter what it is. Let's say it's a carrier and somebody lands the yellow wire on the y1 terminal, rather than the y y2 terminal.

Anybody ever seen that happen before that never happens. Never, of course, happens all the time right. What happens when they do that you have low airflow right. What's your static pressure low, so you go up to it? You're! Like oh look.

I checked the blower charts. I measure my static pressure and this thing is working. Amazing, it is pouring water out of that drain like nobody's business right. It is working.

I've never seen a unit work as well as this one look at that the water's coming out of the drain and it is cold as ice. The only problem is that it keeps freezing up all the time and it's not cooling the house very well. So what's the what's the issue there? Well, the issue is the only way for us to know that that happened was either one catch. It just notice that that's how it's wired and be like oops that wire's the wrong spot.

Now, it's! Oh hey! Now my static pressure's high! Now i have bad airflow. I had a good airflow before now. I have bad air flow because now my static pressure's high or we could use a device that actually measures system, airflow and the only device that measures system airflow currently is, and i'm not trying to sell this product. I do not have a sponsorship, but i got to say this because sometimes people believe that i do does anybody know what it's called? It's called the true flow grid right and does the true flow grid measure air flow? The answer is kinda.

It doesn't do it directly, it uses an actual pitot grid, an actual pressure measurement grid, but it goes into the filter slot and it measures an average measurement throughout and you're gon na get in general about within plus or minus six percent. I think is what they say, which plus or minus six percent on an airflow measurement is like angel singing right everything else. You've ever been doing to measure airflow if your plus or minus 20 you're doing pretty good so plus or minus six percent is pretty doggone good. You could use that or you could just be good at catching all the problems that could cause the system not to be producing the airflow.

That's supposed to produce because static pressure alone is reliant on the airflow output of the blower and if something is wired wrong or if the blower motor is programmed wrong or if somebody put in an aftermarket motor or put in a different size, blower wheel or if The blower was dirty or who else knows what's going on with it? That's not going to be correct, so the point of what i'm saying is is that it's not to make you feel bad or guilty, because i hate it when people do that. It's to make you aware that a lot of times we have false confidence. We have confidence that we ought not have, and especially when we're trying to teach a new person, because we kind of know we're like well yeah. I know i mean i know.

Of course. I know that i got to first check and make sure it's wired right. Of course, i know i got to check and make sure the thermostat set up properly. Of course, i got to know that you know the wires on the dh terminal and they don't have the someone didn't pull the pin off and now it's running low speed.

Because of that, of course, i know that if i don't have a g call on this brand, that the thing will go down to 50 super dehumidifier mode right that happens. That's the thing that a lot of people don't know, but the guy you're training doesn't know all that and if we just teach him static pressure, 0.5, equal good, .9 or 1.7 equal bad right, we're missing something in the story all right. So we're going to talk a little bit about installation here, and this is not because some of you'd be like well, i'm not an installer. Now most you probably aren't.

Probably don't do a lot of installs if you ever are in central florida and you happen to find a system or you're staying in a house say a vacation house, because we do a lot of vacation homes. It's a good chance. If you stay in a vacation home in the orlando market, you may be conditioned by an air conditioner that we service. But if you find one that i installed, my name is on the sticker.

Then just ask to move to a different house. They'll say: what's wrong: you'll say it's just the air conditioner's not right, and i just need to move so um. So i am not a good installer. This is something that i want to just be clear about, and it's not because i don't want to be a good installer, but i think my like my head's crooked or something because i just can't i just don't make things look good and it's it's bad.

So i want to be clear about that. First. Well, we're talking about install best practices, even if you're, not an installer, you probably have some say in leading the install team. You probably can give feedback on it, and you probably have to correct a lot of problems for things that are going on from the install team.

So this is why we're going to talk about it, we're not going to spend a lot of time on any one thing, but we're going to kind of kind of go through it. But the first thing is: let's say that you really are doing a install from scratch. Anybody here do residential new construction, anybody, residential new construction, not a whole lot commercial, new construction, anybody a little bit here there. I think you guys just don't want to raise your hands about anything.

Is anybody here? You know living breathing above three feet tall anybody, anybody here, no wow! We got 40 on that. Okay, all right, i'm out the pre-planning planning post install these are areas that often get missed and we just go straight to demo and install right that just goes straight here. You know. Mrs jones needs a new system.

Let's start tearing her out right, but a lot of the most important work happens in these other things, and so, when we say pre-planning versus planning, what i really mean is the stuff that happens before we show up on the site to do the install versus the Planning that happens the day that you're at the install - and this could be residential, new construction, a project, a commercial project sitting or doing a roof pick. It applies to all of these things. If you're missing these, that's where you should do some work. First, all right! So pre-planning, you know load calculation, all that kind of stuff.

I am agnostic to anything, but just getting a result that works for the customer, which means that do i believe, in models like manual j manual d manual s, these sorts of things yeah, because they've been used for a really long time and the people who made Them are much smarter than me, and now it's all backed by software and it's pretty good. Is it always good? No is, what's that what you put in it it is, it depends on it's garbage and garbage out. That's true, but are there cases where tribal knowledge can be married with your manual jay? Yes, and i am fine with that, there's some certain things where it's like look. It says that on here this is the calculation they're using, but for our market.

That's not what i'm seeing so long as you're being really thoughtful about your results, because in a lot of cases we can be pretty biased about data, because we had that one really nasty job where we put it in and we did it by manual j and The customer's unhappy and we ended up having to tear it out. We lost a bunch of money that one job becomes really big in our head and we're like look forget it. I'm just doing 500 square foot per ton from now on, just being done with it right don't do that, but if it's well educated, it's not emotional and you're like saying look, there's some factors here that aren't being properly accounted for an example would be. Anybody knows like ashrae, 62.2 ventilation, air standards.

Those standards were not made with the southeast in mind. They did not make them with the southeastern mind, and they know that everybody's clear about that at this point, and so just following it blindly like. I must follow the standard like that's, not the right thing to do, use some tribal knowledge to give a result in your market. That's going to work out there, but that doesn't mean take the baby and throw it out of the bath water and say: models are garbage right manual, j manual d manual, ass and the softwares that support those software.

The those systems are really good. If any of you do duct designs and you actually do them like real, do them not like scratch them out, you know on a napkin type of do them um. I would definitely suggest that you look at quick model, spelled with the k, uh 2ks. I think i think it's kw.

I think, because it's a it's a 3d modeling software, that's actually built on a video game platform, the guy who did it russ, king and his son again, they're, not a sponsor! Nothing like that. It's just really cool what they've done and for those of you who have always struggled with like. Why is this so difficult like all these numbers and stuff? This lets you just like stack blocks and then it does. The manual j manual asks manual d.

All that, for you go through your supplies, i mean this is another big one before you get, you know so do pre-meetings go through supplies. Don't you wish? If anybody who does do bigger projects, don't you wish that the contractor would bring you in earlier in the design process? So that way, you could say no, that closet is lined up right on a truss, and i cannot put this piece of equipment there or where do you expect me to run the ducts between floors here? There's no channels for me to run the ducts. Don't you wish they would do that we can do a version of that as well, when we have projects that are upcoming um, where we sit down with the team and say hey what challenges we have in here. Let's make sure that we're planning what do we do wrong? What can we do differently? Those can be really quick, but that communication is key for those of you who have worked in organizations where communication is poor.

You know how much that can mean. Can i ask you about the equipment you're selling in florida or you do a lot of single stage low sear sure i mean when you say low series, there's a decent amount of 14s here sure but moisture issues. Am i having moisture issues with them contractors now talking to builders and trying to upsell them at least two stage or variable speed equipment because of molding? You know issues what so? What do you see in florida, even in florida saying florida is like saying you know like it's like saying california, it's like well the climate in california, it's like the state's this long and it's got like 20 different climate zones and florida's actually kind of similar to That - and so you know, coastal in miami versus tallahassee are two totally different creatures. Do we have more moisture issues with single stage? I wouldn't even say that we necessarily do, but that goes down to the types of houses those go into.

Those of you who work on higher end structures. You know that often higher instructors are built worse than simple houses, because simple houses, the problems get caught quicker and even you can catch them, because a lot of these issues are envelope problems. To answer your question, if you put everything in the mix, i get what you're saying we're not necessarily seeing more issues with single stage than we are with multi-stage. But if you kind of control for the fact that yeah do multi-stage pieces of equipment, if they're set up properly, do they perform better yeah again, depending on which one you're selecting? Because this is another kind of tricky thing, we actually took some some two-stage equipment and checked the sensible heat ratio.

This is going we're not even going to talk about sensible heat issue in this presentation, but we looked at the sensible heat ratio of the low stage versus the high stage and even though the system is running longer when it goes into low stage, it's actually doing A worse job of dehumidifying, if you've ever seen the sensible heat ratios or measure the sensible heat ratios on ductless systems. This is a dirty little secret, because they'll say manufacturers will say everybody will say this is getting better. So this isn't always true, but but for a long time it's been, they would say these systems. Dehumidify amazing, look at the statistics on they dehumidify.

So well, that's true when they're at full speed, but when they stage down yeah, they run longer, but the sensible heat ratio starts. Cr, creeping up and sensible heat ratio simply means the amount of the energy. That's going towards sensible heat, i.e, not moisture versus the amount. That's going towards latent heat, so for our markets, lower shr equals better, even if it's more than it needs to be go ahead.

We put many splits in basements right, very little low for cooling and need to be unified, but it's raising the cold temperature when it's barely engine long. What's the solution there? Well, the solution is to not put ductless systems in basements i mean that's, not the answer. Um, unless you have a ductless system that and again i'm lumping all duct systems into one basket. That's not true! There's large variations and all of the major ductless manufacturers know about this problem and they've been telling us they're going to fix it for a long time.

But let's back up, this is one of my favorite topics in the whole world. So sorry that we got off on this, but why do you think ductless manufacturers do this? Why do they do it? So for those who don't know how what happens? Here's? What happens? You start up a ductless system, you wire it up and fire it up. That thing is draining like crazy. The space is coming down.

You think everything's great, this thing's dehumidifying great and the answer is it is, but as the set point or as the indoor temperature approaches setpoint, what does that system? Do? It takes the compressor and it spins it slower. Okay, super simple: it spins it slower what happens when you spin the compressor slower it moves less refrigerant right when it moves less refrigerant. What happens to the head pressure goes down right. What happens to the suction pressure goes up.

Compression ratio drops. What does that do to the system? Efficiency makes it go up. Those of us who are like hey, i love these ductless systems. What do people say about ductless systems when they're trying to sell them? I love these ductless systems.

They're super efficient right, 30, seer right. How do they get that 30 seer? They get 30 seer by spinning the compressor slow right. Do they drop the blower speed when they're spinning the compressor slower, sometimes a little bit, but it's not proportional because the controls are often independent of each other. The two aren't really talking that same way and the customer can go ahead and jack that thing up to high speed all the time.

If they want right. Oh, i want it to cool, better, put it to high speed all the time. So what happens? If that's the case, compressor spins slower efficiency goes up, but evaporative coil, when the suction pressure goes up. What does the evaporate coil temperature? Do? It goes up you get a warmer evaporator coil.

Is that good or bad? It's good for efficiency? It's bad for dehumidification, to the degree that there is a model match with our friends from mitsubishi, which they literally are my friends. They are a sponsor of my podcast and of my show, and i'm going to throw them under the bus right now. There is a model match in which the sensible heat ratio is one. Do you know what a one sensible heat ratio means? That means no moisture removal, zero right.

They call that the arizona they call that the arizona model right and is that bad? No, it's not bad, like you said. If it's in arizona it's good right, you want, as close to one sensible heat ratio in arid climates, because you don't want to pull moisture out of the air you probably won't anyway, but in our market. That's a major problem. So here's what you do you choose ductless systems based on a tested, sensible heat ratio, value at an unloaded condition.

Fancy words means when the setpoint temperature and the room temperature get close together. We're still running just make sure that it's still got a good, sensible heat ratio and using something like measure quick, that's actually very easy to do very easy to do. If you can find one use that, if you can't then you're stuck with using a whole house, dehumidifier, probably some type of dehumidifier in conjunction with a ductless system, or you could use something like the sd-12, the santa fe st-12, which it actually cools a little bit. And is a dehumidifier, it does both, but you've got it.

You got to select your equipment appropriate to the situation. The idea that the manufacturer and the manufacturer's rep and the sales guy is going to do that for you they're just not and they're, not trying to yell they're, not trying to lie to you. They just don't know a lot of them. They haven't thought through these situations.

Some do uh um yeah yeah i mean they have. The the whole unit starts to condense. Basically um the blower wheel gets down to temperature. I mean, if you think, about the position of that blower wheel.

You ever wondered why they get so nasty dirty all the time, because they do condense and you know they do because sometimes those suckers will flick water out at you. And that's because that blower wheel is just sitting there just inches away from the evaporator coil. Like inches away from us right there and radiant heat is a factor of distance right, so that blower wheel is going to become nearly the temperature of that evaporator coil in a lot of cases wherein it will condense, especially if the evaporator coil is not pulling the Moisture off like it should you know like it's just yeah, it's challenging, you don't look to me for prescriptive solutions like here's the way to do it, but i am a very big fan of integrating whole house dehumidification into human climate designs. Anyway.

I think it's the way we should have been doing it and then but then people say, but we have didn't used to have this problem yeah. But here's. The thing you don't realize is that people used to open their windows. For you know, 10 months out of the year and just deal with it, you know we used to just deal with it.

People don't deal with nothing anymore and the houses are super tight, which means that it it compounds the issue. You know like your runtimes drop and not just tightness, but insulation. I said tight. I should have said insulation in this case actually being tight, helps with with humidity levels.

But when you insulate the thing with r400 and now you've got no heat load. The things don't run so dehumidification real simple, because in this market it's huge dehumidification is a function of evaporator temperature and run time full stop. If you want to pull more moisture out with the equipment, at least on the equipment side, then run the system more with a lower evaporator temperature and the easiest way to do that is to put more load in. So if you have a house, that's got a real humidity problem.

Pull all the insulation out of the attic it'll it'll take care of the humidity problem. You took you guys a second. There see you're starting to get it, but it is like. I had a guy one time.

It was like we're having non-stop issues in our master, bedroom, humidity, humidity, immunity, i even added another 12 inches of insulation and it didn't solve the problem. It's like yeah. You just made it worse because you took away run time, but the other part, because the structure and the equipment are not separate from each other, is also infiltration, always look at infiltration, especially from addicts. Do you guys have a lot of unconditioned addicts here? A lot of uh, okay, unconditioned addicts, are the devil in terms of humidity they're terrible.

Why? Because the dew point in attics, you should measure it sometimes take a psychrometer up in the attic and measure the dew point. Absolute moisture in the attic is astronomical. You some cases will have dew points that up near 100 degrees, which means that, just in case you missed it. If there's anything in that attic, that is 100 degrees, it will start to condense right.

So you wonder why ducks start to sweat? Sometimes i wonder why you sweat? Sometimes you get it. Addicts are bad and then what do we do? We say: well, we really want good lighting in this house. So what kind of lighting do we put in the ceiling? Can lights right? Oh, but but the good news is, is that with the can lights are at least sealed right? Of course, that would be ridiculous. We wouldn't we wouldn't put things in our ceilings all over the place that are wide freaking open to the attic.

Would we, of course we do so? Those are the things we look at infiltration to. The attic is the worst so reduce attic infiltration. The way you do that is take the can lights down, put in led cans that are sealed and that will that will help for sure and anything else. That's unsealed to the attic space there you go tongue and groove, yep yeah.

I don't know if you recent city with general garcia, he's in the miami market and does this type of consulting, and i said, what's the number one problem in our market with humidity, and he just was like that tongue and groove. That's it tongue and groove that easy and guess what i have in my ceiling in my house that i built five years ago tongue and groove and guess what happens up in the peak of the ceiling uh i get a little friendly black paint that shows up Up there, every once in a while that i have to wipe down with bleach. It's weird, don't tell my wife, you'll, be fine, you'll, be fine. It's fine! The kids are fine.

I know they're all coughing, it's fine. It's probably just covid again back to back to pre-planning, looking at loads. Looking at designs having an understanding of your market is key tribal knowledge of your market is important, but you know know some models again when i said know some models that could mean additionally, no know how to use the models of manual j manual s manual d. For a lot of people will be like.

I don't have time for that stuff. I don't have i'm so busy, i'm not saying if you're a you know, one or two man show and you've never done manual j manual gmail, asking your whole life that i expect you to right now start doing it. You can hire somebody to do that. For you, there are people, consultants, you can get on the phone with and send them some pictures and they will walk through how to do it.

And then you don't have to do it yourself and i'm fine with that. In fact, if you're an old dog - and you know you're not going to learn new tricks, then that's probably what you should do at this point and i'm not saying that, because a lot of people be like well you're taking the skill out of the trade people Should know this stuff, i'm like i get it, but also be pragmatic, do things that people are actually going to do and if that's, where you're at then do that, but know that you do need to have a process for doing because again, you know the last Time i did a manual j, i don't know either because it was so long ago. Like i don't i don't i'm not just sitting at home a lot of people. Imagine because they hear me talk about this stuff on the podcast that i just sit at home and do all of the stuff that i talk about all the time i have done all of it, but that doesn't mean that that's still part of the practice in My business meaning the business, does it somebody does it not me all right? Let's talk about some design considerations, and this is just coming down to think about the envelope think about this.

Can you know what we just talked about tongue and groove um? Is there some sort of calculation factor in manual j that compensates for the fact that some houses use open cans and some use closed cans? This is what i'm talking about. A model is only as good as the inputs and even the best inputs are going to be flawed at times, they're not going to make up for just bad design or an envelope that you can't control and you are not going to control the humidity in a Bad envelope, not like a so-so envelope, we deal with that every day, but like a bad one like where there's gaping holes into the structure which happens like there are cases where, like you know, fireplaces all kinds of weird stuff that you'll get where you'll have just Openings into the space, if you work on 80, is 80 open combustion furnaces, pretty common in this market, just open, open front combustion. You want to talk about a ridiculous design like we've been doing that for generations, but in a humid climate. Where are you getting your combustion air from somewhere? Hopefully, otherwise people are dying, left and right or having headaches that they aren't diagnosed, but you get it from somewhere and often it's probably the attic in our market it is, they put a little grill right up into the attic right there by the appliance and all Summer long, it's just sharing air between where the furnace is in a lot of cases, it's inside the conditioned space.

Now again, if it's a garage, maybe it's not as bad. It depends on the situation like that's, not a great design like i don't know why we haven't gone to, even if we use 80, because in the modern markets, like my market, we don't care about the efficiency. We don't have a long enough winter, but we can still have sealed combustion 80, where it's bringing in the combustion air from the outside. I don't know why we don't do that, but that's neither here nor there, but you got to think about that stuff.

There's not there's no compensating factor in manual j for combustion air going into an attic you just hey if a 12 by 12 is good. The 24 by 18 is even better right. Just give it more. We want to be safe.

You get the point bath fans, kitchen, exhaust, dryer vents. Have you ever been into an attic again, i'm assuming we have. You probably have more basements than attics here. Do you have both more basements very few basements? Okay? So it's very much lake florida.

Then i feel right at home here: crawl spaces, not like a northern basement, because it could be a basement, but a patient, that's tied to a crosstalk side yeah if you're taking dryer vents and you're venting them somewhere other than outside. I don't care where up at the roof peak whatever i didn't, i didn't used to know any better. I said: hey the code allowed it or whatever we do all kinds of weird stuff. Bath fan same thing, just vent it wherever you can and there's so much moisture, that's contained in both of those air streams.

We want to get it out of the house and as far away from the house as we possibly can right right. That's the exactly right place the right place, to put it, take that dryer vent and just point it right on the condenser that will help it in heating season to heat the house better. You put a warm jacket around the outdoor coil. That way, it keeps it warm.

This is obvious, always one guy, always one smart alec, my goodness things like thinking about where the where the dryer vent is to keep the condenser away from it, shrubs all that kind of stuff a lot of times. We don't plan for this stuff, how many times, if you've done installs, you show up. If you work for a company that has a separate sales team, do you show up, and it's like yeah, that condenser's sitting there, because it's this big and this one i have is the size of a sherman tank and you're expecting me to put it there like That doesn't work. You know that's part of the pre-planning and planning process.

Here's an interesting one watch out for radiant barriers in the attic. Why does it say that watch out for radiant barriers in the attic? Anybody have radiant barriers here they put that it looks like tin, foil up against the roof deck or they use the plywood that has the silver coating on it. I used to think those things were great and well in florida. We have them all the time we have this place, called the villages y'all ever heard about the villages before it's florida's.

Oh okay, i got to be careful about the stories i tell next. He does all right yeah. He doesn't have a colored loofah on his antenna. Does he he'd okay, good yeah, all right? Well, that doesn't mean anything there.

Apparently. So i'm just saying: if you go to the villages just watch out for people with loofahs on their antennas, i'm not going to tell you what it means. You can look it up later if you want, hopefully with your phone in private mode anyway, so in the villages, they really love, radiant barriers and, and so what a radiant barrier does is it prevents radiant heat transfer between the roof, decking and the attic space? Okay. What does that mean? Radiant heat transfer? That's the easiest way to explain it, because this is something people don't don't realize and at first i'm going to give you my favorite example of this that we don't think about.

We think of radiant heating. When you walk out in the sun, the sun beats down on you. It heats you up right, that's an obvious one, and can the sun heat you up hotter than the outdoor temperature? Yes, it absolutely. Can we know that right you take something you set it out in the sun, it can get much hotter than the air temperature and that's radiant heat.

It's electromagnetic energy transferred from the sun. We get that we get that when we sit in front of a campfire. We can put our faces our hands like this blocking the light from our face and our face isn't as hot right. We understand that, but have you ever thought about if you're in, like a northern climate and there's a really cold wall and you're exposed to that cold wall that you feel chilly, even if it's warm, even if the air is warm inside the space? That's also radiant heat but you're, the radiant heat conducting not conducting radiating heat to the cold wall, that's called radiant cooling or actually your radiant heating, the wall anytime, there's a temperature difference and there's line of sight, electromagnetically, which is another way of saying visually.

But there's this whole spectrum of light that we don't see with our eyes call it light call it electromagnetic waves whatever, but if that, if that wall back there in the back of the room, is hot earth in my body, then i am going to pick up. Radiant heat from that wall, and if that wall is colder than my body, then i'm going to give up radiant heat to that wall. Even if the air in between doesn't change temperature, does that make sense? Did everybody get that that's how that works? It's not just a light thing: it's not just like standing in the sun thing, but here's an interesting thing about radiant heat i could take a piece of i could take a hot skillet, for example, and i could take a piece of tin, foil and lay it Over the hot skillet and put my hand on the piece of tin, foil air gap in between, i just lay it over put my hand on the piece of tin, foil and, if my hand would stay cool for a while. Eventually, it might heat up a little bit because there is some radiant heat absorption, but that tin foil is very good at not picking up that radiant heat.

Why? Because it reflects it back, that's what it does it takes that electromagnetic energy rather than absorbing it just sends it back where it came from right, make sense y'all with me here so far. Okay, what happens if i take that tinfoil and i push my hand down on it onto the hot skillet? Now it's conduction and that's a different story and you will feel it right. So here's the first thing you can't squeeze a radiant barrier. If you squeeze a radiant barrier, it no longer is a radiant barrier, it is now a conductive barrier and it helped absolutely nothing probably made it worse.

So this is just it says. No. This is pertinent to nothing that i'm talking about really other than just the topic of introducing this concept to you. You can't squeeze a radiant barrier right.

So what do they do? They take this attic decking and they let's say that it's just got a a facing of silver on the back side of it. The plywood comes with the radiant barrier on it right. It's relying on the fact that there's an air gap on the other side. So what is it doing? It's preventing the rejection and absorption of heat from the mass, the material, the stuff in the attic and the roof deck.

So what does that result in? Well, it results in the roof deck itself, getting hotter the roof deck itself. Now i can't reject into the attic, so it's going to be hotter. The roofing material is going to be higher temperature, which means that radiant barriers aren't great for your roof itself, because now your roof stays hotter right. That does happen.

Is that a big deal, probably not right, but it's true, but what does it do to the mean or average temperature of the surfaces in your attic? What happens to them? They drop right. That's good cooler attic equals hooray, but here's the trick. What does it do to the temperature of your ductwork that's running through the attic? It also lowers that uh-oh, because what can tend to happen in that unconditioned air mass? Well, it's stagnant. It's still hot as blazes up there, maybe not as hot, because it's not receiving the radiant heat, but it's still hot, really hot.

The dew point is still really high. It's still really humid. But what did you do to all the surface temperatures in your attic? What did you just do to all of them? You lowered them if they were close to dew point before and now you put a radiant barrier in guess what happens? You create a rain forest in your attic, which is fun for all the little things that want to live up there. If you've had a case where it's like, i don't know what just happened, but this ductwork started sweating.

All the vents started. Sweating everything started sweating. All of a sudden watch out for radiant barriers watch out for uncontrolled addicts all together, because one nice thing about ventilation at the very minimum, even though the attic is still hot. The dew point in the attic tends to stay closer to the outdoor dew point, which that sounds bad, but it's really good, because addicts can get really bad ventilating addicts for humidity, pretty good, so long as you're not causing an air exchange to the space case.

In point make sure that your attic, if it's unconditioned, is sealed as well as possible to the space full stop. If you want to go to really solve the problem, then completely seal the attic and put a dehumidifier up there. So cfm is what what does it stand for cubic feet per minute, so that is a cubic foot. A box of air per minute moving every cfm into a house, has to come back out of the house every time now with a typical air conditioning system heating system, it's just recycled right, you put one in you, take one out all the time, but if anything Disrupts that balance anytime, a cfm of air, goes outside of the house.

What happens? Another cfm comes into the house, it just does you're not going to keep it from happening. It just does. When you take a, i don't know. Whole house fan you take a bath fan, you take a you know this customer really got.

They got a new range hood that they're really proud of, even though they never cook they just like to run it in a 1200 cfm in a second well, if you're running 1200 cfm on your range hood you're, sucking in 1200 cfm from the outside, and if You have gaps and cracks to your attic, you're, probably bringing it in from the attic if, in this case, you're venting out of the attic which attic ventilators like oh solar, ventilators, that's going to solve the problem. You want to make it sealed to the house, and you want to make it really easy for air to come in from the outside. Otherwise you're going to depressurize the attic and it's going to suck air in from the house into the attic. And then the house is going to suck air in from underneath the doors and around the windows and everywhere else, and that air outside is humid right.

So it causes a problem. It's all pretty simple: it really isn't that complicated and you don't need to be that great at math as a technician to catch on to these problems. But it's just not what you think we always are trying to solve the problem with the same solution, and i learned this the hard way so um anybody here watch golf any golfers here you seem like a group of golfers to me. You just look like golfers.

You know there's this: guy named marco mira he's an ex-masters champion. It was drained like the tiger woods area era. He lived in the same subdivision as tiger woods. I used to work on those houses and we installed all these new systems and the vents just kept getting stuff growing on them everywhere like and i was panicking.

So what was i doing? I was, i was like taking insulation and just like piling it up over the vents. Like i didn't know what i was doing, i just was trying all kinds of stuff. Well, eventually, it gets so bad that he's got all this growth on a vent. That's right! Over top of his master bed just mold everywhere, i just said it dm ward right, a moisture problem right over top of his master bed, and i thought i had fixed the problem - i probably didn't.

But what do i? What is my job now to do? It's to make it stop, looking like that, what are you supposed to do when somebody has like a california, king water bed in the middle of the room and the vents right over the right over the center of it? What are you supposed to do? I i ask you, because i didn't know you know i was 19 20 years old, so i set up a ladder on the guy's freaking bed like this. Oh my god, with with bleach doing this and just thinking this whole time like because i watch golf. I like golf like this guy's one of my heroes, he's a nice guy, i'm in his house, i'm just imagining this guy walking in seeing me do this, and that was the impetus for me to figure out how this stuff works so that i never have to Do this again and i'm not joking, that's actually how that happened, more design discussions to have with the customer. This is sort of my ultimate um ac installation, and it has some stuff in here.

That's you know it was maybe a little more controversial, more controversial parts. Would be the apco x here in the supply duct and the uv lights above and below the evaporator coil, i'm not a huge fan of those technologies. In general, i've been pretty um outspoken about that, but there's a place for them a uv, i'm fine with as long as it's done properly. Pcos be careful, you know with them.

It's not something that we just throw in every house. That's my opinion, but the other stuff here is worth noting, and this works very well in our environment, and these are things that i wish we would have more conversations with our customers about, because ventilating dehumidification, when done properly with good equipment, is a really nice technology. It really works great because we know, especially in the covet era, that ventilation air outdoor air is great for our health. It really is dilution.

Air is great, and it's not just great, because it smells fresh, it's great, because it actually dilutes the viral concentration within a structure, because it's not just a matter of having one little virus just land in your nasal passage. It's a matter of the concentration of it, and does anybody here think that we're never going to deal with a viral pandemic again ever ever ever ever again? Now anybody think that no we're going to like this is going to happen and so having some solutions that we can provide is going to be a really good thing. So ventilation air is part of this, but you can see we're bringing in ventilation air here we're using an ecm blower box that we can independently control the ventilation. Here.

This is a mac daddy system. Here it's going into a ventilating dehumidifier and then it's going into the supply air. Why do we put a ventilating dehumidifier or a dehumidifier at all? Why do we dump it into the supplier and not the return? Anybody know why? Wouldn't you dump the dried air from the outside into the return rather than the supply. The answer is well.

I like that answer. That's actually really! That's a good! That's a that's a good way of saying that yeah he said it's where the driest air is. Now. Here's a tricky thing: has anybody ever measured the relative humidity in the supply duct? I just want to be clear about what we mean when we say dry.

It's it's very high relative humidity. If you've never done it, do it sometime, it's going to measure somewhere between 90 and 98 generally. How on earth could the air in the supply duct be 90 to 98 relative humidity, when it just went over the evaporator coil? You saw the water come out and drain out the drain, and in this return it was 50 or 55 or 60 percent. Hopefully, less than that, because it's relative to temperature right exactly when you cool the air, you shrink the size of the sponge right shrink the size of the sponge.

It can hold less water, it's 100 full because you squeeze it down. When it gets back into the space, then it expands back and now the humidity percentage drops way down. But when it's in the duct it's high relative humidity, but to his point it's very dry. In terms of absolute moisture right and that's why cold air is dry air in terms of absolute terms, you could have cold air - that's 95 relative humidity, but it's still going to be low, moisture compared to a hot summer day anywhere, because cold air can't hold much Moisture it could be 100 full and still not have that much moisture in it compared to hot air.

That's why attic dew points tend to get so high, because hotter air can be more full of moisture, doesn't mean it is, but it has much more capacity. It's a much bigger bucket can hold much more water all right. So why do we put dehumidifiers into the supplier? This is just something you do, i'm not giving you the option. I am by dick royal decree stating that you do not put dehumidifier air into a return and here's why that air conditioner is a very good dehumidifier.

It is very good at it, but what's the problem with it, why isn't an air conditioner? Because sales people have said this for a long time. Well, hey! Look if you've got a good air conditioner and you size it properly. You never need a dehumidifier. Never what's the problem with that statement, what's the liability of an air conditioning system? Well, it's going to break eventually, that's one thing: what's that conditions and partial load conditions, that's exactly it because if you design that system you're designing it so that it can cool the structure during the hottest day, you are designing it that way.

So when you're in part load conditions, it's going to struggle now they say yeah, but that's true of old systems, but what, if it's an inverter driven system or what? If it's a multi-stage system? Well that solves that problem. Doesn't it haha? I got you what's the problem with that. The problem is that regardless, it's still cooling the space, so no matter what you do, it's still cooling the space and unless you need cooling, it ain't gon na dehumidify and at times during certain seasons. During certain points, you're gon na have some of your worst moisture conditions in the mornings in the evenings.

Sometimes when you really don't need it to run at all, so a dehumidifier. If you want it to maximize its optimize its capabilities, you don't want to dump a bunch of dry air in the return, because what that, what's that going to do when the system's running, it's going to derate its ability to remove moisture? Because you just dried out the air going into the evaporator coil, so now the air conditioner is not going to dehumidify as well. The next thing is: is that now you're going to recool that air, if it's running one of the actually big advantages of a dehumidifier, is that it does actually add some heat that heat increases the load which makes this equipment run more so now it's a double Whammy, it's increasing load, it's helping the equipment run more and it's dehumidifying. Now people say yeah, but that increases your power bill yep.

Any other questions. You know what else increases your power bill running your air conditioner at all. So if you want to decrease your power bill, throw your air conditioner in the dumpster and never run it well. I can't do that exactly and if you're having a moisture problem in your structure because of your climate, because the way you're living in your home, then you need to have a dehumidifier.

Now. What are the houses that are the greatest risk of issues? Tight houses can be can be, there's an advantage to type 2, though the advantage to tight is if you really are tight to the attic, that's good, because that reduces infiltration. Here's my list of of bad number, one bad structure so bad envelope. Now, when we said tight by that, if we meant new, then i would agree because newer homes do tend to have more trouble, we'll talk about why that is but bad envelopes that are leaky to the attic or crawl space or outside those do cause more problems.

But if that's the case fix that problem or get somebody else to fix that problem before you go trying to solve it blower doors. This is where things like blow door, testing and envelope. Testing come in really handy, not on every house, but in cases where there's potentially an issue. So that's one two would be installation issues with the equipment and that would include things such as leaky ductwork.

That would include things such as the equipment not set up properly. That would include such things as the system not charged properly. Anything that makes the equipment not work right is definitely on the list of dehumidification, but here's, the third one and the one i'm getting at it's customer practices the houses that have the worst issues with growth. In the houses are houses where the people keep the temperature really low.

You know why your grandma and grandpa didn't have these issues because they weren't entitled monsters unless they live in the villages. I did not say that no. The point is, is that there was an entire generation of people who, just they saw air conditioning as a luxury. It was a luxury heating, wasn't a luxury because you die.

I had a lady one time in the middle of the night, who called me 3. Am something like that this is before i had my own business and i had the on-call phone. You remember when you used to have that it was, it was actual phone and they would leave a message and you'd have to call back the message and you have to write it down and on the message she said. I have a parrot, it's a very expensive parrot and it cannot handle these temperatures.

You need to come immediately and i thought to myself. Lady, do you know where parrots come from because it is not wisconsin, but that is i mean there is just just a general sense of entitlement that surrounds air conditioning and that's, okay, i'm not making i'm not doing a social commentary here. Yes, i am. I am a little bit, but it's just a reality.

Right people view air conditioning as their life's blood and if they want to keep it at 67 degrees inside their home, then by golly. That is their right to do right. That's how they feel, and i agree it absolutely is, and it's also their right to lick the mold off their walls and duct work that grows when they do it. That's just how i feel about it so and why does that happen? Why does mold growth result from people setting their temperatures lower in the space lower dew point right, lower dew point, lower dew point on the outside of your ducts, lower dew point on um everything on the walls and the inside you'll see cases that are so bad.

Where you'll actually begin to get uh mold on the inside of walls that aren't even related to the air conditioning, just because maybe there's a vent over here, that's blowing, something like that and you'll start to get mold on the wall. There. Here's another interesting one. Do you ever have a furnaces or air handling units that are installed in closets and unconditioned spaces like garages or anything like that? Do you ever have that? Have you ever pulled out a unit pulled it out and behind the unit? Is this big black spot right behind where the evaporator coil is, if it's a furnace it'll be the top portion here? If it's a, if it's a fan, coil be the whole thing: it's because the proximity of that wall to that unit and the box is colder.

Even if the unity itself wasn't sweating that bad, what it does is, it translates radiant heat from that box to the wall. Radiant cooling, so it's radiant, cooling, the wall by the by the unit, and it causes that wall to hit dew point similar things like that. Can happen and are much more prone to happen in houses where they have the setpoint lower, because if you have a 20 degree delta t and it's 75 degrees inside, what's the supply air temperature 55. if they keep it 68 inside the house, what's the supplier temperature 48, that means ducks everything is going to be more prone to sweat in markets where the humidity isn't high have at it, set it as low as you want - and i get in this argument all the time, because i'll say these things and somebody in arizona or Utah will pipe up and say that's ridiculous.

We give all of our customers, you know four or five ton units in order to cool a thousand square foot house, and we do it all the time and it works fine. It's like yeah have at it. If you don't have issues with moisture, then do what you want, but in our market it's definitely something to think about. Moisture issues with venetics is also really big.

So this is another sort of entitlement dichotomy. You'll have people who buy really high-end units so they buy a carrier infinity or they buy. Whatever the you know, the linux signature, dave's little signature series or whatever rheem is called nowadays buy this highest end unit and they put it in and they buy it because it's what energy efficient right, it dehumidifies really well, and so what do they do? In response to that, with their set point, they say well before i kept it set on 77 and now because i have this sufficient system, i'm going to send it to 69, and i think that's okay to do, because i'm paying so much less for this. That does happen.

There are people whose behaviors change after they purchase a new unit and what's uh, what's the sales person's favorite line to say when they're selling a unit somebody we're going to get it so cold in here you can hang meat in here. Why do we say that who wants to do that? That's a ridiculous idea. I don't want people hanging meat in their house. That's that can't be healthy.

That's not good! For your children! Don't hang meat in your house. New policy salesmen are not allowed to sell meat. Coolers to our customers anymore, and so you do that and that's so. Customers will come away with the idea that somehow they can change their behavior and a lot of times.

It is behavioral change that results in issues like this. With with moisture, i mean we know that this happened when it was, it was anybody around i'm asking this tongue-in-cheek. Was anybody around uh during the the transition from mercury thermostats to digital thermostats yeah? I mean quite a few of us were, and you would put the digital thermostat in digital thermostat and the customer would be unhappy. And why would they be unhappy? Because i used to set my thermostat to 83 and i was comfortable and now i have to set it to 73 in order to be comfortable right, because the inaccuracy just so happened to be to a degree where they felt really good about their set point.

But it didn't represent reality, and this is kind of a similar sort of thing that occurs with high-end equipment, especially when we sell it improperly, and this is where, when you have really, this is something i'm just going to encourage you. If any of you work in really high-end homes, especially if you're installing it right before a new client comes in or they're making significant changes to their home, maybe they just bought the house and now they're making all these changes, or you know that they have some Objectives that aren't realistic for your market don't just deal with the equipment, because if you put that equipment in they're going to blame you for everything else, that's wrong with that house. They're going to we've walked away from so many jobs since learning this that it's not a joke, because we've realized that there's a group of people that think that money buys them irresponsibility and habits, and it does not money. Buys you a really good air conditioner.