Hey thanks for watching this video. This is one class from the 2022 hvacr symposium in claremont florida. We have the symposium every year and so to find out more information, kind of upcoming go to hvacrschool.com symposium big thanks to our sponsors. For this event, which was accutools and trutech tools, they're the two title sponsors that made the event possible in this class, steve rogers and chris hughes from the energy conservatory talk about a basket case house a house.

That's got all kinds of issues how to diagnose it and how to deal with it. So thanks a lot for being here uh, my name is bill. Graber, i'm with the energy conservatory and i'm steve rogers, also with the energy conservatory we're going to talk about a basket case house today. You guys, i'm sure, have never dealt with a problem house right, and so this is built on a real experience of a technician.

Uh in the miami area, who was dealing with a problem - and he is really elevating - you know how he analyzes homes and we're going to share what did he learn? How did he learn this, and how did he do it? You know, and how is he sort of refining the process he uses when he's got a problem situation where the homeowner's conv, you know, is having a real issue and convinced yeah? It's the it's, the hvac guys problem and he is figuring out a process to say. Well, maybe it's my problem if it is i'll fix it, but i'm also going to make sure that if it's not my problem and it's your house, it's not the t system, there's something else, causing your comfort issues. I'm gon na develop a quick way to diagnose that and be able to say not my issue. It's something else and i can help you still solve the problem, but it's not my issue.

So just a quick introduction, i'm the marketing guy, i'm down here, uh bill. Graber my my real name used to be bruce wayne, but i changed it and and this guy's steve rogers, if you didn't get that joke, that's captain america's name. So all right, i didn't want to be batman. So i changed my name to bill graber, okay and we're tec, the energy conservatory.

We we make these corridors and things that check houses, but where we also make like the uh true flow grid, uh more aimed at getting airflow right right, and so the two together are here to say: hey: how do we make houses better, and this has been A mission for over 40 years by the founder, okay, and so this is really the premise of this presentation, which is hey. I got a problem house and what's causing the issue, is it this thing or is it this thing and how many people in here have been in a situation where you've got what you call a problem house, just one that just keeps coming back and you can't Get rid of it yeah, so we want to be clear. We don't have the answer for that. There isn't one answer for that: what we're trying to share and do is start a discussion amongst frankly, a really if you're, here, you're here, because you are elevating your game and we want to learn from you too part of the reason why we're here is to Spend time with guys like you is how things like digital true flow happens right, so we want to solve real problems, help you guys get paid to do better work.

We don't get paid. If you guys don't get paid, you guys don't buy our gear unless you're doing well. Okay! So we're not here to be the experts on all of this we're here to just let's get a conversation going and let's share what genre has done, because that guy's doing some great work, okay and so yeah. The idea is sometimes new approaches can make solving problems easier, i'll, just jump right in, but the last thing i want to talk about before i hand it off to steve he's going to step through kind of the science of how did they do this analysis? Is this is just a concept because sometimes i think people hear and there's kind of this you know discussion going on in the community.

Oh careful of home performance and building diagnostics. That's a great way to go out of business if you're a contractor, because, frankly, you start looking at a lot of data, but you don't get paid the concept that we have is but but hold on uh. If you ever work and the homeowner asks you for something that you're not an expert in, do you have a guy for that, if you're not an insulator but they're, looking for an insulator, do you have a guy for that, for geothermal, for whatever is not in Your lane, do you say i don't do that, but i i know a guy. I could point you to that's.

Maybe the way to think about home performance or building performance. You don't need to buy a blower door, but maybe it will be a good idea to know someone who has one just in case you get into a situation where you have a problem home. You can't get rid of and you you test out your system, and you say i think it's your house, i could you know you could bring this guy in and it costs about this much if you don't want to own it yourself right. This is a way to get started.

That's all i'm saying that's kind of what generate garcia's business is in miami. Is he does a lot of work for other hvac contractors who can't figure out the problem homes like? Oh, i got to call jenny on this one. It's it's a it's a problem house yeah and that way they get to move on, because it's not their system, they've done the work they need to do and then they they hand it off. If, if you look at this and go man, i don't really know if i want to do this challenge yourself to say, but who do? I know that i could hand off some of my problem houses to because i've checked out my system and it's not my system, and i want the homeowner to not think i'm not doing my job, so i want to hand it off.

I need to find somebody like that in my area that i can hand it off to so. This is how it starts, and then i'm gon na, let steve take you through it, but the complaint was a common one in miami hey, it's just too warm everywhere. In the house, this house is just not comfortable when it gets hot, it's running all the time and it's not comfortable, and so it's not maintaining a set point. It's going to 80.

When i have my set point at 72, i've got very high relative humidity indoors and i can't figure out. What's going on, okay and so steve's, going to step you through some of the steps to diagnose that i'm going to walk you through some steps here and bill mentioned, we want to start a conversation. Part of the conversation we want to have is you know what, as you look at these different things, that we can do we'll talk about each one of these we're not going to mandate or suggest that this is the right order. They have to happen depending on what you find you might be going in a different order, and that's part of the conversation we want to have, but we want to talk about, is what does each one of these diagnostics tell you about a problem house and what Are the next steps if you find out that this is okay, or this is not okay, so the first one you know you might just do a visual inspection? Look for you know.

Are there like disconnected duct work in the attic? Do you have uh? You know a system that you have a line. That's freezing just visual inspections can tell you a lot okay and we'll yeah we'll talk through each one of these, so the visual inspection. You know if you crawl into an attic, and you see this. Okay, that's a reason: a system would not be keeping up right if you see a big gap in the ductwork you're losing tons of the of the air out that leak and that's going to cause the system to not keep up.

Okay in this house, uh, the technician did go in the attic and didn't see any obvious duct leaks. So we checked that off and say: okay. Well, we did that uh. Visual inspection did not reveal any any major duct leaks.

Next thing you want to do is be checking the airflow if you've got a system, that's way low on airflow. That means you're way low on capacity too. So in this case that the technician did check the airflow, with the measure quick and with the true flow grid and verify that the air flow is okay, it's within the range that's acceptable. It's not a reason that you would be slipping.

Eight degrees on a desi on a day: that's not even uh a design day. Look at the design review. Okay. So if the system's not keeping up, is it big enough for the house only way to know that is to do a load calc? You know? Maybe you can look at run time, but if it's not keeping up it's going to be 100, so load calc is is a next step, and in this case the technician did the load calc, and what i've got here on this bar chart is the uh the Equipment capacity here the blue is the sensible capacity and the orange here is the latent capacity.

So, as you do your sizing, if you're following the manual s process, you know that you've got to have enough capacity to cover the sensible load and the latent load or the cooling and the dehumidification okay. So the technician in this case did the load calc and found out that this is what the house needs. The house needs uh this much latent and this much sensible, so the system's covering 114 a little bit more than necessary of the of the sensible load and just slightly more than the need you need on the latent load. So is this system sized correctly and the answer is yes? Okay, so it's not that the system's, not big enough for the house load calc was done.

Load calc says we're okay. So, what's going on the next thing to check, as i mentioned before, was airflow, and you know i talked about that out of order, but the airflow was also checked and the airflow was normal. Okay, the airflow is okay. Okay, the next thing that the technician wanted to do here is look at house pressurization have any of you ever done a house pressurization test.

You know what that is. Okay, we've got a couple of us have done that house. Pressurization test is, is actually turning on the hvac system and measuring the house pressure with it on compared to with it off, and does it change if the hvac system is taking all of its air from inside and returning it back to inside then turning the hvac System on should not change the pressure in the house if it changes the pressure in the house, then that means that air is either leaving the duct system to outside or it's getting sucked in from outside, depending on whether you go positive or negative. So let me explain what that test is okay, the test is done by you.

Just have the manometer uh inside the the main living space and you run the uh, the tube on the negative side outside so you're measuring the house pressure on your positive with respect to outside, and you make take that measurement with this system turned off and you'll Get a number um and then you turn the hvc system on. Let it get up to full speed and measure it again and did it change if your ductwork is all sealed and your all the air that leaves the outside is coming back to inside the pressure shouldn't change, okay, but in this case here's what the technician found With the system off, he measured 0.8 pascals tiny pressure. 0.0032 inches of water is how much that is in in inches of water and then with the hvac system on it jumped from plus 0.8 to minus 1.2. So the difference the amount that it changed was 2 pascals or 0.008 inches of water.

Okay, zero 0.008. Does that matter? That's a tiny pressure, we're going to talk about why that matters and what he found? Okay. So this is what i mean by house depressurization test. This is different from a blower door, you're not using the blower to pressurize the house you're, actually using the hvac equipment to see.

If the house pressure changes the the system off pressure it, it shouldn't necessarily be zero. That's just because of the stack effect. It's the temperature difference between indoors and outdoors will create a pressure. That's not zero important to recognize when we start talking about wind that on a really windy day, you can't really do this test, because the wind might be fluctuating by 10 pascals.

Are you going to see a difference of two pascals, probably not okay, so you kind of have to wait for a calm day to do this test, so this is what's measured and uh generally, how long did it take you to do this test? Two minutes. You got two minutes: okay, now we're going to talk about the importance of of this test and where those two minutes led the technician. Okay, so house pressurization house is depressurizing by two pascals when the hvc system is on that's a problem. How big of a problem? We need more information to say, but it's a problem: okay! So here's what we've measured um! If the house goes minus two, when the system runs, here's what's happening.

The hvac system is pushing 1400 cfm. Okay up through the attic. This system had no return ducts in the attic. The return is just a filter on the bottom of the cabinet in the living space.

So all the all the hvac ductwork is on the supply side. That's in the attic, so 1400 cfm leaves. The house goes into the attic and some amount of it leaks out, and some amount of it comes back in okay, and we know that because some of the air is not coming back in this number of air coming back into the house is less than 1400 Because some of it's leaking out and then you know falling out the soffit vents or whatever um, and so what that means is that the house is minus two and it has to make up the difference between how much is coming in and how much is going Out and that difference will always get made up by sucking air through all the cracks in the house. Okay, how do we know that the air there's air coming in? Could it be the case that the air is not coming in exactly that's exactly right? We know that there's the the difference is being made up, because the house did not collapse: okay, okay, so so far uh we know there's supply duct leakage but, like i said, the technician went in the attic and did not see any major um problems in the Ducts and we're leaking quite a bit we'll talk through how you find out how much you're leaking, but we know there's a supply leak.

We just don't know where it is. Okay, so uh next step would be room pressurization, that's a very good diagnostic, but in this case we're not talking about certain rooms being uncomfortable, so that test is really not necessary. If the problem is the system's not keeping up, even with all the doors open in in the living space, we know there's a problem minus two pascals of depressurization but um. We don't know how much so to know how much leakage you have.

The next step has to be a blower door, or a duct blaster test can actually help you find out how many cfm are leaking out of the um out of the system, and in this case the technician did a blower door test and he measured 3230 cfm, Which is 9.4 ach? 50.? Okay, that's not a very tight house, that's pretty leaky, but it's also pretty typical of this age house in miami okay. So not a good number um, but not really the reason that the how the system is not keeping up, especially because the the technician in this case he put this leakage into the manual j calculation and so the manual j, is accounting for this much. This much leakage under normal conditions, okay, but what manual j is not accounting for is that the house is depressurized by the system. Okay manual j can't account for that manually.

J doesn't assume a certain leakiness of of ducts, okay, so here's what we've got. We've got uh an envelope test 9.4 ach 50 32 30 cfm 50, and this can now be used to estimate the duct leakage. If we have a blower door number - and we know the system was depressurized by two pascals - we can actually use this simulation tool that the energy conservatory makes called c-stack and we can put those numbers into c-stack um and we can estimate how much leakage it takes For a house of a known, leakiness go ahead bill. We're going to do this.

Another option to quantify the duct leakage is to use a duct, blaster and measure right, but in this case generate had a blower door available easy and he did it because he wanted it for his manual j2. So you're going to see a way to say. Oh, if i have a blower door - and i did that depressurization test - i can use this free tool and still kind of back calculate in the duct leakage from the blower door. This doesn't this, isn't the only way to do it, but it's sort of a back door way to say i don't need a duck blaster and a blower door, necessarily yeah, and actually, in this case i would say.

Maybe this is the front door approach, because if a duck blaster test won't tell you how much it's leaking in normal operation and that's important here, um okay. So this is what manual j assumes. If you put in that, the house is leaking 3230 cfm 50 and it's a two-story house on a day so that what's important here um is the difference between inside temperature and outside temperature, and in this case we've set it. So it's 20 degrees warmer outside.

So this is actually the same as if it's 75 inside and 95 outside that's a 20 degree difference. That's what we're simulating here and this simulation tool will tell us okay. What we expect to see, then, is we expect to see 102 cfm of air leaking in the top floor approximately and the same 102 cfm leaking out the bottom floor. It also tells us that at the the bottom floor, we should expect the pressure to be about plus one pascal because of the temperature difference and about minus one.

If we were to measure way up at the at the ceiling of the top floor and that's pretty close to what the technician measured, you know the simulation tells us. You should be measuring one technician: measured: um, 0.8. Okay, that's just from the stack effect! That's how much we we should have that's how much we've got so. This is what manual j assumes manual.

J is assuming there's 102 cfm of natural leakage. This number's smaller much smaller than the blower door number, because the blower door number is done at 50 pascals. This is how much leakage you have because of you know: minus or plus 1 and minus one, pascal, okay, so manual j assumed there's 102 cfm of leakage, but the real case. If we change this um, this fan flow and say: okay, this fan flow can simulate what happens if you have duct leakage from the supply.

That's blowing out! That's going to do the same thing to the house as if you had an exhaust fan blowing out a certain amount of air. So if we know that that pressure changed from by two pascals in this case we're going from one to minus one, that's a two. Pascal change um. In order to get there, we have to change this exhaust.

There has to be 384 cfm, exhausting out the exhaust fan to cause it to depressurize by two pascals. So that means manual. J was assuming 102 cfm of leakage in and out and there's actually 384. Okay.

Is that a big deal? Okay? Let's talk about what that does to the load calculation, we're going to do that next, okay, so 384 cfm is what's really leaking. 102 is what we assumed in the manual j, even putting the correct blower door number, and this is what we assumed, because manual j doesn't know that your supply duct is leaking out the attic. Now, let's look at so there there's an additional. You know we assumed 102.

We actually are leaking 384, so the difference is 282 right. So that's how much extra leakage that the manual jcalc is not accounting for let's talk about what that extra 282 is doing to us in the load calc. Okay, so we talked about this diagram before 1400. Cfm goes out now.

We know because we have a blower door and we have the depressurization number. We can say: there's 384 cfm leaking out, so that means there's 1016 coming back in the house and that's what causes? The two pascal difference between when the equipment's running and when the equipment's not running okay. So that means that we know there's 384 cfm coming into the house through the leaks, to make up the difference because, as this gentleman pointed out, the walls didn't cave in. So all these leaks add up to 384 coming into the house.

So now we're going to take a closer look at that load, calculation that we showed you to begin with and we're going to correct it. We're going to correct it for what's actually happening. That manual j can't take into account so on. The left here is the equipment capacity, so we're going to keep this on the left.

I put the you know, outdoor unit here, to remind us that this bar is the equipment capacity, and this bar is what the house needs. So this is what the original manual j uh calculation assumed that we had this four ton system and that should be adequate for this house. That's where we started, but let's take a closer look. Now we're going to look at each side separately and what this leakage to outside does to the capacity okay.

So we started here with this four ton system that has latent and sensible capacity, and then we took about a quarter of the air and we blew it outside okay. So what do you have? Okay, you have reduced capacity. You blow a quarter of the air outside. You've only got about three quarters of the capacity that you thought you had very simple right.

If the air didn't come back into the house, it didn't cool anything down and probably cooled the attic down a little bit, but good luck doing that um! Okay, so we don't have a four-ton system anymore. We have a system, that's much closer to a three-ton system because of the air that we lost. Okay. So now, let's look at what's happening on the house.

Not only did we lose a bunch of capacity, the house sucks it sucks hot air in that's what happens when it's depressurized, so we don't have these loads anymore. We actually have these loads. It's the load is increased because we're sucking in more air than we thought. We were so.

This is a double whammy. Not only do you lose capacity out the attic, but you also add load to the house because you're sucking in hot air, yes, so sensible went up, but look what happened to the latent. The layton is crazy. Now it's like more than doubled, yeah, and so does that explain having a humidity problem if you thought you had this much latent to take care of, and you actually have this much that for sure explains a humidity problem because of the extra 284 cfm of extra Infiltration coming in our load is now now we've got a house that should be four ton, but the load's really closer to five.

Okay. So instead of this is what we thought we had. We thought we had the equipment covering over hundred percent of the latent and 114 percent of the sensible. We thought we were good right.

Here's what we really have. We are really only covering 41 of the latent load and 74 of the sensible load. So now we look at this chart doing we've adjusted the calculations for what the conditions we really have does putting a three ton system on a five ton load. Look more like! What's gon na happen that you're gon na slip by eight degrees on a warm afternoon, this now explains what we're seeing that's, what we really have and again manual jay can't account for this generally came to me working with the energy conservatory because he's like well, how Do i even know how much this matters and he gave me the numbers he sent me the data and i did manual calculations and spreadsheets to figure out how much extra load we have? Okay, so we're taking a closer look at the loads here.

So this is the pie, chart that a lot of your load, calc software - will give you. We've got all the different loads. You know windows we've got uh the latent gain internal gains and so forth. The because of the infiltration we, the total load, gets about 30.

Bigger but most of the pieces of the pie, don't really change much. What changes is the infiltration load, which is the yellow at the bottom here, and i've broken it up into the uh. The sensible load in uh in the dark, yellow at the solid yellow and the striped yellow, is the latent load. And what we're seeing here is that this um wedge in the pi now becomes like almost half of the load is infiltration now because of those additional you know, 300 ish cfm, that's coming in okay.

So this explains what we're seeing. This is a closer look at um at what's going on, uh five ton system now we're up to 1750 uh and but the same. We're gon na have the same percentage coming out leaking out and coming in. That's how the the the flow's going to work in the duct is that if 25 was leaking, you can have 25 leaking with a bigger system too.

If you can get there even so now we got 480 cfm leaking to outside and 1270 coming back in. So we had a minus two pascal pressure change before that's going to go up to something like minus 2.7, so we're getting closer to a three pascal depressurization now with the bigger system in now. What does this do to the loads? So we explain what's happening, we're sucking more air in from outside. Now we got 480, almost 500 cfm coming in from outside okay.

So let's look at the loads here. Remember this chart. This is the four ton. This is what we, what we really have with that four ton: that's in there.

We swap it out for a 510. What do you guys think is gon na happen? Gon na cover it there's gon na be humidity issues: yeah, okay, you're, chasing your tail? Okay. So now we got only slightly better before we were covering 41 of the latent load. Now we're covering 46 is that gon na make a big difference.

No, it's still going to be crazy, humid, okay and instead of covering 74 percent of the sensible load now we're covering 83. It's you know. So it's going to be maybe instead of slipping, eight degrees, you're gon na slip, six okay, so putting in the five ton will only help slightly okay because of the leak. So the message here is, you got ta, find the leak and fix the leak um to to improve the situation so bottom line.

Here we want to start a conversation about what these tasks are. What should you be measuring to try to get to the bottom of it and we? I don't think we really know what order is best for these, and it probably depends on the situation and probably depends on what kind of houses you're dealing with okay. But these are some things that you should be measuring and doing to try to get to the bottom of a problem house. So current status of this one is that um generally diagnosed as a supply, duct leakage problem, recommended a solution and an offer was made to the homeowner.

I think generally is working for another hvc contractor kind of out of his hands. So we don't know if the homeowner went for this one or not, but it's it's out there yeah there's a question. Does any of this change? If it's a zone system with two or three different zones, do you have to run the test with all the zones open? You got to run with yeah. If it's a zone system, i think um, you definitely would want to run the test with all the zones.

Um calling for cooling um that kind of tests, your worst case with a zone system. I think you could have a situation where some zones are going to be worse than others. You know you probably have dealt with the bonus room zone problem. Everybody dealt with that problem before okay.

That problem is almost always an infiltration problem. If you do a blow door test on that house. Okay, what you're going to find is that it's probably not too leaky, but all the leakage is into the bonus room. The way that they're built it's horrible um, and so what happens is so your manual jay is going to say it's good.

It's good, but manual j is going to assume that the infiltration load is spread equally through the whole house. When the reality is it's all. In the bonus room, i think the other thing to think about on your question might be: what's the common setting in the zones for the way they're set up, meaning if they're complaining about an issue and - and just you know again, i don't know what condition you're Dealing with, but you could do this test under a lot of different situations and that simple test that generated the house depressurization would tell you when these zones are calling. This is the depressurization when all the zones are calling.

This is the depressurization there's nothing magical about how you have to adjust the system, try to hit the common settings the way they're actually operating that are causing the homeowner to go. I hate this. This is not comfortable, please fix it. Another question: was there a testing interview with the homeowner to figure out what yeah i'm going to repeat it, just so that everyone could hear it? But the question is: what was the situation and how was the interview up front? Was this a real estate transaction or a problem? You know and and uh? I think the answer is.

It was a problem yeah. My understanding is that the uh original hvc contract, who has not generally had replaced a system and uh found out it, wasn't keeping up and had this complaint. So i i think, that's how it went. You could ask generally he'll know the details.

The thing we're trying to highlight here is if you've got duck leakage to outside um. You know you've got like a situation where don't put a tourniquet to stop the bleeding like you've got some major work to do, go, find that leak and fix it or you're. Never really gon na solve the problem. We're almost done.

This is the way this is a slightly different order and and um. You know we're doing this because you'll be able to get these presentation slides later. We don't know the answer, but if you look at this, this is what we believe is closer uh to what genre is doing more often the minute he got a gauge. That said, i can walk into a house and the first thing i do is house depressurization, because i've got a gauge.

Now, that's accurate enough. You can do this with a blower door gauge from us or retrotech. You can do with a dg8 from us at a pretty low cost, but these super accurate gauges. You can walk into the house and within two minutes know do i've got.

Do i have a dominant duct leakage here? Is my house depressurizing when i turn on the hvac system? If i do man that brings me a whole bunch of insight in two minutes: okay, so yep. What's the number that i measure when i say i got ta, do something yeah and that's in the slide up earlier on. It will there's a little guy that says when i turn on the system, how much change am i looking for yeah, but but on a calm day i mean this. Is the other thing that i'll tell you there's no test, that's perfect! On a windy day, this test kind of isn't going to bring you much insight, you're going to just be fluctuating.

So it's not a perfect every single time. It's going to give me the answer. You know, there's a reason why the whole industry doesn't do this one. They haven't had an accurate cost, effective gauge to do it, but two, it's not always available to you.

That's right, referenced outside the short answer is one pascal, that's just kind of a rule of thumb, but the the longer answer is one pascal could still be a problem on a really leaky house. It depends a little bit on how leaky the house is a tighter house. Two pascals might not be a problem. Will it scale with the number of stories uh sort of the leakage you get more leakage from a two story than a one story, um, so yeah? We can make a table for you no, but um, but the the leakage with a one story is not half of a two story: it's like two thirds of a two story, the way that the math works out.

So you know this. We don't want to get too commercial, but the idea is this is what changed for january? You can do all these tests if you, if you just want a really accurate gauge now you can get that for under 600 bucks and that's blower door style pressure measurement right, really super accurate at a price. Where, maybe you go hey, that's a good price. If you want to do the air flow too, these two work together and you add about 600 bucks for this.

These are expensive. That's why up front? We said, don't start here, find somebody that can do these tests for you in your community so that if you really get stuck and you need this, you've got it. But if you're just getting started - and you just want to start to get a feel start up here, because you can get a lot of these tests - house pressurization room pressurizations and that guide you to what should you be looking for and the system air flow and Static pressure. Okay, but like we said you can do this with a dg 1000 or a dm32, if you already own this equipment, these gauges support that kind of measurements right and then this one is available.

If you, if you're just getting started, that's our model. This is how we think about it. You know you guys are are moving up, you guys are moving up this pyramid and, if you're not ready to go all the way into this, add somebody to your team. You know if you're a contractor, you say i've got sales guys.

I've got install and commission guys. I got service guys and i at least better know a home performance guy. We know a real, really good one thanks for watching this video again to find out everything we have going on. You can download the free hvac school app on android or on iphone or go to hvacrschool.com and then, specifically up in the top you'll, see events to find out more about upcoming symposiums hope to see you there thanks for watching our video.

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