In this video, we have Chris Hughes From the Energy Conservatory We have Adam 18 Adam As he's known long-time contributor to Hvec school, he's written for us and he helps me out with a lot of things and special guest. George Talking about how to measure duck leakage to the outside quickly and easily I Think you're going to enjoy this. We got some work to do today. It's outside testing.

Let's go go to work. so we're at my brother's house in Louisiana I Dragged you over both you over a whole what five? ten minutes, right? George Suited up, he was ready to go. He's been excited to do some testing now for a while. He's ready to get paid All right.

George Yeah and this is kind of a rush job because they're out of the house for about an hour. Yeah, so yeah. So I was in Minneapolis What? four or five Six months ago doing the training. the Tec training where we were learning about um, sensible heat ratio? yeah, duck Blaster Blower door and I had a hard time initially wrapping my mind around.

uh, duck leakage to outside? Yeah, Duck League is outside is not the easiest one to explain and there's no script here. so we're going to try to ad-lib this whole conversation to try to figure if we see if we can explain it cleanly right here. We may have to throw some annotations in this video to clean up some of this, but let's give it a let's give it a shot. Cool.

So what we're going to do is we're setting up a blower door and a duck Blaster Right, We're gonna set the blower door to run at negative 25 pascals. that's with reference to outside Am I Saying that Correct. Correct. We want the whole house.

We want the thermal envelope to be at negative 25 pascals and referenced outside. Okay, and at the same time we masked off, masked off all of the the registers and return grills in the house and now we're going to hook up a duck Blaster and run that to run it. You know, zero Pascals or negative 25 Pascals and referenced outside as well. The reason we say Crew Zero, you'll hear that a lot is what we're meaning is we're cruising Zero meaning the duck blasters matching the Um from the input channel on channel A in reference to the second port on channel A which is reading the house pressure which is negative which is negative 25.

We want to get the duct system down to negative 25 which those pressure should then matching that's cruising zero so we could run a tube from the reference board to outside as well and make the duct Blaster go to negative 25 which some people might think that's easier to understand, but it's a little bit more work, right? I Look easy I Like easy and we're in a hurry. So okay. The part that's a little tricky on this to understand is we're kind of creating an air barrier between. It's almost like putting a patch on a piece of pipe.

right. We're neutralizing. We're neutralizing pressures. So imagine you had a house that you tested on a Total Ducklings test and it was 200 CFM Leakage? That's a lot.

You don't want to leave that like that. Um, so if we have a house that's got that kind of leakage, but what if two three fourths of that is leaking inside the thermal boundary and you only have 50 CFM of leakage to outside the thermal boundary? would you chase leakage at that point to I Mean it depends like you know, but uh, I Think maybe Yes, maybe no depending on where you're at. and if you're going to pass code or not, right? Correct. so there is.

There is a big push to make duck leashed outside a code test. In some areas, it may be a test. Some areas, it's definitely not like. Here's definitely not: Um, we were barely kind of getting to duck leakage Total duck leakage testing.

but it's a good test to know how much of your duck leakages outside the thermal boundary. That's what you're trying to prove because we don't want duck leakage at all. But we definitely don't want duck leakage to leave outside the thermal envelope. Because when we leave, when we pay for conditioner and it leaves a thermal envelope, every CFM that goes out brings one CFM in.

It's a double whammy situation. You lose capacity and you increase the load and that's really bad. So duck leakage inside the thermal envelope could lead to comfort problems. Duckly gets to outside.

the thermal envelope is comfortable problems followed by destruction. You know, mold? Different things like that are going to affect the house. So we're not talking about just a hot bedroom. We're talking about potentially hot bedrooms and wood getting wet.

moldy. You know, Bigger problems. Nothing good, nothing good. You ready to go to work? Yep, let's do this now.

We're gonna turn on the blower door to get the house down to negative 25 pascals of pressure. So we're gonna hit Tubing Assistants building tightness and depressurize inside the building. Model 3 Fan Continue and we hit play. Now we hit set Baseline Okay, now we hit enter.

We gotta change it to 20 Flow 25 CF in. So we're going to turn on the speed controller and we're gonna hit play now. I'm gonna send it over to my dad. Okay, so George has the blower door running at negative 25 pascals of pressure over there on the exterior door Now I've already captured the Baseline on this gauge which is running my duck Blaster here.

but I Went back to the beginning just to show you how to get through tubing assistant on this one. we'll go tubing assistant uh, duct tightness leakage to outside. We're going to do depressurization. The gauge is inside the building.

we're using the dark Blaster B Fan: We're going to confirm our selections, right? Continue. And we've already set up our tubing where it goes and we've masked off all our grills. We did that earlier. Now we hit play now.

I Can set my cruise to zero right and you'll notice I have this pressure here on the left side of the screen right. Remember I've captured my Baseline earlier. You need to set the Baseline with the blower door setting. its Baseline here.

So we've got a pressure here. What does that mean? That means that the duct system in this house is currently at not at negative 25 pascals of pressure. If we crew zero, which is the same thing as negative 25 pressure in compared outside being our references in the home, we would need to get this to zero to do that. So we're going to cruise zero, Turn on our speed controller.

we've got it set for zero. We're going to hit play and now what that's going to do is going to ramp up the duct blaster to pull the duct system to negative 25 pascals of pressure to match the house pressure. So as that ramps as you see the pressure's coming down on the left side of the screen, it's going to get to zero when it gets to zero. The CFM reading on the right side of the screen that is the leakage that is outside the thermal boundary in this home.

Currently that is our duck leakage 2 outside not our total duck leakage which is about 60. CFM All I want to know is who's buying lunch. What you think you've earned enough for lunch wasn't so bad was it was that hard? George Okay, I think like watching it happen. uh, makes it a lot more real and easier to understand for sure.

Yeah, reading about it. Um I Think conceptually, it's um, it's a tough read if you do it and you get through the workflow one good time. Conceptually, it starts to really make sense and it's easier to understand. but if you've just read it, you haven't tried it.

I Think it's a mountain equine? Yeah for sure. Yep. well I appreciate both you guys helping me out on this fist pump. George we did that.

Big thanks to Chris George and Adam for making this happen. Big thanks to The Energy Conservatory for being a great long-term partner of HVAC school. A lot of times people will see different brands and they'll Wonder like is it are they a sponsor? How does this all work? But the Energy Conservatory is just a company that I I like what they do I'm a big fan of Steve Rogers and Bill Graber over there and then also Chris Hughes Absolutely great guy. They made great tools and more importantly, great solutions for our industry.

It's a big thanks to them and thanks again to Chris Adam and George thanks for watching our video if you enjoyed it and got something out of it. If you wouldn't mind hitting the thumbs up button to like the video, subscribe to the channel and click the notifications Bell to be notified when new videos come out. HVAC School is far more than a YouTube channel. You can find out more by going to Hvacreschool.com which is our website and hub for all of our content including Tech Tips, videos, podcasts, and so much more.

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