#AskDerekCole Episode 42: Airflow Challenges
28 Jan 2026 · 6 min
Derek Cole answers a caller's question about weak bedroom airflow. They discuss duct leaks and kinks as culprits, how Nest thermostats learn your schedule but have a non-replaceable battery, and when auxiliary electric heat kicks in on heat pump systems and what it costs.
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You ask your comfort and energy questions and they get answered. This is the Ask Derrick Cole Show. Hey, it's Derek Cole. Welcome to episode 42 of the Askderic Cole Show. Answering your home energy questions. Yeah, I feel pretty good. It's been a good week. First show of the week, so we're a little behind schedule, but here it comes.
I recently purchased a new house and I'm having airflow challenges to the bedrooms. Do you have any advice?
Airflow challenges in the new home? Well, could be a few things going on there. You could be losing. According to injury star, 20% on average is lost through holes and cracks in the duct system. So that's one possibility. You could be losing air that way. I personally would just go under the house, take a look at everything visually. A lot of times when they have different homes or newer homes, they have a kink or it's kind of choked off on the run of duct from the trunk line to where it's going to. You want to make sure that's flat. Even if you do have to do a turn of any kind. What we do here is we actually install a metal elbow in the duct so it can make a smoother turn than just using the flex and turning on a 90 degree angle, which kind of chokes some of your airflow off. So I would check that to see if that's happening. Also in homes, a problem we've seen before is it's not been reduced correctly going down. So if, if you go to like a Zaxby's or a Red Robin and you look up above in the ceiling, you will see the duct system. And what you'll see is a properly sized duct. You'll see it going big, small, smaller, smaller, all the way down. That's called reducing. That is a proper way to do it. That way the air pressure gets all the way down to the end of that run of trunk line, so you can have air at the end. That is a proper way to do it. That's the way we do it. That's the way it should be done. Any engineered drawings, you see, that is the way it's done. And that is a problem in most homes we've gone to because the back bedroom or the side over here is not getting the airflow. Well, it's because the pressure has dropped. And if you think about it, it's kind of like a. It's kind of like a water hose. If you have the water hose at home and you just, you know, sit it there, turn the water on the Water comes out, kind of drips out. If you put your thumb over the outlet, it'll spray a lot further. Right. Same situation. It's because of the pressure. So air is just like water and should be treated that way. So you want to make sure you keep the pressure up. But I would crawl in there and just see visually if anything is going wrong or anything's not connected. And then I would get a professional to come take a look at it.
What are your thoughts on a nest thermostat?
A nest thermostat. For those of you who don't know what a nest thermostat is, they were bought by Google for a lot of money. Was it? It was a lot of money. So it's a thermostat that you put on your wall and it's a smart thermostat. Meaning actually you don't program it. It is a program of thermostat, but it learns your habits as you have it installed. So after a week or so it realizes that, hey, they adjust the thermostat at 7am every morning, they adjust it at 8am, they adjust it at 5pm, they adjust it at 9pm Then it's going to know your habits and it will start programming for you. So I think it's a good thermostat. The downside to it is there is no way to change the batteries. If it dies, it's dead. It's a kind of a self containing product. So if anything happens to it, there's nothing you can do about it. You just have to get a new one. But I think it's a good product. I mean the problem Energy Star has had with programmable thermostats is the fact that, okay, it is code. We have to install a program of thermostat at your house. When we install a new system, the problem is people don't use the program or if they don't use it, they don't. Or if they use it, they don't use it properly. So the nest thermostat really takes that equation out of it. It learns how you operate in your house and programs for you. So it's a program thermostat where you don't have to set programs to it. It learns how you behave, it knows when you're home, it has sensors to know when it's dark outside, when it's middle of the day. It knows all this. It's got all these algorithms built into it. So it's gonna, it's gonna know what's going on. So I think it's a good thermostat, but like anything, it has a few downsides as well. And it's a big circle, you know, like the old fashioned Honeywell, big circles. So it kind of gives you that comfort of been in 1970 as well. So I think he's really good. So there you go. Was that. That was right, wasn't it?
I wasn't alive in the 70s.
That was. That was pretty much right, yeah. I like it. I got impressed when you threw up the word algorithm. I was surprised I could actually pronounce algorithm without missing notes. Yeah, big words. All right, this is a special show.
This is what is emergency?
We're black and white on all of this, by the way, so they can feel safe. We only go color when we're serious and we understand questions.
What is emergency heat and when should I actually use it?
Good question, because this is a common question. You know, my thermostat is flashing red. It says auxiliary emergency heat. What's going on? It kind of freaks a few people out, but it's fine. So when you have a heat pump or anything that's not gas, your backup heat source is the electric heat. So for example, if you had a three ton split heat pump and it was 20 degrees outside, well, there's only so much heat that that heat pump can actually get from the outside. So the rest of it, to make you comfortable, will come from the electric heat. The good thing about electricity is it's 100% efficient. You get no loss. As if you would have a gas heat, you'll be 80% efficient or 90% efficient, meaning for every dollar you spend, you get, you know, 90 cent out of it and you're losing 10 cent. So what was it? Oh, let your heat. So what is it? So it's your backup heat. It's your backup heat source. A lot of times when it comes on, you kind of smell that. It's kind of a dust burning kind of smell. When it first comes on, you're like, my house is on fire. Where everybody else is like, no, it's not. You're fine. It's just because you have maintenance, it's burning the dust off. So it's perfectly fine. So what happens is when it gets down to a certain temperature outside, the heat pump can no longer satisfy your indoor thermostat. So your electric heat is going to operate to fill that gap. So if it's whatever the gap is, it's going to fill it. There are smart heaters that should come on in different cycles. So you had a 15 canopy heat strip. So you had three banks of five. So it'd bring on five and then five and then the last five versus bringing all of them on. So you got smart heaters here, just like you would a high efficient unit. It will operate in low stage or high stage depending on demand. So it's nothing to be afraid of. The only thing I would be afraid of. Well, I'll take it back. It is, you should be afraid of it just because it's going to run your electric bill sky high the more you run it. So when it's 15, 20, 25 degrees outside, you want to lower that thermostat just a little bit, put on sweater, put on blankets. You want to keep that electric heat down from operating as much as you're comfortable with. Now if you're fine with that, you want to be comfortable, go for it. But just the disclaimer. Disclaimer, Disclaimer. Warning. Warning. You're going to lose a lot of money with electricity and running that only by itself. Good. Awesome. Episode 42, over with, done with. Thank you again for sharing the post on our one hour page on Facebook. A lot of engagement. I appreciate all of that and if you have any Questions, hashtag it AskDerrick Cole and we'll get it on the show.
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