Derek Cole answers homeowner questions about HVAC returns and dehumidification. North Carolina now requires two returns for homes over 1,600 square feet. He explains why multiple returns improve airflow and energy savings, and when you need a separate crawl-space dehumidifier versus relying on your AC unit.
Questions this episode answers
Almost 1,700 square feet (about 1,700 sq ft).
In 2008 or 2009 North Carolina code changed to require two returns for homes over 1,600 square feet.
When the crawl space is sealed (sealed crawl space).
The air conditioner (AC) functions as the dehumidifier for the home.
Chapters
Hey, on this episode, why do I need two returns in my house? And do I also need a dehumidifier? You ask your comfort and energy questions and they get answered. This is the Ask Derrick Cole Show. Hey, this is Derrick Cole. Welcome to episode 82 of the Ask Derrick Cole show. Answering our home and energy questions. And today we have a question from the woman behind the camera. Because she had a few days off, one of us was on vacation last week. We couldn't film the show. She was moving into her new house and she has this question.
I moved into my almost 1700 square feet home and have two returns. My other house had one return. Why do I have two?
In 2008 or 9, they changed the code in North Carolina. Anything over 1600 square feet, you have to have two returns. The home instead of one return. The house is big enough and I would always recommend having multiple returns because out of 15 years, I've never been to the home and been like, wow, we have too many returns here. That's never been the case. What has been the case most of the time is you go to a house, you say there's not enough return here. Stop shutting that door. You don't have return. The returns will on this side of the house. So with two returns in this 1700 square foot house, we'll say you probably have one return on one side and one return on the other side. So probably how it's laid out is that you have a room or bedrooms on this side. With the return, you have the kitchen, living room in the middle, and on this side you have rooms and a bedroom with another return. See, I haven't even seen the house. So that's why you have two returns. You want to make it as easy as possible for the air to, to get back to the unit. So the bigger the return and the more you have in these different locations where it can be closed off, the better. Because you want to make it very easy. Otherwise the unit is going to get the air it needs. It's going to suck it through the crawl space to the attic to the outside. It's going to get the air it wants to get to operate, but you want to control it. You want it to be cool, warm, filtered air from your return, not from the outside, which is unconditioned air. Right. So that'll save you energy and the unit will not have to work as hard to get the air back to it. So that is why you have two returns. Two returns is not a bad thing. I'm glad you have Two returns. Because you need two returns. Because if you have that one return on this side of the house and you had this other 1600 square feet, all that air has to get back to this side of the house one way or another. And we all know it's going to be very difficult on that back room when you shut the door, because that's your junk room. You have all your stuff in there. You don't want people to see it. It's going to be very hard for the air that's coming out to then get back to the return. Is it, Is there a junk?
Do I need a dehumidifier in my house?
Everybody needs a dehumidifier in their homes. I'm not being sarcastic, but it's called your air conditioner. That is a dehumidifier. That's what makes you feel comfortable. When it's nice and muggy and hot outside, you feel nice and cool inside because you're removing the heat from the home. But it's also dehumidifying at the same time. So what we run to a lot in this area is you do need dehumidifier in the crawl space if it's sealed. Now, if it's not sealed, you don't need a dehumidifier because then you're dehumidifying the whole world, which is not really gonna work out in your favor. You're just gonna run, run, run, run. But if your home is properly insulated, properly sized unit in your house, then your AC should reach that set point and should keep you comfortable. It's something you notice. And the reason we're getting this question, something you notice a lot more in the summertime when it's hot and muggy versus the wintertime when it's, you know, humidity is kind of like a blanket. Humidity keeps you nice and toasty. So in the wintertime, obviously we don't have many complaints about, you know, something humid in here. No, you don't hear that call, but you do hear it in the summertime. So you need to make sure your unit is sized properly for the home. I've gotten quite a few questions of, you know what? I like to get my home at 68. Can I just put a 5 ton unit in and be done with it? No, because for one reason, you have a 3 ton system and you have a 3 ton duct system. So if you put a 5 ton unit on a 3 ton duct system, you still have a 3 ton duct system. So it makes no sense to do that. Plus if the unit is too big for the home, it's not going to probably dehumidify. Yes, it's going to hit that temperature set point in the home, but you're not going to be comfortable because it's going to come on and off, on and off. You've been to those bigger commercial buildings or courthouses where it feels kind of cold and clammy, and it's because it's not dehumidifying. That's why you're getting that feeling. So you don't want that feeling inside your house. So, yes, use your dehumidifier, your air conditioner in your home, but it needs to be properly sized so you're comfortable. All right. That's episode 82 of the Ask Derrick Cole Show. Be sure to hashtag your questions. Ask Derrick Cole and we'll get him on the show. By.
