Cold Air Return Problems
LESLIE: Pat in Delaware finds The Money Pit on WDEL. And you’ve got an air conditioning question. What can we do for you?
PAT: Yes. I have a two-story colonial home and we had central air put in not too long ago. And at the very top of our steps, that goes up to our second floor, they put a hole in the ceiling about the size of a two by two inch … I mean two foot by two foot square.
PAT: That’s the attic.
PAT: I constantly feel cold air coming down. And to me they said, “Nope, that’s how the air conditioning and the heat in the winter … everything will go through. That’s your cold duct return.”
TOM: Yeah, that’s your cold air return. When you feel this cold air, you’re standing … are you standing like right under it? Sort of at the top of your stairs?
PAT: Yeah, it’s right over my linen closet and in the hallway, right …
TOM: Well, let me tell you what could be happening. As … if that system is on … do you only feel it when the system is on or do you feel it when it’s off?
PAT: No, when it’s on.
TOM: Well, when it’s on, that has a tremendous draw of air that goes in there. Because that’s where all of this air … you know, just hundreds of square feet or of cubic feet of air is being sucked up into that. And that actually causes somewhat of a breeze. And as that air moves across your body, what happens is it causes a condition known as evaporative cooling. Basically, as the moisture – the perspiration – evaporates off your skin, you get a chill as that warm air, even though it’s warm, is being pulled across that space. So if you’re feeling this when it’s on, it might actually be doing it’s job. And especially in the air conditioning mode, it’s exactly the right place they put it.
Now the only place that air could be leaking from the attic, might be around the outside of the box. That’s easy enough to tell because you would simply go up in the attic, you’d pull back the insulation around where the cold air return is attaching to the ceiling, and you’d see if it’s sealed in that area. And if it’s not – if there’s gaps – certainly, there could be some cold air from the attic that’s leaking in there.
But most likely, I think what you’re just feeling is the draft caused by the cold air return doing it’s job.
LESLIE: Is there anything she can put on there, like a diverter, to make it so that it doesn’t blow right on her head when she’s at the linen closet?
TOM: But it’s not blowing on her head. It’s blowing by her head. That’s … the return is sucking air up. So, not really.
TOM: You follow me?
PAT: But you said something about a box?
TOM: Well, the cold air return box – the duct box – is going to be attached to the ceiling. And if you go up in the attic and look where that area is connected, you might see some gaps around there. I doubt it, but that’s possible. The other thing you could do is pull the … pull the grill off the return air duct. You could see it from … you could see it from downstairs that way, too.
If you happen to see any gaps around that, the simple way to fix that is to go out and buy some expandable foam in a can; Great Stuff or something like that. It comes in a latex version, by the way, now; which is a lot easier to use and less staining. And you simply spray it in that gap between the duct and the ceiling. And then, it’s going to expand and kind of look a bit sloppy. Don’t touch it; just let it expand and let it dry. Then you can take a utility knife and cut it nice and clean and trim it off and then put the grill back on.
PAT: Well, the only thing is when I go up in the attic, there’s no box. It’s just a square hole with the grill showing on the underneath side.
TOM: Right. There’s a duct that goes in there, though.
PAT: No. It’s just a grill laying on a square hole.
TOM: There’s got to be a duct attached to it. It wouldn’t be a cold air return without a duct.
PAT: You’re getting constant cold air in the winter and in the summer you feel the hot air.
TOM: There’s got to be something attached to it.
PAT: So if there isn’t, then there’s …
TOM: Then it’s wrong. I can’t imagine in a million years why somebody would just put a hole in your ceiling. There’s got to be a duct attached to it.
PAT: I know. They said this had to be … it had to be able so it would suck it up the stair steps …
TOM: Well, I …
PAT: … and let the air get upstairs. And I said, “Well, isn’t the cold air going to go out into the attic?” And they said, “No, because it’ll be evenly distributed when it hits the heat at the second floor.”
TOM: Well, I don’t know that that’s true. I mean you’ve got to take a careful look at that. But there’s got to be a duct attached to a cold air return or it’s not a return. Okay?
PAT: So it’s … duct work is …
TOM: If there’s a hole … if there’s a grill and hole up to your attic, it’s done wrong. But I can’t imagine in a million years why somebody would do that.
PAT: Okay, because this is an over 50-year-old home.
TOM: Doesn’t matter. There’s no reason to do it at all.
PAT: So duct work should be connected to all …
TOM: Duct work should be connected to that. The return duct should be connected to all of those registers. Yep.
PAT: I will check that out.
TOM: Alright, Pat. Thanks so much for calling us at 888-MONEY-PIT.
PAT: Thank you, sir. I love your show.
TOM: You’re welcome.