Energy-Efficient Furnace: Noisy Vents
LESLIE: Next up, we’ve got Roger in Alaska who’s got a super-loud heater. I guess in Alaska, your heat is on a lot, so you want it to be kind of quiet.
ROGER: We bought a bed-and-breakfast up here and we’re not using it as a bed-and-breakfast; we’re just living in it.
ROGER: And one of the last things that was done to it was they replaced this old, 77-percent efficient furnace with a brand-new, cutting-edge 97-percenter. And we did a bunch of insulation work on it and everything after that, too. But one thing we notice is the vents – I mean when that thing – it’s like it’s a variable stage. And the vents seem to roar sometimes when it gets to blowing warm air.
ROGER: We haven’t had much of a use for it yet; it’s still summer. So we haven’t heard it kick on, I think, full-power. And maybe that’s it; we’re just starting to hear it. And I’m wondering, can – we’re probably going to have to contact the HVAC guys but is there anything that can be done or maybe open the ends of the – replace the floor grates with something that’s wider aperture or something? It just sounds like there’s a lot of noise coming out of it.
TOM: The one question I would have is: did they change the blower speed? Because if the blower speed is higher than it was before – and it might be necessary by – depending on the type of the high-efficiency furnace that was installed. But the blower speed was stepped up, that could make for louder air noises going through the duct system.
And second to that, it is possible to do a few things to quiet the duct systems, if they’re expanding and contracting and sort of making that oil-can popping sound. They can be reinforced to slow that down. They can also be insulated and you could add additional bracing to it to cut down vibrations. So I think you’ve got to isolate as to whether or not this is just wind speed because of the blower or is it vibration and expansion and contraction because the ducts are just sort of old and loose and like you say, potentially undersized.
So you do need to look into it a little bit deeper but rest assured that there are a couple things that you can do to probably quiet it. Although having said that, the high-efficiency systems are louder sometimes than the old ones. Because the old ones only had, really, kind of a lazy burner that lit up and then the blower that just sort of chugged along. High-efficiency systems have draft inducers, which are motors that come on and pull the gases through the system so that you’re assured of getting every single BTU out of the gas that you burn. That’s what gives you the efficiency but it does add just a bit to the noise component.
ROGER: Yeah, we don’t know the history on this thing because we just moved in. And we do know the gas bills are pretty horrendous over recent years; that was part of the disclosure in the sale of the house and all. So we’re happy to have the high-efficiency system. But like you said, maybe it’s just – it’s a requirement because of the high efficiency of it.
But yeah, we’re going to have to look into a few other things. I’m afraid that it’s going to involve getting an HVAC company in to possibly change out the squirrel-cage blower in there. And I really – it’s a new system; I’d rather not do that.
TOM: That’s something that I would not do and frankly, that would have been part of the furnace anyway, so you wouldn’t just replace that if it – those are multi-speed blowers and the fan speed can be adjusted. But that would not be part of what I would expect.
ROGER: OK. Well, I love you all’s show. I’m just worried that we may have bought a money pit up here in Alaska.
LESLIE: Oh, no.
ROGER: But we love it. I tell you, the views are gorgeous.
TOM: Well, Roger, if it turns out that’s what you did, you know the number: 888-MONEY-PIT.
ROGER: Thanks so much. I love the show.