I just got a new furnace in my 800 sq. ft apartment. Single stage 80% efficiency 40K BTU Coleman.
It seems much louder than my old one. The burners and the blower. And when I walk past the (single) air intake in the front room (which happens to be at head level), it seems to kind of hurt my eardrums/put pressure on my head somehow, when it's on. There is definitely a lot blowing relative to the old one. After a few minutes of it blowing, however, the "air pressure" sensation in my head goes away. Odd.
The single air intake is basically a couple of feet above the furnace itself, at head level.
A few other random clues: it sends air "down" into the ducts under the foundation, however it seems to leak from the edges of the unit and blow hot air "into" the utility closet. Also makes a ticking noise and seems to shake wall when blower on (shake it a tiny bit).
I'm also afraid of it being so loud people will have to turn the TV up and down for it. Most of the sound seems to be coming from "air" noise/volume/pressure.
Any ideas (either on air pressure or noise)? Larger intake (current is 14×20)?) Would a larger intake allow for better "heat rise" [temperature differential] across the heat exchanger?
Best Answer
I installed a "decibel meter" app on my phone and it seems to show that the noise level generated is not abnormal, relative to others like it (it's still louder than I'd like). I was able to have the furnace guys that installed it change the "fan speed" setting, apparently for heat there were two options "high high" or "med high" and the default was high high (apparently for cooling there is only "one" option "super high" but I don't have A/C so haven't experienced that).
Another work around is to just not walk "past the intake" and I'm OK (or not put a couch next to it), though I haven't experimented totally with these options yet.
Other options: use a furnace filter that prohibits air flow (but then they get dirtier more quickly), or add a piece of paper the intake so it can't get air in as quickly (just be careful to not block it too much because if the heat exchanger gets too hot, because it doesn't get cooled with as much air, the furnace will shut off so you'll have to test it out first and make sure this doesn't happen, suggest running it an hour straight to make sure).
If its too much air pressure in the bedroom, I found out that our door lacked a gap underneath it that was large enough to "let air out" as it were (so I could cut off some more from the bottom of the door to make it match the others in the house), and you could also close the vents in that room.
Other options: install variable or two stage furnace. I'm not sure if two stage would actually be helpful since the furnace man says it just runs as "high high" and "high med" for low anyway, but it's possible he was mistaken. Two stage might run "more often" as it were, as well, FWIW, so unclear there. It seems from my research that "two stage" furnaces mostly refers to a "two stage" gas release valve (i.e. 2 stage burner). The blower is separate, and might be "single stage" still, even on a "two stage burner" furnace (though frequently they're not). The blower can be "1 stage" or "2 stage" or "variable speed" (the latter being the quietest).
Also double check for CO levels in the air, also have installer make sure the ducts are "big enough" for the size of furnace.