How noisy is your heat pump?

January 30, 2016 6:51 PM

I'm debating whether to simply replace my aging gas furnace with a more efficient one, or to add an air-source heat pump for primary heating (and cooling in summer when needed), and replace the gas furnace with a cheaper 80% efficient model for backup heat in winter.

The efficiency gain makes it seem like a no-brainer (though expensive to install), but I remember walking past houses where a heat pump was making a surprising amount of noise. It seems it can be helped somewhat by getting a model with variable speeds so that it isn't just either off or on full-blast, but I thought I'd poll the MeFites to see what your experiences have been. Location is Seattle, if it matters. Thanks!

posted by sapere aude to Home & Garden (13 answers total)

I can't imagine the noise being bothersome if you're inside your house with the windows shut. Mine is running right now and is maybe 15 feet from where I sit in my living room, but I don't notice it unless I'm listening for it specifically.
posted by something something at 7:07 PM on January 30, 2016 [1 favorite]

Replaced two 20-year-old heat pumps with new ones last year. The new ones are maybe 2/3 as loud. But I can't be sure how much of the difference has to do with improved technology vs. heat pumps getting noisier with age.
posted by Creosote at 7:17 PM on January 30, 2016

I think it depends on what type of heat pump you're considering. We have a Mitsubishi air-source "mini-split" heat pump, and the outside unit is very quiet. At its loudest it's no louder than a box fan on high. My very close next door neighbor didn't even realize we installed it.

I live in the relatively mild PNW and have no backup system for heat (except for a couple of space heaters and a fireplace). The air source heat pump has kept our small home warm even when the outside temps were in the low teens (fahrenheit). Apparently it's supposed to keep working well down to about 6 degrees F.

Used to live in a rental house with forced air gas furnace, and that was MUCH louder than the interior head of our heat pump, which mostly just emits a constant wooshing sound. Have never checked the decibels on it though.
posted by bennett being thrown at 7:25 PM on January 30, 2016

We have a Mitsubishi split system, as do our next door neighbors, and honestly I have to look at the fan blades to see if they're running.
posted by mr vino at 8:00 PM on January 30, 2016 [1 favorite]

I have a Heat Pump in Seattle, plus a 90% efficient Gas furnace as the backup source. I never hear it. The fan inside the house dwarfs the heat pump noise. If I'm in the room right next to where the heat pump is I can hear it, but it's not loud enough to matter.

Proper maintenance (clearing leaves and debris, etc) is also import.
posted by jeffamaphone at 8:10 PM on January 30, 2016

Response by poster: Ah, good clarification: it's not a mini-split I'm considering, it's the roughly cube-shaped type that sits on a concrete slab on the ground by the house. Something like the Trane XV18 or similar. And I'm more concerned with the noise outdoors than it being audible indoors. The house I mention above honestly sounded like it had a gas generator running most of the time, like you hear in an RV park or during a power outage. I'm concerned we'd never want to be out in the yard and it would piss off my neighbors.
posted by sapere aude at 8:39 PM on January 30, 2016

Another Seattle Mitsubishi split user here. It is not bad but you need to play around with it. Right now, for example, I'm currently experimenting with a different fan setting and it is certainly distracting from the TV. I will probably not use this setting again.
posted by k8t at 8:46 PM on January 30, 2016 [1 favorite]

Best answer: If you ever sit around outside in the summer then the noise will impact you at that time. My neighbor has a now 4 year old heat pump and it is have to raise your voice noisy when running in the summer time when we are on our deck 40-50ft away.

I'm sure this varies from unit to unit though.
posted by Mitheral at 1:50 AM on January 31, 2016

Best answer: We have an American Standard unit that's a year or two old and it's pretty quiet. The variable speed feature really helps too. But even at full speed it's not overwhelming.
posted by reddot at 6:07 AM on January 31, 2016

Best answer: We have them in our condo complex.

Generally, I only find it noticeable during the dead of winter, at night. A low rumble. Ours are pretty close to the bedrooms, on the other side of the wall one floor down, and I'm a light sleeper, so that's when I'm especially noise sensitive.

Given that, if you have *any* kind of problems with the fan blade / motor, then it will be loud and very annoying and will be a very high priority to fix. That might have been what you heard on that other unit.
posted by smackfu at 6:11 AM on January 31, 2016

Best answer: I have a Trane heat pump that looks like the one you linked to. It's definitely loud enough to hear inside the house when it kicks in. To be honest, I want to replace it with a gas furnace, since this heat pump does not work well (defined as the "emergency" electrical heat always coming on) whenever the temps get below 50, which is usual for my area (metro DC) in the winter.
posted by longdaysjourney at 6:54 AM on January 31, 2016

Best answer: I just went outside to listen to my 15-20 year-old Bryant (huge by modern standards) whirring away. I would not describe its sound as anything like a generator. It sounds like a couple of big box fans. It makes a louder hum when it's defrosting, and a loose screw on the housing can cause a rattle, but in normal operation I wouldn't say it's an annoying sound. We can easily have a conversation while standing next to the running unit.

I guess I'd think twice if I were installing a unit directly below a neighbor's window, but I don't think you should rule them out because of a couple of noisy examples.
posted by sageleaf at 11:28 AM on January 31, 2016

I have a five year old Daikin unit outside with two units on the inside. The only time I can hear mine is right about the quietness required to hear train horns (I'm in Madison Valley, so ~2 miles from trains). So, very very quiet. The inside units are just about fan level noise. Very tolerable.

You may have walked past my unit before I got the broken fan replaced....it was like a damn hand-vac noise level at that point, but it was a quick fix. Evergreen Heating does a great job!
posted by nursegracer at 12:18 AM on February 3, 2016