What's your experience with heat pump hot water heater noise?

May 18, 2022 1:26 PM

Our gas hot water heater is reaching the end of its life and we're looking at replacing it with a heat pump water heater (likely either a Bradford White or Rheem/Ruud). One of the hardest parts of the decision-making process for us has been determining if the additional noise produced by the heat pump is going to be bothersome to us. If you have one of these what has your experience been with noise?

We're looking at a heat pump both for environmental reasons and because we're considering putting in solar in the relatively near future.

A lot of people say the noise is a low hum and through an insulated wall they can barely hear it, but then there are threads like this one with people saying they can hear theirs loudly throughout their entire home. It's also hard to tell from dB numbers what they actually sound like.

Our installation would be in the garage with an insulated wall between the heater and our dining room and an access door with no insulation between the water heater and our backyard deck.

We're located in East Bay Area in California in case that's relevant.

posted by unus sum to Home & Garden (7 answers total)

We have ours (a Rheem) in an open laundry closet/room adjacent to the kitchen. From the kitchen I can tell if it's running, but it's quieter than the range hood, quieter than either dryer or washer, about the same as dishwasher I think. Can't hear it at all in the rest of the house.
posted by supercres at 1:40 PM on May 18, 2022

In the room directly above ours, which has a newer wood floor on top of old planks that are exposed from below, we can hear it at about the same level as one can hear refrigerators doing their thing in the same room. It can vaguely be heard from adjacent rooms on the same level of the house, but not in a bothersome way except that since it's in the middle in one direction, it can make it difficult to hear (some) people talking from one side to the other. Not because it's so loud, just because it can be difficult to pick out words clearly when talking over that distance is already a bit of a stretch. It cannot be heard from the next level of the house.
posted by teremala at 2:05 PM on May 18, 2022

I have a hum through the house, which varies in pitch depending on the fan speed of the exchanger.

That said, the hum is still a lot quieter than the gas furnace we used to have.
posted by They sucked his brains out! at 3:18 PM on May 18, 2022

I recently replaced my gas hot water with a heat pump (enviroheat). It sits outside the house on the deck. In my (small, single-glazed, poorly insulated) house I can hear the heater throughout when it is running, but it doesn't bother me. It runs during the day since I have solar, and takes several hours to heat. The noise level is similar to the gas ducted heating when it is running. For reference, the stated noise level is 46 dBA, the leading model in Australia for low noise, from Sanden, is 37dB.

I wasn't too worried about the noise because I knew it was going to be running during the day when I am mostly not here, and I wanted something relatively energy efficient. But my parents recently replaced their electric storage water heater with another electric model, because they find the noise of my heat pump version irritating.
posted by neatsocks at 3:27 PM on May 18, 2022

The noise is a thing. We can hear ours (Rheem) upstairs. You can cut the noise significantly by insulating in the area where the water heater sits. If you really want, you can put an insulated or carpeted cardboard box on top that will significantly muffle the condenser and fan noise without restricting airflow.
posted by michaelh at 3:36 PM on May 18, 2022

Rheem messed up and a lot of the units manufactured in the last couple years have been quite loud. They now have a warranty program to either replace the fan or replace the whole unit, depending on the cause of the problem. Ours is definitely loud and we are in the process of having it dealt with, so I can't comment on the final volume level. But if you're reading threads about very loud Rheem units, it's probably the bad ones from the last couple years — apparently the new ones manufactured in the last few months are no longer as loud.

I think with yours in the garage, you should be fine.
posted by ssg at 1:08 AM on May 19, 2022

We have a Mitsubish Ecodan heat pump and hot water cylinder, which is under the stairs in our three bedroom, two floor brick home in Scotland. When you’re in the back porch by the stair cupboard, you can always hear a low hum. When the heat pump is working hard in the winter, it’s audible in the kitchen and, if it’s very quiet in the middle of the night, in our living room or at the top of the stairs. With doors closed or if there’s any other noise (like wind) I don’t hear it.

It’s probably about half as loud as our old gas boiler? But it runs constantly, rather than the hour or two a day that the gas boiler did. The hot water cylinder hums all the time, even in summer when the heat pump itself isn’t running.

The heat pump itself is louder, but the sound dissipates very quickly - our back garden is about 10 metres long and if I stand at the back of the garden when it’s going full blast, I can just hear it.

Quality of life-wise, I totally recommend them, especially if you are considering solar (so are we). We both work from home, so heating the house with gas would be incredibly expensive - when we had a gas boiler the house never really got warm apart from an hour or two a day. We spend a bit more now (although it’s really hard to tell how much, since the energy market in the UK is completely insane just now) but the house is comfortably warm all the time. I’m hoping that if/when we get solar it will be a very cheap way to heat the house.
posted by Happy Dave at 12:12 PM on May 19, 2022