ᐅ Is an air-to-water heat pump too noisy?

Hello everyone,

we have an air-to-water heat pump located about 5–6 m (16–20 ft) from our bedroom window. At night, we wake up due to the noise from the unit, especially during the defrost cycle, when it becomes clearly audible. The manufacturer is no longer responding and says this issue needs to be resolved through an expert report.

I took the time to borrow a semi-professional sound level meter, a PCE Instruments PCE-322A Class II sound meter.

At 11 p.m., measured from a distance of 6 m (20 ft), I recorded a background noise level of 37 dB. When the heat pump is running, the levels increase to between 45.5 dB and 46 dB. This measurement was made outside the defrost cycle.

From what I understand, this noise level seems excessive, but I am not a technician.

Could someone help me evaluate these values?

Maybe this will encourage the manufacturer to take more responsibility.

Best regards and many thanks!
Stefan

Two questions regarding this: first, what model of air-to-water heat pump is it? And second, why does the system go into defrost mode at the current temperatures?!

Regarding your measured 46dB... it primarily depends on how the 46dB was measured, but in general, 46dB is far from loud. For comparison, a refrigerator typically produces between 40 and 50dB. However, you also have to consider the type of noise emission. Fifty decibels of white noise is more pleasant than 50dB of a pure tone.

Still, I find it surprising—you shouldn’t be able to hear 46dB with the window closed.

greetz

Hello and thank you for your response.

The system is located about 50 cm (20 inches) away from a house wall. It does not enter defrost mode at the moment, but eventually it will again, and I want to address this issue. Even in normal operation mode, the system is clearly audible.

We usually sleep with the window open.

What interests me is this: Using an online noise calculator and the measured values, I arrive at a sound level of 45 dB for the system. Is that correct?

And I find 45 dB quite loud at night when it’s right outside the window. It’s not a pleasant wind noise; the system sounds like an old refrigerator. When it goes into defrost mode, I have a clearly audible high-pitched whistling sound in the bedroom.

We are located in a purely residential area, and according to the law, only 35 dB is allowed at night. So 45 dB would be significantly louder—in fact, 45 dB is perceived as twice as loud as 35 dB.

As I mentioned, I am not familiar with this, so these are my questions.

Best regards and thank you!
Stefan

Even if the device only produces 35 dB (as far as I know, measured from a distance of 10 meters (33 feet)), it doesn’t help if it is placed directly under an open bedroom window. This is simply poor planning and, in my opinion, cannot really be blamed on the device itself.

Hmm, yes, I think so too, but the opportunity has passed. I originally wanted to have the system installed in the garage, and everything was planned accordingly, but the installer convinced me by saying that I wouldn’t hear the system in the bedroom. Unfortunately, we are far from that.

It’s all very frustrating.

Thanks anyway for the responses.

It probably won’t work in the garage because the device requires airflow. In addition, a garage may act like a resonating chamber. You can most likely get the device modified for coin operation.