How Noisy Are Hot Water Heat Pumps Really?

Noise is a common concern raised by people considering a heat pump hot water system.

People often ask questions like:

• Will it keep me awake at night?

• Will it annoy the neighbours?

• Are they as loud as an air conditioner?

These are reasonable questions. Heat pump hot water systems contain a fan and a compressor, so they do make some noise when operating. However, the reality is that in most homes, heat pump noise is far less of an issue than many people expect.

Let’s look at a few of the key facts.

Heat Pumps Should Run During the Day

While many older electric storage systems run overnight on off-peak electricity, heat pumps work differently and should run during the day.

In most situations, running the heat pump during the day makes far more sense.

There are several reasons for this.

First, many households now have solar panels. Running the heat pump during the day allows the system to use solar electricity to power the unit, which can effectively result in free hot water.

Second, the air temperature is higher during the day. Heat pumps work by extracting heat from the surrounding air, so when the air is warmer, the system can operate more efficiently. In simple terms, the unit doesn’t need to work as hard to heat the water, improving efficiency, shortening run times and extending the life of the unit.

Finally, electricity tariffs are changing in many parts of Australia. In some cases, daytime electricity can actually be cheaper than evening peak periods, especially for homes on time-of-use tariffs.

Because of these factors, there is usually no reason for a heat pump to be running at 2am outside someone’s bedroom window. Most modern systems can easily be programmed or timed so they operate during the middle of the day instead.

How Loud Are Heat Pump Systems?

A helpful way to understand heat pump noise is to compare it to something familiar.

Most outdoor air conditioning units operate in the mid-60 decibel range. Many people are used to having an air conditioner running outside their home on hot summer days.

By comparison, most heat pump hot water systems operate somewhere in the low-40 decibel range. Even the louder models tend to sit in the low-50s.

That means that in many cases, a heat pump will be significantly quieter than an air conditioner.

Of course, it’s always sensible to treat manufacturer specifications with a little caution. Some marketing material suggests certain systems are “as quiet as a fridge”. In my experience that comparison is a bit optimistic. Heat pumps are not completely silent.

But they are generally relatively modest in terms of noise output.

Some premium systems are noticeably quieter than others. For example, Reclaim heat pump systems are extremely quiet, and that’s one of the reasons they sit at the higher end of the price range.

A label detailing the level of noise emitted by my air conditioning unit.

Installation Location Matters

Like most things in plumbing, the quality of the installation makes a big difference.

Even a relatively quiet unit can become noticeable if it’s placed in the wrong area.

One customer of my heat pump hot water installation company Powrhouse had an old hot water unit a few meters away from their outside table. They told me they really enjoy having lunch outside on weekends. I suggested we think of alternatives as I wouldn’t want my peaceful Saturday lunch to be interrupted by the white noise of the heat pump.

Referring to the section above about running times, in this case we wouldn’t want the unit to be running from 12pm-2pm, so we looked at either relocating the unit (which increases the installation cost) or simply running the unit at different times. For example, they could run a morning cycle from 8am to 11am using a timer and then an afternoon cycle from 3pm – 5pm.

The vast majority of old hot water services are installed on the “dead side” of the house, so in most cases, noise and installation location don’t really matter.

What Do You Do If Your Heat Pump Is Too Noisy?

The best way to judge whether noise is an issue is to look at real-world experience.

At Powrhouse, we’ve installed more than 650 heat pump hot water systems across Melbourne homes.

Out of those hundreds of installations, we’ve received just two noise complaints.

The first involved an elderly customer who had accidentally set her system to operate at 2am. Once we adjusted the timer so the unit ran during the day instead, the problem was immediately resolved.

The second situation involved a customer who raised a concern about noise around six months after installation. The system itself was working normally, but to make sure the customer was comfortable we switched the unit into “quiet fan” mode, which reduces fan speed and operating noise. That solved the issue and the customer was happy.

Both situations were easily fixed without replacing equipment, moving the system or concluding that heat pumps don’t work.

The Bottom Line On Heat Pump Noise

Heat pump hot water systems produce some noise when operating, but in most homes it’s much less than people expect.

They are typically quieter than air conditioning units, and when installed sensibly and set to run during the day, they rarely cause problems for homeowners or neighbours.

And based on hundreds of installations, noise complaints are uncommon.

For more on choosing the right system for you, read SolarQuotes’ guide to heat pump hot water.