by When Trevor and Doreen moved into their Cotswolds bungalow eight years ago, they were impressed by some of the green features left behind by their eco-minded predecessors.
“Our solar thermal energy [panels] They work great, solar PV allows us to make some money back from time to time,” says Trevor.
But the heat pump installed to replace the old oil boiler turned out to be a disappointment.
“The heat pump was never enough for us,” he says.
Poor installation meant the heat pump was too small for the six-bedroom house, leaving them with inadequate radiator temperatures, lukewarm water and huge bills.
Furthermore, the device made a lot of noise. “It was a howl,” Trevor says. “We have three acres and when you were at the bottom of the garden, you could hear the heater running.”
The Government wants 600,000 heat pumps to be installed annually by 2028 to help meet its net zero targets. But uptake has so far been slow, prompting the Government to increase its grant offers to individual households from £5,000 to £7,500, and to allocate an extra £1.5bn to the scheme.
Among the possible dangers, noise from heat pumps has been raised as a possible problem that is causing households to hesitate about this technology.
Current planning rules say that sound levels from a heat pump should not exceed 42 dB when measured one meter from your neighbor’s nearest door or window, about the same level as a refrigerator. But a recent report for the Government by consultancy Apex Acoustics found that some of the loudest models of heat pumps should be located at least 4 meters away to meet the standards set by the Microgeneration Certification Programme, which must be met to qualify for grants. .
A recent review of noise emissions from air source heat pumps for the Government found that noise appeared to be a concern for only a minority of people who have installations. He said the few noise complaints that had been made were a result of poor quality facilities, including location and proximity to nearby rooms.
But for those few installations, noise issues could prove decisive and potentially affect an owner’s likelihood of keeping a heat pump or recommending it to others.
Trevor and Doreen eventually got rid of theirs and replaced it with an oil boiler, although noise was not a deal breaker compared to the model’s running cost, which was around £800 a month.
“[The noise] “It wasn’t really important to us, because our neighbors are quite far away,” says Trevor. “However, if we had been on a terrace, you could have imagined that it could have been disturbing.”
The couple were so affected by the experience that they bought a second backup diesel boiler to install in case their current model breaks down, in case the Government bans the installation of fossil fuel devices by 2035.
For Mike Henshaw, the solution has not been so simple. Last year, his next-door neighbor installed an air-source heat pump and air conditioning unit on the first floor, about fifteen feet from Henshaw’s bedroom window.
“The noise levels coming from the air source heat pump are quite horrendous, even when we are so far away,” he says.
“Imagine a farm with 1,000 air source heat pumps running at full capacity in the middle of winter, when it’s very cold. “The noise would be pretty awful.”
An independent noise assessment carried out at the property, a detached house not far from Nottingham, found that the Mitsubishi heat pump had a weighted dB level of 53 at 1m distance, significantly above the recommended level. Henshaw says the heat pump appeared to be running at a noisier level than advertised during colder periods.
“It is a mechanical device; “The more you load it, the more noise it makes,” he says. “And that’s what happens to these heat pumps in the winter, when it’s cold outside: They’re considerably louder.”
The heat pump is loud enough to significantly reduce Henshaw and her family’s ability to enjoy both their indoor and outdoor space.
“If you go out of the house into the yard, you can hear it very loud,” he said. “You can hear the hum of the unit inside the bedroom, and below that bedroom is our TV music room. And there is also a humming noise. So it basically takes away our comforts.”
Mitsubishi said its heat pumps “meet the highest standards” and are evaluated under test conditions. He added that it was unclear whether the installation by Henshaw’s neighbor included the recommended anti-vibration feet and said the air conditioning unit would increase noise levels.
“Without knowing more about this particular installation, we cannot comment further,” said Russell Dean, director of Mitsubishi Electric’s residential products group.
Jack Harvie-Clark of Apex Acoustics, who conducted the report that made headlines earlier this year, says noise doesn’t have to be a problem for heat pump homes. “Noise needs to be taken into account, but it is not an obstacle,” he says.
Newer models are getting quieter and many are joining the Quietmark program, which identifies the quietest models on the market, but a big part of the problem is how difficult it is for potential customers to find out how noisy their pump may be. heat. be.
“I spend half my life looking for that data, and the way air source heat pumps are described is incredibly difficult even for me,” he says. “At the moment we don’t know how loud the loud ones are and how quiet the quiet ones are.”
Emma Bohan, who runs installation company IMS Heat Pumps, agrees that it is becoming more of a “nothing”.
“All the major brands have seen that this is a huge concern for owners and have worked to address it,” he says.
“Older units have been louder in the past, but the modern units that are taking off are as quiet as possible. Not even Dyson has invented a silent fan and it is the king of fans.”
“In most cases, smoke from a gas boiler is louder than smoke from a heat pump, but you can’t hear it because it’s outside.”
But he acknowledges there are still some unknowns about the impact of a mass rollout in the UK, particularly on housing estates where every home could have a heat pump.
“That is the unknown. “It hasn’t been tested yet,” she stated.
