Air source heat pumps running in the same street at the same time to heat people’s houses will not noticeably increase background noise, even in worst-case scenarios.
This is the conclusion of a study conduced by acoustics experts at Apex Acoustics and commissioned by innovation charity Nesta that looked at the potential cumulative noise impacts of multiple heat pumps installed in densely populated residential areas.
Researchers simulated scenarios with maximum possible housing densities and all heat pumps operating at full power simultaneously. Even under this ‘improbable’ condition, cumulative noise levels would remain below thresholds known to cause adverse health effects. In most scenarios, the combined noise increase of multiple units was found to be relatively modest – ranging from only 2 to 8 decibels, with the highest increase in gardens without fences.
The modelling found multiple air source heat pumps do not typically generate noise levels that would be distinguishable from that of a nearby single air source heat pump installed within MCS guidelines. This is the case even if the heat pumps generated their top noise levels at full power all at the same time in a neighbourhood with the densest possible terraced housing.
The maximum permissible noise level for a single heat pump, set by the standards body MCS, is 42 decibels (dB), as measured at the nearest neighbouring property. In light of this new report, Nesta says it supports keeping the current 42db noise limit in place.
The researchers conclude that, provided current UK noise regulations for individual heat pump installations are followed, there is no significant risk of undesirable cumulative noise impacts from widespread adoption.
Katy King, deputy director of sustainable future at Nesta, says: “Heat pumps are the most efficient way to reduce carbon emissions in people’s homes, so it’s reassuring that having one installed in every house in a neighbourhood makes almost no difference to noise levels.
“Every year manufacturers are producing quieter heat pump models and a properly installed unit is already only as audible as the hum of a fridge or the sound of a gas boiler. It’s concerning that some planning applications have factored in unevidenced worry about noise when it comes to heat pump installations. This study shows that even with all the worst-case factors in place, there is little risk of people being able to notice the sounds of multiple heat pumps running alongside each other to heat people’s houses.”
View the ‘ASHP cumulative noise impact – noise modelling study’ report here.
