In climates with moderate cooling and heating requirements, heat pumps provide a greener alternative to air conditioners and boilers.

An air source heat pump absorbs heat from the outside air and uses it to provide heat in your home; including radiators, the provision of hot water, underfloor heating systems or warm air convectors. It can also meet your home’s air conditioning needs.

An ASHP is more environmentally friendly compared with traditional heating systems, as the heat it extracts is renewed naturally – hence the only impact on the environment is the electricity it uses.

 

How do heat pumps work?

 

Air-to-water systems distribute heat through the central heating system, while air-to-air systems produce warm air that’s circulated by fans through your home.

Systems involving heat transfer use an external condenser unit to convert the substance from gaseous to liquid state by cooling it. Air conditioning systems have a heat exchanger section to cool and condense incoming refrigerant vapour into liquid. The compressor raises the pressure and a fan blows outside air through the heat exchanger to cool the refrigerant.

The air conditioner condenser is one of the most important components of any air conditioning system. In a cooling process, a compressor pressurises the refrigerant into a hot liquid, while in a heating process, it’s the opposite.

 

How much noise do heat pumps produce…?

 

…Anyone considering heat pump installation will ask this question. The environmentally friendly technology and savings on energy bills are a bonus but noise can be an issue, as heat pumps generally produce noise levels of 40 to 50dB(A).

Noise in residential areas from industrial sources is normally assessed against British Standard BS 4142. If the difference between the Rating Level of the specific noise and the background noise is +5dB, it’s deemed to be of “marginal significance” and acceptable. However, a difference of +10dB or more indicates complaints are likely. Most local authorities will take action against the organisation producing the noise when it reaches this threshold.

 

Why do heat pumps make so much noise?

 

Heat pumps can be noisy due to their components. The four main elements of the heat pump – compressor, AC condenser, expansion valve and evaporator – can be heard when operating but the compressor and fan in particular may cause noise concerns.

The noise includes not only the sounds of the components operating but also the vibrations. The air can produce a noise when passing through the heat exchanger, with a variable intensity depending on the pressure. Buzzing sounds can be emitted from the AC unit and heat pump and the hum of the motor. If frost accumulates in the heat exchanger, this can produce further sounds on top of the existing fan noises. A constant hum can be the most disturbing aspect of heat pumps.

 

How to combat heat pump noise

 

If you’re planning to install an air source heat pump, Sound Planning can effectively combat the noise to protect neighbouring properties.

Our solutions include ASHP horizontal enclosures, with absorptive panels to reduce internal reverberation; front and side access panels; and high performance acoustic louvres in BS or RAL painted colours – timber cladding services available on request – to blend in with the environment. The compact, weatherproof, durable enclosures are easy to install.

Our AHSP vertical enclosures are purpose-built to surround your vertical exhaust air source heat pump system, addressing airflow requirements, noise planning restrictions and noise level requirements. They comply with British Standard 4142: 2014.