ASHP Sound Ratings
Air source heat pump manufacturers rate their heat pumps in decibels (db), weighted sound power (overall noise emitted), and sound pressure (perceived level at a set distance, usually 1 m). Typical modern ASHPs operate between 45 db and 60 db at full load. This might sound substantial, but that’s roughly the same intensity of a quiet conversation, or the background din of the average office.
Biggest Factors Affecting Noise
When looking at various models of air source heat pumps, the details may seem overwhelming, but it’s important to remember that the noise level of the unit will depend on three main variables:
- Compressor Size & Type: Larger capacity units often run slightly louder under peak load. Inverter‑driven compressors modulate speed and can reduce noise at partial load.
- Fan Design: Multi‑speed or variable‑speed fans adjust airflow to match demand, lowering sound when ambient temperatures are mild.
- Mounting & Location: Poorly isolated installations can transmit vibration into the building structure. Outdoor units placed near bedroom windows or on lightweight walls may seem louder indoors.
Noise Reduction Strategies
- Acoustic mounts, anti-vibration mounts or simple rubber pads can help decouple the unit from its base. This lowers structure-borne noise.
- Positioning the outdoor unit at least 1m from living spaces and using acoustic screening or louvred panels to help deflect sound away.
- Regular maintenance tasks like cleaning the fan blades and coils can help prevent airflow restriction, which can impact fan health and noise over time.
Doing Your Comparison
When choosing the right ASHP for your needs, make sure you look at both the db sound pressure at 1m and the sound power levels. Differences of just 3 db over a metre are enough to double or halve perceived loudness, so look for lower rated sound power and inverter-driven modulation for quieter operation.
Live More Comfortably With An ASHP
For expert advice on selecting and installing a low‑noise air source heat pump, enquire with Air To Heat online, or call us on 0208 936 7639.
