Paper No 478 – Field Experience with Residential Heat Pumps in Switzerland: Potential for Improvement and Future Developments – 14th IEA Heat Pump Conference, Chicago, USA
This study summarizes the main findings from field measurements with 14 air-to-water heat pumps (AWHP) and 12 brine-to-water heat pumps (BWHP) in Switzerland. The focus is on heat pump control optimization and possible future performance developments until 2050. The following statements can be derived so far: • AWHPs with variable-speed compressors are particularly suitable for new buildings with low supply temperatures (e.g., floor heating). • At a temperature lift of 25 K, AWHPs with inverter technology are 22 % more efficient on average than those with fixed speed. At 40 K, both compressor types operate equally efficiently. • For retrofits and higher supply temperatures, BWHPs are preferable due to their higher efficiency and more stable source temperature. However, proper sizing, integration, and parameterization are key to the efficient and durable operation. • AWHPs currently achieve a measured Seasonal Performance Factor (SPF) of 3.5 in new single-family houses (combined heating and hot water mode), while BWHPs achieve an SPF of 4.9. • In an average-case scenario (new house,