| > Thrilled to hear you're 6mo into life with a heat pump! It was the logical thing to do. Even before the war in Ukraine, the ROI of the heat pump was 8-10 years compared to natural gas. With current conditions, shortage of natural gas, inflation and more, the ROI is around 4 years. > Is it air-to-water and still using water/steam radiators, or forced air now? Pretty much everything regarding heat in (northern) Europe is based on water, with the exception of hotels that usually use either only air or a combination of air/water. Our particular installation is from the 1970s, meaning it's 1 string and made for much higher flow temperatures than the houses from 2000 and onwards, so instead of a 35C flow temperature we instead have a 55C flow temperature, which reduces the COP value of the heat pump. My particular model (https://www.vaillant.com/home/products/air-to-water-heat-pum...) has a COP value of (up to) 5.4 with a flow temperature of 35C, which gets reduced to around 4 with a 55C flow temperature. I've coupled mine with radiator thermostats from Tado (https://www.tado.com/gb-en/products) which use geofencing to lower the temperature when nobody is home, and they also have a "sensor/control unit" for the heat pump control itself, allowing fine grained control of the heat pump. One of their upcoming features is to try to optimize heat pump usage for when electricity is cheap. |