How heat pumps work in cold weather

"Subzero temperatures don't pose a problem for heat pumps. The refrigerants used in the heat exchanger, which transfers heat from outside a building to inside, have an extremely low boiling point below minus 40 C. That means even when it's very cold, a heat pump can absorb ambient heat from the outside air and use it to warm a building."

"Ground-source heat pumps, which extract heat from the soil or groundwater, are even more efficient. Compared with the air temperature, which fluctuates throughout the year, the temperature of soil and groundwater is generally higher and remains relatively stable. These systems tap heat from as deep as 300 meters (about 1,000 feet) underground, where temperatures stay around 10 C even if it's minus 50 C at the surface."

"Heat pumps draw on ambient warmth, making them highly efficient because most of the energy they deliver is already present in the environment and is not generated by burning fossil fuels."

Germany's ruling coalition is reconsidering parts of its renewable energy expansion and amending heating legislation due to fossil fuel industry pressure and public skepticism about heat pump technology. However, heat pumps are highly effective even in extreme cold climates. Air-source heat pumps operate successfully at temperatures as low as minus 25°C across Scandinavia and Arctic regions, with refrigerants boiling below minus 40°C enabling heat absorption from ambient air. Ground-source heat pumps prove even more efficient by extracting heat from soil and groundwater at depths reaching 300 meters, where temperatures remain around 10°C regardless of surface conditions. Heat pumps deliver superior efficiency compared to fossil fuel systems because they utilize ambient environmental heat rather than generating warmth through combustion.

Read at www.dw.com