How hydronic heat pumps workAir-to-water heat pumps extract heat from outdoor air and transfer it to a water loop that distributes heat throughout the home. Because heat pumps move heat rather than generate it through combustion, they can deliver significantly higher efficiencies than traditional fossil-fuel equipment. Evaluating performance considerationsOne key difference between hydronic heat pumps and conventional boilers is water temperature. Traditional boilers typically supply water at up to 180°F, while many residential hydronic heat pumps are designed to provide water at approximately 140°F. Technological advancements supporting boiler retrofitsAdvancements in compressor and hydronic system technology are helping make hydronic heat pumps more viable for boiler retrofit applications.