Heat pumps could address the world’s heating and cooling needs and eliminate almost all emissions if powered by renewable energy. If you own a refrigerator, you already have a heat pump. Heat pumps and refrigerators both have a compressor, condenser, expansion valve, and evaporator.
Heat pumps can supply indoor heating, cooling, and hot water—all from one integrated unit. Redmond could require the installation of ENERGY STAR-certified heat-pump water heaters for most domestic hot water use. New electric heat-pump water heaters can be 2 to 3 times more energy efficient than the traditional gas or electric-resistance types. The requirement would, of course, be unnecessary if the residence is in a building which is connected to a district heating system. If the City does not intend to try district heating, then individualized heat pumps can do the water heating, air conditioning, and space heating of a building.