Heat
pump water heaters operate on the same principle as space conditioning heat
pumps, moving rather than creating heat. Powered by electricity
and using the same refrigeration process used by your air conditioner or refrigerator,
they remove heat from the surrounding air and reject it into the water in a
storage tank. Because they are simply moving heat from one place to another
as opposed to creating the heat directly they are generally two or three times
more efficient than resistance electricity. During the warmer months, heat pump
water heaters located inside the home have an added advantage: they cool the
air that passes over their heat exchanger coils just like an air conditioner.
This feature has made them popular in commercial kitchens and in warm climates
where the cooling is appreciated year ‘round. Because their initial cost
is usually higher than other alternatives, they have had limited the acceptance
in residential settings.
Heat
pump water heaters come in two varieties. One variety is an add-on to an existing
storage water heater. The other is called integral because the heat pump is
incorporated into the storage tank making it one unit.
