In the past, if you wanted hot water from your heat pump, you had to buy an add-on called a desuperheater that provided part-time, partial hot water and that worked only when the heat pump was in the cooling mode. In recent years, manufacturers have introduced heat pumps with a dedicated hot water coil that supplies all of a home's year-round hot water needs. The most recent innovation is a geothermal heat pump that does nothing but heat water FHP Manufacturing of Fort Lauderdale, Florida calls its Thermal Saver 2000. It's a standard ground-source heat pump, but instead of being connected to a water-to-air coil heat exchanger, it has a water-to-water coil. The 122 MBTU system was designed specifically for homes.

According to FHP's Jason Bowes, the Thermal Saver 2000 can heat water up to 140 degrees F, can provide up to 30 gallons per hour, and can supply a radiant slab floor.

In most of the country, says Bowes, the unit will be more efficient than a standard gas or electric water heater. He estimates its coefficient of performance (COP) can go as high as 6 in temperate climates like the Northwest and Mid-Atlantic states, and 4 in the frost belt. That means users can expect $4 to $6 worth of heat for every $1 of electricity they put into the unit, which sells for about $1,000, not including installation.

Contact: FHP Manufacturing