Product Guide Heat-Pump Water Heaters The GE GeoSpring heat-pump water heater is a quiet model made in America. Photo: GE Appliances Behind the recommendations Related articles Behind the recommendations Related articles Heat-Pump Water Heaters Heat-pump water heaters with an Energy Factor of 2.0 or greater and a first-hour rating of 50 gallons per hour or greater More about Heat-Pump Water Heaters An Affordable Heat-Pump Water-Heater Retrofit AirTap is an affordable heat-pump module that can be retrofit onto a conventional electric or gas water heater. The unit has a first-hour rating of 42.5 gallons, an efficiency of 240%, and a GAMA-tested energy factor of 2.11. Heat-Pump Water Heaters Ready for Prime Time Heat-Pump Water Heaters Heat-pump water heaters produce more than twice as much hot water per kilowatt-hour of electricity consumed as standard electric water heaters. WatterSaver Heat-Pump Water Heater A Look at Heat Pump Water Heaters Heat Pump Water Heaters in Cold Climates: Pros and Cons While a heat-pump water heater will save significant energy on a year-round basis, be aware that in a cold climate the net performance (water heating plus space heating) will drop in the winter. Picking a Water Heater: Solar vs. Electric or Gas Is Just the Beginning Why we opted for electric water heating over a solar water heater.