Rinnai REHP65BM

It holds 60 gallons in the test, 5 gallons less than its 65-gallon sold size. Starting full, it gives 80 gallons of hot water in its first hour of use. That is 20 gallons more than its tank holds, since it reheats during the hour. Of 481 heat pump models, 146 give more hot water in the first hour. The median heat pump model gives 72 gallons in its first hour.

Its single model number, REHP65BM, is ENERGY STAR certified. In the test, it gives 3.90 units of hot water energy per unit it uses (its UEF). It moves heat from the air rather than making it, so its UEF passes 1. In the test, daily hot water use was set to high (its draw pattern). Of 237 heat pump models with the same draw pattern, 97 have a higher UEF. For its type and draw pattern, the median UEF is 3.88. When it reheats water in the test, the water gains 450% of the energy it uses.

Its test figures match those of 13 other basic models. Besides this brand, 9 brands list one or more of them. For the full group, see the Rinnai REHP65.

It may qualify for 20 rebate programs in 19 states. Another 7 rebate programs may accept it if it meets their other terms.