Rheem PRO H40 T2 RH310BM

It holds 36 gallons in the test, 4 gallons less than its 40-gallon sold size. It delivers 60 gallons of hot water in the test's first hour. That is 24 gallons more than its tank holds, since it reheats during the hour. Among 481 heat pump models, 371 have a higher first-hour rating. Among heat pump models, the median first-hour rating is 72 gallons.

It has 5 model numbers that are ENERGY STAR certified. For each unit of energy it uses, 3.50 units end up in the hot water (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 medium (its draw pattern). Of 226 heat pump models with the same draw pattern, 158 have a higher UEF. For its type and draw pattern, the UEF runs from 2.59 to 4.23. When it reheats water in the test, the water gains 430% of the energy it uses.

It is sold under 4 model numbers in all. There are 4 more basic models with the same test figures. The Friedrich and Ruud brands list one or more of them.

It may qualify for 18 rebate programs. Another 6 programs may accept it if it meets their other terms.