Ruud PROUH50 T2 CD400-SO

It holds 45 gallons in the test, 5 gallons less than its 50-gallon sold size. Starting full, it gives 67 gallons of hot water in its first hour of use. That is 22 gallons more than its tank holds, since it reheats during the hour. Of 481 heat pump models, 287 give more hot water in the first hour. The median heat pump model gives 72 gallons in its first hour.

It is ENERGY STAR certified under its single model number. For each unit of energy it uses, 3.88 units end up in the hot water (its UEF). Pulling heat from the air lets its UEF pass 1. Its test ran at the medium level of daily hot water use. Of 226 heat pump models with the same draw pattern, 6 have a higher UEF. A UEF of 3.68 is the median for its type and draw pattern. While it reheats, the water gains 430% of the energy it uses (its recovery efficiency).

There are 13 more basic models with the same test figures. Of those, one or more are under the Friedrich, Rheem, and Richmond brands. For the full group, see the Rheem PROPH50 T2 RH375-SO page.

In 20 states, 21 rebate programs may accept it. Another 7 programs may accept it if it meets their other terms.