American HPACO-45 1**+AXST-50S 1**

It holds 46 gallons in the test, 1 gallon more than its 45-gallon sold size. It delivers 70 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. In the first hour, 251 of the 481 heat pump models give more hot water. The median heat pump model gives 72 gallons in the first hour of the test.

It has 2 model numbers that are ENERGY STAR certified. In the test, it delivered 3.52 units of hot water energy for each unit used (its UEF). It moves heat from the air rather than making it, so its UEF passes 1. The daily hot water use in the test, called its draw pattern, was medium. Of 226 heat pump models with the same draw pattern, 143 have a higher UEF. On its draw pattern, the median heat pump UEF is 3.68. While it reheats, the water gains 429% of the energy it uses (its recovery efficiency).

It is the basic model for MHPCO-45 1**+MXST-50S 1** and MHPCO-45 1**+MXST-50STTP 1**. There are 8 more basic models with the same test figures. Between them, those basic models carry 7 other brand names. For the full group, see the A. O. Smith HPACO-45 1**+AXST-50S 1** page.

It may qualify for 17 rebate programs in 17 states. Another 5 rebate programs may accept it if it meets their other terms.