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

It holds 46 gallons in the test, 1 gallon more than its 45-gallon sold size. Over one hour from a full tank, it gave 70 gallons in the test (its first-hour rating). Reheating lets it give 24 gallons beyond the 46 gallons in its tank. 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.

Under this basic model, 2 model numbers are ENERGY STAR certified. For each unit of energy it uses, 3.52 units end up in the hot water (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. Among 226 heat pump models on its draw pattern, 143 have a higher UEF. For its type and draw pattern, the median UEF is 3.68. When it reheats water in the test, the water gains 429% of the energy it uses.

It is sold as SHPCO-45 1**+SXST-50S 1** and SHPCO-45 1**+SXST-50SG 1**. Its test figures match those of 8 other basic models. Between them, those basic models carry 7 other brand names. You can find the whole group on the page for the A. O. Smith HPACO-45 1**+AXST-50S 1**.

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