DoesTheMath

A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1** vs Midea US3-RSJ-15/190RDVN3-L4: which uses less energy?

At the medium draw pattern the Midea US3-RSJ-15/190RDVN3-L4 uses 866 kWh a year and the A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1** 915 — 49 kWh (5%) less, about 488 kWh over ten years. Both are filed as an electric tank, so the comparison holds. Enter your ZIP below to price the difference.

Side by side

Compared within one class only: models filed as an electric tank at the medium draw pattern.

Filed and computed figures
A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1** Midea US3-RSJ-15/190RDVN3-L4
UEF (Uniform Energy Factor) 3.55 3.75 (better)
Energy use per year (kWh) 915 866 (better)
First hour rating (gal) 72 71
Rated storage volume (gal) 48 46
Installed cost range $3,099–$4,228 $3,057–$4,409
ENERGY STAR certified yes yes
Sound level (dB) not filed 49
Refrigerant R-744 (CO2), GWP 1 R-134a, GWP 1430
On the market since 2026-02-13 2026-06-30
DOE CCD · 2026-09-19

What it costs to run

A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1**: 915 kWh a year Midea US3-RSJ-15/190RDVN3-L4: 866 kWh a year

A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1** — 915 kWh a year Midea US3-RSJ-15/190RDVN3-L4 — 866 kWh a year

Midea US3-RSJ-15/190RDVN3-L4 is 49 kWh a year lower than A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1**.

DOE CCD · 2026-09-19

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Reliability

Not published: Reliability, failure rates and each model’s actual warranty term.

The registries these figures come from certify energy performance under a federal test; none of them records how long a unit lasts or how often it fails, so this page does not rank the two on reliability.

What is here instead:

  • The filed efficiency, capacity and tank size of both models, side by side below.
  • Both are ENERGY STAR certified, which requires a manufacturer warranty of at least six years; the actual term for each model is not published.
  • Time on the market, as filed with ENERGY STAR: the A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1** since 2026-02-13, the Midea US3-RSJ-15/190RDVN3-L4 since 2026-06-30. A sale date, not a lifespan.

Which should you pick?

  • Pick the Midea US3-RSJ-15/190RDVN3-L4 if running cost matters most: it uses 49 kWh less a year on the same test.
  • Pick the A. O. SMITH HPACO-45 1**+AXST-50LBTTP 1** if you need more hot water in your busiest hour: it lists a first hour rating of 72 gallons against 71.
  • Neither if your household's busiest hour needs more than 72 gallons of hot water — neither lists more. Check whether a 50-gallon heater is enough.

Each model on its own

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