DoesTheMath

A. O. SMITH HPTA-50 2** vs LOCHINVAR HPTS-50 2**: which uses less energy?

At the medium draw pattern the LOCHINVAR HPTS-50 2** uses 855 kWh a year and the A. O. SMITH HPTA-50 2** 883 — 28 kWh (3%) less, about 279 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 HPTA-50 2** LOCHINVAR HPTS-50 2**
UEF (Uniform Energy Factor) 3.68 3.8 (better)
Energy use per year (kWh) 883 855 (better)
First hour rating (gal) 65 65
Rated storage volume (gal) 46 46
Installed cost range $3,049–$4,340 $3,062–$4,459
ENERGY STAR certified yes yes
Refrigerant R-134a, GWP 1430 R-134a, GWP 1430
On the market since 2024-03-01 2022-06-06
DOE CCD · 2026-09-19

What it costs to run

A. O. SMITH HPTA-50 2**: 883 kWh a year LOCHINVAR HPTS-50 2**: 855 kWh a year

A. O. SMITH HPTA-50 2** — 883 kWh a year LOCHINVAR HPTS-50 2** — 855 kWh a year

LOCHINVAR HPTS-50 2** is 28 kWh a year lower than A. O. SMITH HPTA-50 2**.

DOE CCD · 2026-09-19

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Enter your ZIP to price both units on the same rate where you live.

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 HPTA-50 2** since 2024-03-01, the LOCHINVAR HPTS-50 2** since 2022-06-06. A sale date, not a lifespan.

Which should you pick?

  • Pick the LOCHINVAR HPTS-50 2** if running cost matters most: it uses 28 kWh less a year on the same test.
  • Pick the A. O. SMITH HPTA-50 2** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the LOCHINVAR HPTS-50 2**.
  • Neither if your household's busiest hour needs more than 65 gallons of hot water — neither lists more. Check whether a 50-gallon heater is enough.

Each model on its own

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