A. O. SMITH HPTA-50 2** vs AMERICAN STANDARD WATER HEATERS ARIHPWH-50: which uses less energy?

At the medium draw pattern the AMERICAN STANDARD WATER HEATERS ARIHPWH-50 uses 866 kWh a year and the A. O. SMITH HPTA-50 2** 883 — 16 kWh (2%) less, about 165 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
Figure	A. O. SMITH HPTA-50 2**	AMERICAN STANDARD WATER HEATERS ARIHPWH-50
UEF (Uniform Energy Factor)	3.68	3.75 (better)
Energy use per year (kWh)	883	866 (better)
First hour rating (gal)	65	68
Rated storage volume (gal)	46	45
Installed cost range	$3,049–$4,340	$3,024–$4,400
ENERGY STAR certified	yes	yes
Refrigerant	R-134a, GWP 1430	R-134a, GWP 1430
On the market since	2024-03-01	2023-01-01

DOE CCD · 2026-09-19

What it costs to run

A. O. SMITH HPTA-50 2** — 883 kWh a year AMERICAN STANDARD WATER HEATERS ARIHPWH-50 — 866 kWh a year

AMERICAN STANDARD WATER HEATERS ARIHPWH-50 is 17 kWh a year lower than A. O. SMITH HPTA-50 2**.

DOE CCD · 2026-09-19

Report an issue with this number

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 AMERICAN STANDARD WATER HEATERS ARIHPWH-50 since 2023-01-01. A sale date, not a lifespan.

Which should you pick?

Pick the AMERICAN STANDARD WATER HEATERS ARIHPWH-50 if running cost matters most: it uses 16 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 AMERICAN STANDARD WATER HEATERS ARIHPWH-50.
Neither if your household's busiest hour needs more than 68 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.

Each model on its own

A. O. SMITH HPTA-50 2**

Its filed figures, class position and running cost on your ZIP.
AMERICAN STANDARD WATER HEATERS ARIHPWH-50

Its filed figures, class position and running cost on your ZIP.