DoesTheMath

AMERICAN STANDARD WATER HEATERS ARIHPWH-50 vs Lennox WHHP050T45MD240S****: which uses less energy?

At the medium draw pattern the Lennox WHHP050T45MD240S**** uses 848 kWh a year and the AMERICAN STANDARD WATER HEATERS ARIHPWH-50 866 — 18 kWh (2%) less, about 181 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
AMERICAN STANDARD WATER HEATERS ARIHPWH-50 Lennox WHHP050T45MD240S****
UEF (Uniform Energy Factor) 3.75 3.83 (better)
Energy use per year (kWh) 866 848 (better)
First hour rating (gal) 68 69
Rated storage volume (gal) 45 45
Installed cost range $3,024–$4,400 $3,033–$4,480
ENERGY STAR certified yes yes
Refrigerant R-134a, GWP 1430 R-513A, GWP 630
On the market since 2023-01-01 2025-12-01
DOE CCD · 2026-09-19

What it costs to run

AMERICAN STANDARD WATER HEATERS ARIHPWH-50: 866 kWh a year Lennox WHHP050T45MD240S****: 848 kWh a year

AMERICAN STANDARD WATER HEATERS ARIHPWH-50 — 866 kWh a year Lennox WHHP050T45MD240S**** — 848 kWh a year

Lennox WHHP050T45MD240S**** is 18 kWh a year lower than AMERICAN STANDARD WATER HEATERS ARIHPWH-50.

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 AMERICAN STANDARD WATER HEATERS ARIHPWH-50 since 2023-01-01, the Lennox WHHP050T45MD240S**** since 2025-12-01. A sale date, not a lifespan.

Which should you pick?

  • Pick the Lennox WHHP050T45MD240S**** if running cost matters most: it uses 18 kWh less a year on the same test.
  • Pick the AMERICAN STANDARD WATER HEATERS ARIHPWH-50 if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Lennox WHHP050T45MD240S****.
  • Neither if your household's busiest hour needs more than 69 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.

Each model on its own

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