AMERICAN PESX-40 1** vs ARISTON ARIHPWH-40: which uses less energy?
At the medium draw pattern the ARISTON ARIHPWH-40 uses 907 kWh a year and the AMERICAN PESX-40 1** 3,531 — 2,623 kWh (74%) less, about 26,234 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.
| Figure | AMERICAN PESX-40 1** | ARISTON ARIHPWH-40 |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.92 | 3.58 (better) |
| Energy use per year (kWh) | 3,531 | 907 (better) |
| First hour rating (gal) | 66 | 66 |
| Rated storage volume (gal) | 37 | 37 |
| Installed cost range | $1,605–$1,828 | not published |
| ENERGY STAR certified | not matched | yes |
| Refrigerant | not filed | R-134a, GWP 1430 |
| On the market since | not filed | 2024-12-13 |
What it costs to run
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.
- The actual warranty term is printed in each model’s documentation, not in any registry.
Which should you pick?
- Pick the ARISTON ARIHPWH-40 if running cost matters most: it uses 2,623 kWh less a year on the same test.
- Pick the AMERICAN PESX-40 1** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the ARISTON ARIHPWH-40.
- Neither if your household's busiest hour needs more than 66 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.
Each model on its own
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AMERICAN PESX-40 1**
Its filed figures, class position and running cost on your ZIP.
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ARISTON ARIHPWH-40
Its filed figures, class position and running cost on your ZIP.