AMERICAN ENS-40W 1** vs Stiebel Eltron Accelera 220 E: which uses less energy?
At the low draw pattern the Stiebel Eltron Accelera 220 E uses 799 kWh a year and the AMERICAN ENS-40W 1** 2,550 — 1,752 kWh (69%) less, about 17,516 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 low draw pattern.
| Figure | AMERICAN ENS-40W 1** | Stiebel Eltron Accelera 220 E |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.88 | 2.81 (better) |
| Energy use per year (kWh) | 2,550 | 799 (better) |
| First hour rating (gal) | 41 | 41 |
| Rated storage volume (gal) | 37 | 58 |
| Installed cost range | not published | not published |
| ENERGY STAR certified | not matched | not matched |
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 Stiebel Eltron Accelera 220 E if running cost matters most: it uses 1,752 kWh less a year on the same test.
- Pick the AMERICAN ENS-40W 1** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Stiebel Eltron Accelera 220 E.
- Neither if your household's busiest hour needs more than 41 gallons of hot water — neither lists more.
Each model on its own
-
AMERICAN ENS-40W 1**
Its filed figures, class position and running cost on your ZIP.
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Stiebel Eltron Accelera 220 E
Its filed figures, class position and running cost on your ZIP.