DoesTheMath

A. O. SMITH ENJB-30 1** vs Ruud PROE28 S2 RH93 SB: which uses less energy?

At the low draw pattern the Ruud PROE28 S2 RH93 SB uses 2,439 kWh a year and the A. O. SMITH ENJB-30 1** 2,494 — 54 kWh (2%) less, about 542 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.

Filed and computed figures
A. O. SMITH ENJB-30 1** Ruud PROE28 S2 RH93 SB
UEF (Uniform Energy Factor) 0.9 0.92 (better)
Energy use per year (kWh) 2,494 2,439 (better)
First hour rating (gal) 47 48
Rated storage volume (gal) 26 26
Installed cost range not published not published
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

A. O. SMITH ENJB-30 1**: 2,494 kWh a year Ruud PROE28 S2 RH93 SB: 2,439 kWh a year

A. O. SMITH ENJB-30 1** — 2,494 kWh a year Ruud PROE28 S2 RH93 SB — 2,439 kWh a year

Ruud PROE28 S2 RH93 SB is 55 kWh a year lower than A. O. SMITH ENJB-30 1**.

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.
  • The actual warranty term is printed in each model’s documentation, not in any registry.

Which should you pick?

  • Pick the Ruud PROE28 S2 RH93 SB if running cost matters most: it uses 54 kWh less a year on the same test.
  • Pick the A. O. SMITH ENJB-30 1** if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Ruud PROE28 S2 RH93 SB.
  • Neither if your household's busiest hour needs more than 48 gallons of hot water — neither lists more. Check whether a 30-gallon heater is enough.

Each model on its own

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