Navien NWP500 40-Gallon vs Ruud Heat Pump 65-Gallon (PROUH65 T0 RU120-M)

The Navien NWP500 40-Gallon is the more efficient unit: UEF 3.85 versus 3.33 — about 14% less energy for the same hot water. At national average rates that works out to about $143/year for the Navien NWP500 40-Gallon against $165/year for the Ruud Heat Pump 65-Gallon (PROUH65 T0 RU120-M) — a $22 annual difference. The Navien NWP500 40-Gallon delivers more hot water in the peak hour (65 gal first-hour rating vs 63 gal). Installation differs: the Ruud Heat Pump 65-Gallon (PROUH65 T0 RU120-M) runs on a 120 V circuit (often no new wiring), while the other needs a dedicated 240 V circuit.

Navien NWP500 40-Gallon Ruud Heat Pump 65-Gallon (PROUH65 T0 RU120-M)
Uniform Energy Factor (UEF) 3.85 3.33
Fuel Electric Electric
First-hour rating 65 gal 63 gal
Rated storage volume 44 gal 59 gal
Draw pattern Medium Medium
Annual electricity use 840 kWh/yr 971 kWh/yr
Heat pump type 240 Volt Integrated HPWH 120 Volt Integrated HPWH
Input voltage 240 120
Max current draw 23 A 12 A
Recovery efficiency 461 % 398 %
Smart / connected capable No No
Refrigerant (GWP) R-134a (GWP:1430) R-134a (GWP:1430)
Compressor low-temp cutoff 41 °F 37 °F
Height 63 in 64.2 in
Diameter 21.8 in 24.3 in
ENERGY STAR certified Yes Yes

Frequently asked questions

Which costs less to run, the Navien NWP500 40-Gallon or the Ruud Heat Pump 65-Gallon (PROUH65 T0 RU120-M)?

The Navien NWP500 40-Gallon: about $143/year versus $165/year for the Ruud Heat Pump 65-Gallon (PROUH65 T0 RU120-M) at national average rates — a $22 annual difference.

Are the Navien NWP500 40-Gallon and Ruud Heat Pump 65-Gallon (PROUH65 T0 RU120-M) both ENERGY STAR certified?

Yes — every water heater in this database is drawn from the U.S. EPA ENERGY STAR certified water heater datasets.