Both are heat pump water heaters. The NWP500S050AUMB is more efficient (UEF 3.85 vs 3.44). The NWP500S050AUMB saves $18/year to operate. All figures from published specs and EIA energy prices.
Performance
| Spec | RE2H50S Bradford White · Heat Pump | NWP500S050AUMB Navien · Heat Pump |
|---|---|---|
| UEF | 3.44 | 3.85Difference: 0.41 |
| Capacity | 45 galDifference: 1 gal | 44 gal |
| First Hour Rating | 65 galidentical | |
| kW Input | 4.50 kWDifference: 0.50 kW | 5 kW |
The NWP500S050AUMB leads on efficiency. But does it fit? Sizing guide
Physical dimensions
| Dimension | RE2H50S | NWP500S050AUMB |
|---|---|---|
| Height | 59.19"Difference: 3.81" | 63" |
| Width | 21.75" | 21.70"Difference: 0.05" |
| Depth | 21.75" | 21.70"Difference: 0.05" |
| Weight | — | 181 lbs |
The NWP500S050AUMB is taller. Fit checked. Now the operating cost.
Operating cost
| Cost | RE2H50S | NWP500S050AUMB |
|---|---|---|
| Annual Operating Cost | $163/yr | $145/yrDifference: $18/yr |
| 10-Year Operating Cost | $1,630 | $1,450Difference: $180 |
| Annual Energy | 944 kWh | 840 kWhDifference: 104 kWh |
10-year modeled difference is $180. At this scale, local energy rates, usage patterns, and install costs matter more than the efficiency delta.
Costs vary by state. The RE2H50S ranges from $104/yr (ND) to $393/yr (HI). The NWP500S050AUMB ranges from $93/yr (ND) to $350/yr (HI).
$18/yr separates them. Install requirements determine the upfront gap. Installation accessories
Installation requirements
| Requirement | RE2H50S | NWP500S050AUMB |
|---|---|---|
| Voltage | 240Videntical | |
| Amperage | 19ADifference: 4A | 23A |
| Breaker | 30Aidentical | |
| Condensate Drain | — | Yes |
Same electrical requirements. Swapping between these units should not require electrical changes.
Warranty
| Coverage | RE2H50S | NWP500S050AUMB |
|---|---|---|
| Tank | 10 yridentical | |
| Parts | — | 10 yr |
| Labor | — | 1 yr |
Features
| Feature | RE2H50S | NWP500S050AUMB |
|---|---|---|
| Wi-Fi / Smart | — | Yes |
| Noise Level | — | 45 dB |
| Refrigerant | R-134aidentical | |
Decision split
Pick this one if...
Bradford White RE2H50S
- Your ceiling or space is under 63"
Pick this one if...
Navien NWP500S050AUMB
- Minimizing energy cost matters (saves $18/yr)
- You want smart home / Wi-Fi control
- Peak efficiency is the priority (UEF 3.85)
Neither if...
- Your home only has 120V service and you cannot upgrade the panel
- Your install space is under 700 sq ft of open air
Common accessories for this type of installation.
Common install considerations for heat pump units
What is required depends on your existing installation, local code, and installer preference.
As an Amazon Associate I earn from qualifying purchases. RatingPlate may earn a commission when you use qualifying Amazon links. Links to Amazon are marked "(paid link)". We never display prices because Amazon prohibits showing prices outside their platform.
Related
Sources. ENERGY STAR, manufacturer spec sheets, EIA average energy prices.Methodology