Both are 74-gallon heat pump water heaters. The NWP500S080AUMB is more efficient (UEF 4.05 vs 3.48). The NWP500S080AUMB saves $27/year to operate. All figures from published specs and EIA energy prices.
Performance
| Spec | NWP500S080AUMB Navien · Heat Pump | NHP80 Noritz · Heat Pump |
|---|---|---|
| UEF | 4.05Difference: 0.57 | 3.48 |
| Capacity | 74 galidentical | |
| First Hour Rating | 85 gal | 86 galDifference: 1 gal |
| kW Input | 5 kW | 4.50 kWDifference: 0.50 kW |
The NWP500S080AUMB leads on efficiency. But does it fit? Sizing guide
Physical dimensions
| Dimension | NWP500S080AUMB | NHP80 |
|---|---|---|
| Height | 71.60"Difference: 2.40" | 74" |
| Width | 25"Difference: 3" | 28" |
| Depth | 25"Difference: 3" | 28" |
| Weight | 220 lbs | — |
The NHP80 is taller. Fit checked. Now the operating cost.
Operating cost
| Cost | NWP500S080AUMB | NHP80 |
|---|---|---|
| Annual Operating Cost | $218/yrDifference: $27/yr | $245/yr |
| 10-Year Operating Cost | $2,180Difference: $270 | $2,450 |
| Annual Energy | 1,265 kWhDifference: 159 kWh | 1,424 kWh |
10-year difference: $270 in favor of the NWP500S080AUMB, at current US average energy rates. Actual savings depend on local rates and usage patterns.
Costs vary by state. The NWP500S080AUMB ranges from $139/yr (ND) to $526/yr (HI). The NHP80 ranges from $157/yr (ND) to $593/yr (HI).
$27/yr separates them. Install requirements determine the upfront gap. Installation accessories
Installation requirements
| Requirement | NWP500S080AUMB | NHP80 |
|---|---|---|
| Voltage | 240Videntical | |
| Amperage | 23Aidentical | |
| Breaker | 30Aidentical | |
| Condensate Drain | Yesidentical | |
Same electrical requirements. Swapping between these units should not require electrical changes.
Warranty
| Coverage | NWP500S080AUMB | NHP80 |
|---|---|---|
| Tank | 10 yridentical | |
| Parts | 10 yridentical | |
| Labor | 1 yridentical | |
Features
| Feature | NWP500S080AUMB | NHP80 |
|---|---|---|
| Wi-Fi / Smart | Yes | No |
| Noise Level | 45 dBDifference: 9 dB | 54 dB |
| Refrigerant | R-134aidentical | |
Decision split
Pick this one if...
Navien NWP500S080AUMB
- Your ceiling or space is under 74"
- Minimizing energy cost matters (saves $27/yr)
- You need quiet operation (45 dB vs 54 dB)
- You want smart home / Wi-Fi control
Neither if...
- You have no floor drain and cannot add condensate handling
- 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