Both are heat pump water heaters. The HPTA-80-2 is more efficient (UEF 3.88 vs 3.38). The HPTA-80-2 saves $33/year to operate. All figures from published specs and EIA energy prices.
Performance
| Spec | HPTA-80-2 A. O. Smith · Heat Pump | NHP120 Noritz · Heat Pump |
|---|---|---|
| UEF | 3.88Difference: 0.50 | 3.38 |
| Capacity | 81 gal | 109 galDifference: 28 gal |
| First Hour Rating | 95 gal | 105 galDifference: 10 gal |
| kW Input | 4.50 kWidentical | |
The HPTA-80-2 leads on efficiency. But does it fit? Sizing guide
Physical dimensions
| Dimension | HPTA-80-2 | NHP120 |
|---|---|---|
| Height | 69"Difference: 15.50" | 84.50" |
| Width | 27"Difference: 3" | 30" |
| Weight | 302 lbs | — |
The NHP120 is taller. Fit checked. Now the operating cost.
Operating cost
| Cost | HPTA-80-2 | NHP120 |
|---|---|---|
| Annual Operating Cost | $220/yrDifference: $33/yr | $253/yr |
| 10-Year Operating Cost | $2,200Difference: $330 | $2,530 |
| Annual Energy | 1,279 kWhDifference: 188 kWh | 1,467 kWh |
10-year difference: $330 in favor of the HPTA-80-2, at current US average energy rates. Actual savings depend on local rates and usage patterns.
Costs vary by state. The HPTA-80-2 ranges from $141/yr (ND) to $532/yr (HI). The NHP120 ranges from $162/yr (ND) to $611/yr (HI).
$33/yr separates them. Install requirements determine the upfront gap. Installation accessories
Installation requirements
| Requirement | HPTA-80-2 | NHP120 |
|---|---|---|
| Voltage | 240Videntical | |
| Amperage | 22ADifference: 1A | 23A |
| Breaker | 30A | — |
Same electrical requirements. Swapping between these units should not require electrical changes.
Warranty
| Coverage | HPTA-80-2 | NHP120 |
|---|---|---|
| Tank | 10 yridentical | |
| Parts | — | 10 yr |
| Labor | — | 1 yr |
Features
| Feature | HPTA-80-2 | NHP120 |
|---|---|---|
| Refrigerant | R-134aidentical | |
Decision split
Pick this one if...
A. O. Smith HPTA-80-2
- Your ceiling or space is under 84.50"
- Minimizing energy cost matters (saves $33/yr)
- Peak efficiency is the priority (UEF 3.88)
Pick this one if...
Noritz NHP120
- You have high peak demand (105 gal FHR)
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.
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Related
Sources. ENERGY STAR, manufacturer spec sheets, EIA average energy prices.Methodology