Navien NFB700-500CvsViessmann CI2-500
Side-by-side commercial boiler comparison
Navien NFB700-500C
Thermal Efficiency
97.5%
Input Rate
499MBTU/hr
Turndown Ratio
12.00
Application
Indoor
Viessmann CI2-500
Thermal Efficiency
97.9%
Input Rate
500MBTU/hr
Turndown Ratio
10.00
Application
Indoor
Key differences
Both models are closely matched on thermal eff: 97.5 vs 97.9 %. The Viessmann CI2-500 is larger at 500 MBTU/hr versus 499 MBTU/hr.
Performance
| Spec | Navien | Viessmann |
|---|---|---|
| Thermal Efficiency(%) | 97.5 | 97.9 |
| Full-Load Input Rate(MBTU/hr) | 499 | 500 |
| Turndown Ratio | 12.00 | 10.00 |
Configuration
| Spec | Navien | Viessmann |
|---|---|---|
| Application | Indoor | Indoor |
| Control Type | Multi-stage | Multi-stage |
| Model Name | NFB700-500C | CI2-500 |