Table 1 Assumptions for three system and envelop efficiency levels.
Efficiency Level | Low | Standard (ASHRAE 90.1–2013) | High |
|---|---|---|---|
COP of AHU | 1.8 | 2.4 | 3 |
water heater thermal efficiency | 46.7% | 62.3% | 77.9% |
gas burner efficiency | 48.0% | 64.0% | 80.0% |
VAV reheat coil efficiency | 60.0% | 80.0% | 95.0% |
fan total efficiency | 36.3% | 48.4% | 60.5% |
pump motor efficiency | 18.0% | 24.0% | 30.0% |
envelope thermal resistance | 0.75 standard level | varies by climate | 1.25 standard level |
