"N1102.2.1.1. Unvented attic and unvented enclosed rafter assemblies. Unvented attic and unvented enclosed rafter assemblies conforming to Section R806.5 shall be provided with an R-value of R-22 (maximum U-Factor of 0.045) in Climate Zone 3-B or an R-value of R-26 (maximum U-factor of 0.038) in Climate Zones 5-B and 6-B shall be permitted provided all the following conditions are met:
Exception: Where an air handler that is integral to tested and listed HVAC equipment is used to provide whole-house mechanical ventilation, the air handler shall be powered by an electronically commutated motor."
"TABLE N1103.6.2 (R403.6.2)",
MECHANICAL VENTILATION SYSTEM FAN EFFICACY
FAN LOCATION | AIR FLOW RATE MINIMUM (CFM) | MINIMUM EFFICACY (CFM/WATT) | AIR FLOW RATE MAXIMUM (CFM) |
HRV or ERV | Any | 1.2cfm/watt | Any |
Range hoods | Any | 2.8 cfm/watt | Any |
In-line fan | Any | 2.8 cfm/watt | Any |
Bathroom, utility room | 10 | 1.4 cfm/watt | [LESS THAN]90 |
Bathroom, utility room | 90 | 2.8 cfm/watt | Any" |
Utah Code § 15A-3-203