304.5.2 Known air-infiltration-rate method.
FGC § 304.5.2
Where the air infiltration rate of a structure is known, the minimum required volume shall be determined as follows: For appliances other than fan-assisted, calculate volume using Equation 3-1. (Equation 3-1} For fan-assisted appliances, calculate volume using Equation 3-2. (Equation 3-2) where: Iother = All appliances other than fan assisted (input in Btu/h). I fan = Fan-assisted appliance (input in Btu/h). ACH = Air change per hour (percent of volume of space exchanged per hour, expressed as a decimal). For purposes of this calculation, an infiltration rate greater than 0.60 ACH shall not be used in Equations 3-1 and 3-2.













