Room volume ft³ X Product volume displacement factor X ACH X 0.018 X (To - Ti) = Btu/hr Sensible heat.
Product volume displacement factor is a function of the amount of total air space displaced by items stored in the room. Calculated automatically by algorithm. Typically from 0.25 to 0.75 depending upon room size (volume) and aspect ratios comparing internal length, width and height dimensions.
ACH is Air Changes per Hour
0.018 is a constant
To is Ambient DB °F
Ti is Room Temperature DB °F
Product volume displacement factor may be overruled (factor 1.0) if desired, for purposes of calculating Freezer puul down gains in empty rooms for example, by application of a Special Features Code.