Building Envelope
Foundation Type: Affects heat loss/gain patterns. Basements naturally cooler; slabs exposed at edges; crawlspaces variable.
Perimeter (Slab): Edge length where most slab heat loss occurs. Insulation significantly reduces this loss.
Square Footage: Total conditioned area, all floors. Primary driver of heating/cooling load.
Construction Type: Frame homes respond quickly to temperature changes; CBS (concrete block) has higher thermal mass.
Home Type: Mobile homes have tighter ducts (higher static pressure) and higher infiltration at marriage lines.