Size a window or through-wall room AC using the ENERGY STAR area table and stated adjustments.
← All Home & Trade calculators
Saved records stay in this browser. Download a text result to keep a separate copy or move it to another device.
Size a window or through-wall room AC using the ENERGY STAR area table and stated adjustments.
Formula: ENERGY STAR table capacity × sun adjustment + 600 × occupants above two + 4,000 for a kitchen.
Table assumes an 8-foot ceiling. A room table is not a whole-house or multi-zone mini-split design. High ceilings, unusual glass and disconnected rooms need further evaluation.
A whole-house square-foot estimate is a starting scenario. Climate, insulation, air leakage, windows, solar exposure, people and duct location can materially change the actual cooling requirement. A large unit can cool the air before removing enough moisture.
Manual J calculates sensible and latent loads. Manual S selects equipment using performance data. Manual D designs the duct system using room airflow, the blower’s pressure capability and the losses of ducts, fittings and components. Velocity-only duct dimensions do not complete that design.
One ton of cooling equals 12,000 BTU per hour. Thermal cooling kW describes heat removed; electrical input kW describes power consumed. Room/window AC estimates use the ENERGY STAR room table separately from the whole-house scenarios.
For heat pumps, cooling results alone cannot select the system: heating output at winter design temperature and backup heat need a separate evaluation. Material calculators estimate quantities; they do not size structural members or establish electrical or plumbing code compliance.