How room-size recommendations work
Manufacturer room-size ratings assume a typical room: about 8-foot ceilings, average insulation, moderate sun and one or two occupants. Real rooms differ, which is why the tool above adjusts for ceiling height, sun exposure, insulation, occupancy and appliances.
Reading the results
Use the suggested SACC (DOE) range as a starting band, then compare the products in that band on noise, dehumidification, window-kit fit and features. When your adjusted area lands between two sizes, choosing the larger unit is usually better in humid climates (more dehumidification headroom) while the smaller unit is often fine in dry, shaded rooms.
Estimates, not guarantees
This tool provides general guidance only. It is not professional HVAC engineering advice, and actual performance depends on your specific room, installation quality, and climate. For complex spaces — open-plan areas, sunrooms, converted garages — consider consulting an HVAC professional.