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Commercial Tonnage Calculator

Commercial spaces carry far heavier internal loads: people (~600 BTU each), computers (~400 BTU each) and equipment. Server rooms are sized on equipment watts, not floor area.

Room

Estimate only — confirm with a professional load calculation.

Result
BTU/HR LOAD
Recommended unit
Tonnage equivalent

Where the commercial multiplier comes from

Commercial spaces carry loads homes don't: door-opening infiltration on customer traffic, display and task lighting running all day (every watt becomes heat), denser occupancy, and equipment from espresso machines to POS terminals — which is why this calculator applies a commercial uplift and asks about equipment separately. Two field practices worth copying: size at realistic peak occupancy (a Saturday afternoon, not a Tuesday morning — inverters idle through the quiet hours), and above roughly 5 tons prefer two units over one for redundancy and evener coverage. The dedicated pages for retail shops, restaurants, gyms and server rooms tune these factors per space — and for server rooms specifically, ignore square footage entirely and size on equipment watts.

FAQ

How do I size AC for a server room?

Size on the IT load, not the floor area: every watt of equipment power becomes ~3.41 BTU/hr of heat. A 5 kW rack needs ~17,000 BTU/hr (1.4 tons) of dedicated cooling plus redundancy.