BTU (British Thermal Unit) ... AIR CONDITIONING SIZING CHART ; 100 to 150 sq ft. 5,000 BTUs. 150 to 250 sq ft. 6,000 BTUs. 250 to 300 sq ft. 7,000 BTUs. 300 to 350 sq ft. 8,000 BTUs.

It's critical to get the right size when buying a window air conditioner. Consumer Reports explains how to do it. Plus, the best small, midsized, and large window AC units.

In our example, T m is 192°F; T a is 70°F, and âT is 122°F and watts required are 120 or 410 Btu/hr. Specific heat of air, C p, varies from 0.2936 Btu/lb-°F at 40°F to .2403 Btu/lb-°F at ...