What Size AC Unit Do I Need?

AC systems are sized in tons (1 ton = 12,000 BTU/hr of cooling). Most central Illinois homes need 2.5-5 tons. A rough estimate is 1 ton per 500-600 square feet, but the only accurate method is a Manual J load calculation that accounts for insulation, windows, sun exposure, and layout. Here's how to figure out what your home actually needs.

An oversized AC cools too fast, shuts off before removing humidity, and short-cycles - making your home feel clammy and uncomfortable while wearing out the compressor. An undersized AC runs all day, can't keep up during heat waves, and drives your electric bill through the roof. Central Illinois humidity makes correct sizing even more critical - your AC needs to run long enough each cycle to pull moisture out of the air.

• 1,000-1,200 sq ft: 2-2.5 tons
• 1,200-1,500 sq ft: 2.5-3 tons
• 1,500-2,000 sq ft: 3-3.5 tons
• 2,000-2,500 sq ft: 3.5-4.5 tons
• 2,500-3,000 sq ft: 4.5-5 tons

These are ballpark numbers. Homes with poor insulation, lots of west-facing windows, or finished attics may need more capacity. Ready to compare prices? Check our new AC cost guide.

A Manual J load calculation factors in square footage, insulation R-value, window size and orientation, number of occupants, ceiling height, ductwork condition, and local climate data. Any installer who sizes your AC based on your old unit's size or a quick square footage guess is cutting corners. That shortcut costs you in comfort and energy bills for the next 10-15 years.

We do a proper load calculation on every installation. We size your system for your home - not for a bigger sale. AC installation available across Peoria, Pekin, Morton, Washington, Canton, and surrounding areas. To keep your home trouble-free, call (309) 347-5309 or schedule a free estimate.