What size furnace does my house actually need?

The only correct answer comes from a Manual J load calculation — a room-by-room analysis of square footage, insulation, windows, air leakage, and orientation. Square-footage rules of thumb produce oversized systems in most Chicagoland homes.

Why Oversizing Is the Most Expensive Mistake

An oversized furnace short cycles, heats unevenly, wears out faster, and costs more up front and every month after. A properly sized system runs longer, gentler cycles that hold temperature evenly. Any quality quote should include a load calculation — if a contractor sizes by eyeball, get another quote.

Your Local Air Quality and HVAC Experts

All Set HVAC serves Arlington Heights and the Chicago Northwest Suburbs as the local expert in air quality testing, HVAC maintenance plans, and new heating and cooling installations. We find the cause instead of chasing symptoms, and we stand behind every job with the All Set Guarantee. Schedule your $99 Air Score Test at (847) 807-6100 today.