Frequently Asked Questions
What size AC do I need for my home?+
AC size depends on square footage, insulation quality, climate zone, ceiling height, and sun exposure. This calculator gives a simplified BTU range to help you estimate tonnage before getting a professional load calculation.
How many BTUs per square foot do I need?+
A common rule of thumb is 20–25 BTU per square foot for cooling. This tool starts at 25 BTU/sqft and adjusts for insulation, climate, and ceiling height.
Why does insulation and sun exposure matter for HVAC sizing?+
Poor insulation or heavy sun exposure increases heat gain, which raises the BTU load. Better insulation and shaded exposure lower the cooling load and can reduce required tonnage.
Should I round up HVAC tonnage?+
It's typically safer to round up to the nearest 0.5 ton to avoid undersizing, but final selection should be confirmed by a licensed HVAC professional using a full Manual J calculation.