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How to Calculate the Right AC Size in BTUs
Formula
A general rule is 20 BTU per square foot, adjusted for ceiling height, sun exposure, and occupants.
An undersized AC struggles to cool; an oversized unit cycles too frequently and wastes energy.
Common use cases:
- Size a window or portable AC unit
- Determine central AC tonnage
- Compare AC units when shopping
Frequently Asked Questions
Sarah Chen
Financial Analyst, CFA
Sarah is a Chartered Financial Analyst with over 8 years of experience in investment management and financial modeling. She specializes in retirement planning and compound interest calculations.
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