Room Air Conditioner BTU & Tonnage Sizing Calculator (ASHRAE Standard)
Calculate the ideal room air conditioner cooling capacity in British Thermal Units (BTU/hr), Refrigeration Tonnage (TR), and Horsepower based on floor dimensions, sun exposure, and occupancy.
Calculator Inputs
Live Real-TimeRequired AC Capacity (BTU/hr)
Tonnage Capacity (Tons TR)
1.33 Tons
Approximate Horsepower (HP)
2 HP
Total Room Area (m²)
20 m²
Standard Sizing: An 18,000 BTU (1.5 Ton / 2.25 HP) unit is ideal for covering this space comfortably and efficiently.
AC Sizing Breakdown
Detailed Calculation Breakdown
Calculation Methodology
Room Area = Length * Width. Base BTU = Area * (600 for temperate / 800 for hot sunny climates) + 600 BTU per extra occupant. Cooling Tons = Total BTU / 12,000. Horsepower = Total BTU / 8,000.
Important Legal & Educational Disclaimer
This HVAC engineering tool provides residential cooling load estimates based on standard heat gain principles.
This calculator is designed for educational and informational purposes only based on public statutory frameworks. The outputs do not constitute binding financial, tax, or legal advice. We assume no liability for decisions made based on these estimations. Always verify with the relevant official authorities or a certified professional advisor.
Frequently Asked Questions
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