Cooling load calculator
Calculate HVAC tonnage and required airflow
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The Cooling Load Calculator helps HVAC engineers and contractors estimate air conditioning requirements for buildings. Calculate cooling load in tons and determine required airflow (CFM) based on space area, occupancy, and space type.
Proper cooling load calculation ensures HVAC systems are correctly sized to maintain comfort while avoiding energy waste from oversized equipment. The calculator uses simplified load factors based on space type and occupancy to provide quick estimates.
Enter floor area, occupant count, and space type to calculate sensible load, occupant load, total cooling load in tons, and required airflow in CFM. The tool helps size HVAC equipment and ductwork for offices, retail, restaurants, residential, and data center applications.
Features
Everything you need
- Cooling load calculation in tons
- Required airflow (CFM) determination
- Space type load factors
- Sensible and occupant load breakdown
- Multiple occupancy type support
- Simplified load estimation
- Imperial and metric units
How it works
Simple workflow
- 1Enter floor area and occupant count
- 2Select space type (office, retail, restaurant, etc.)
- 3Review calculated sensible and occupant loads
- 4See total cooling load in tons
- 5View required airflow in CFM
Use cases
Built for real-world scenarios
HVAC system sizing
Estimate cooling requirements for new HVAC installations and equipment selection.
Quick load estimates
Get rapid cooling load estimates during preliminary design before detailed calculations.
Equipment selection
Determine appropriate air conditioning unit sizes and capacities for different spaces.
Energy planning
Estimate cooling energy requirements for building energy analysis and utility planning.
FAQ
Frequently asked questions
Cooling Load = (Area × Load Factor) + (Occupants × Occupant Load Factor). Load factors vary by space type: Offices ~30 BTU/hr per SF, Retail ~35, Restaurants ~50. Convert to tons: Tons = BTU/hr ÷ 12,000.
One ton of cooling = 12,000 BTU/hr, equivalent to the heat removal capacity of melting one ton of ice in 24 hours. Residential systems are typically 1-5 tons, commercial 5-50+ tons.
CFM ≈ Cooling Load (BTU/hr) ÷ 30 for typical applications. More precisely: CFM = Sensible Load ÷ (1.08 × ΔT), where ΔT is temperature difference. The calculator provides simplified estimates.
Solar gain (windows, orientation), internal loads (lights, equipment, people), building envelope (insulation, air leakage), and outdoor conditions (temperature, humidity). This calculator uses simplified factors.
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We're always looking to improve our calculators. If you have ideas for new features, improvements, or found something that could work better, we'd love to hear from you.
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