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

1
Enter floor area and occupant count
2
Select space type (office, retail, restaurant, etc.)
3
Review calculated sensible and occupant loads
4
See total cooling load in tons
5
View 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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