Cooling Heat Load & AC Cost Estimator

1. Space Parameters

Default is 15 BTU/hr/Sq. Ft. (Use higher values for sunny/poorly insulated rooms).

1 W = 3.41 BTU/hr

2. People (Occupancy) Heat Load

3. Equipment Heat Load (Kitchen/Other Appliances)

4. AC Operating Cost Parameters

Cooling Heat Load Calculation Formulas

Total Heat Load Formula

Total Heat Load (BTU/hr) = Transmission + Lighting + Occupancy + Equipment

Component Calculations

1. Transmission/Infiltration Load

Transmission Load = Area (sq. ft.) × Wall Factor (BTU/hr/sq. ft.)
Typical Wall Factors: 10-30 BTU/hr/sq. ft. based on insulation and climate

2. Lighting Load

Total Lighting Watts = Area (sq. ft.) × Lighting Factor (Watts/sq. ft.)
Lighting Load = Total Lighting Watts × 3.412 (BTU/watt)

3. Occupancy Load

Occupancy Load = Number of People × Heat Output per Person (BTU/hr/person)
Typical Values: 400-600 BTU/hr per person (moderate activity)

4. Equipment Load

Equipment Load = Number of Units × Heat Output per Unit (BTU/hr/unit)
Commercial kitchen equipment typically ranges from 5,000-25,000 BTU/hr per unit

Air Conditioning Sizing

AC Capacity (Tons) = Total Heat Load (BTU/hr) ÷ 12,000 BTU per Ton
Recommended AC Capacity = Calculated Tons + 15-20% safety factor

Operating Cost Estimation

AC Power (kW) = (Total Heat Load ÷ EER) ÷ 1,000
Daily Cost = AC Power (kW) × Operating Hours × Cost per kWh
Annual Cost = Daily Cost × 365 days

Where EER (Energy Efficiency Ratio) = 10 (industry standard assumption)

Key Conversion Factors

  • 1 Ton of Cooling = 12,000 BTU/hour
  • 1 Watt = 3.412 BTU/hour (for electrical equipment)
  • Typical EER: 8-12 for commercial AC systems
  • Heat from People: 400-800 BTU/hr depending on activity level

Design Considerations for Commercial Kitchens

  • Kitchens typically require 25-50% more cooling than regular spaces
  • Ventilation makeup air significantly increases cooling load
  • Heat-producing equipment (ovens, fryers, steamers) are major contributors
  • Peak occupancy during meal service creates maximum load conditions
  • Consider zoning for kitchen vs. dining areas