Calculate the total Sensible and Latent heat gain (BTU/hr) for commercial kitchen spaces to properly size HVAC cooling and dehumidification equipment. Commercial kitchens have unique heat loads from cooking equipment, occupancy, ventilation, and lighting.
How It Works
Heat Load Components:
1. Appliance Load: ~20% of total gas appliance input BTU/hr becomes sensible heat gain in the space.
2. Occupancy Load: Each person adds 250 BTU/hr sensible + 200 BTU/hr latent heat (400-450 BTU/hr total per person).
3. Ventilation (MUA) Load:
- Sensible: CFM × 1.08 × ΔT (temperature difference between MUA and indoor)
- Latent: CFM × 0.68 × ΔGrains (moisture difference)
4. Lighting Load: 1 W/sqft × 3.41 BTU/hr/watt
Total Cooling (Tons):
Total BTU/hr = Sensible + Latent
Tons of Refrigeration (TR) = Total BTU/hr / 12,000Heat Load Components:
1. Appliance Load: ~20% of total gas appliance input BTU/hr becomes sensible heat gain in the space.
2. Occupancy Load: Each person adds 250 BTU/hr sensible + 200 BTU/hr latent heat (400-450 BTU/hr total per person).
3. Ventilation (MUA) Load:
- Sensible: CFM × 1.08 × ΔT (temperature difference between MUA and indoor)
- Latent: CFM × 0.68 × ΔGrains (moisture difference)
4. Lighting Load: 1 W/sqft × 3.41 BTU/hr/watt
Total Cooling (Tons):
Total BTU/hr = Sensible + Latent
Tons of Refrigeration (TR) = Total BTU/hr / 12,000FAQ
Q: What is the difference between sensible and latent heat?
A: Sensible heat affects temperature (dry bulb). Latent heat involves moisture/humidity. Both must be accounted for in HVAC sizing.
Q: How many tons of cooling do I need for my kitchen?
A: Commercial kitchens typically need 1 ton per 300-400 sq ft, but this varies significantly based on equipment load.
Q: What is a safe safety factor to add?
A: Add 10-20% to the calculated cooling capacity for safety margin.
References
- ASHRAE Handbook — Fundamentals (Chapter 18: Nonresidential Cooling and Heating Load)
- ASHRAE Handbook — HVAC Applications (Chapter 31: Commercial Kitchen Ventilation)
- ACCA Manual J: Residential Load Calculation (adapted methodology)
- SMACNA: Commercial Kitchen Ventilation Design