Include evaporator fans, lights, people, vehicles, machines and heaters.
In short: use rated power and actual operating time instead of one generic table.
Fan duty depends on controls; do not assume 24-hour full load. Keep battery chargers outside unless designed for the cold room.
Typical heat outputs
| Source | Typical heat output |
|---|---|
| LED lighting | ~10 W per fixture |
| Evaporator fans | 50–200 W per motor |
| People (active work) | ~270 W per person |
| Electric forklift / pallet truck | 3–5 kW while operating |
Applying a duty fraction
Apply a realistic duty fraction — a forklift inside for 20 minutes an hour contributes about a third of its rated figure. People and lighting are usually present only during working shifts, so scale them to the hours the room is actually worked.
Don't forget the fans
Evaporator fan heat is unavoidable and runs whenever the unit does, so always include it at full value. In a lightly loaded chill room the fans alone can be a meaningful share of the internal load.
Related articles
- Heat Load Calculation: The Four Components
- Product load explained
- Transmission load explained
- From total load to design load
- Using the Frostbox size calculator
For a checked calculation, use the Frostbox size calculator or contact [email protected].
