Basic Heating & Cooling Load
Fill in any combinations of known values. The calculator will automatically solve for the remaining unknown variables using dynamically calculated air and water properties.
Air Side Calculation
kW
L/s
Temperature Conditions
°C
°C
K
Awaiting inputs...
Water Side Calculation
kW
L/s
Temperature Conditions
°C
°C
K
Awaiting inputs...
Calculation Methodology
The basic heating and cooling load formulas depend on the mass flow rate and the specific heat capacity of the fluid medium. Because air and water density ($ \rho $) and specific heat capacity ($ C_p $) fluctuate with temperature, this tool calculates them dynamically.
The Core Formula
Q (kW) = [ V (L/s) / 1000 ] × ρ (kg/m³) × Cp (kJ/kg·K) × ΔT (K)
- If Entering and Leaving temperatures are provided, the tool calculates the exact average temperature of the fluid to derive precise properties.
- If only ΔT is provided, the tool assumes standard HVAC design conditions (Air at 20°C, Water at 10°C) for a rapid, mostly-accurate preliminary estimate.
| Occupancy (air conditioned area) | Cooling Load W/m² |
|---|---|
| Apartments, residence (un-insulated, poorly sealed and west facing) | 200 |
| Apartments, residence (insulated, well-sealed and not facing west) | 120 |
| Auditorium | 280 |
| Banks | 175 |
| Hairdresser | 215 |
| Beauty Shop | 260 |
| Cafeteria | 350 |
| Classroom | 95 |
| Clinic | 190 |
| Clothing Store | 165 |
| Computer Room | 480 |
| Conference Room | 275 |
| Department Store: Basement | 125 |
| Department Store: Main Floor | 150 |
| Department Store: Upper Floors | 125 |
| Factory – Light Manufacture | 275 |
| Factory – Heavy Manufacture | 490 |
| Food Stores | 160 |
| Hotel & Motel Rooms | 120 |
| Laboratory | 130 |
| Library | 150 |
| Mall | 135 |
| Medical Offices | 185 |
| Milk Bars, Fast Food | 270 |
| Office – General (Perimeter) | 170 |
| Office – General (Interior) | 100 |
| Office – Private | 180 |
| Post Office | 180 |
| Restaurants | 330 |
| Shoe Store | 185 |
| Supermarket | 160 |
| Theatre | 280 |
Reference : AIRAH Technical Handbook