Basic Heating & Cooling Load

Detailed Calculation Methodology

The standard thermodynamic equations for Sensible Air Load and Water Load rely on the mass flow rate, specific heat capacity (C_p), and the absolute temperature difference between entering and leaving conditions. To maintain strict precision, this tool calculates fluid density dynamically based on the average operating temperature.

Air Side Equations

• Q_air = Total Sensible Load (kW)
• V = Volumetric Air Flow Rate (L/s)
• C_p(air) = Specific Heat Capacity of Air = 1.006 kJ/kg·K
• ρ_air = Density of Air (kg/m³), calculated dynamically via the Ideal Gas Law at Standard Atmospheric Pressure (101.325 kPa):
  ρ_air = 101325 / [ 287.05 × (T_avg + 273.15) ]

Water Side Equations

• Q_water = Total Heat Transfer (kW)
• V = Volumetric Water Flow Rate (L/s)
• C_p(water) = Specific Heat Capacity of Water = 4.18 kJ/kg·K
• ρ_water = Density of Water (kg/m³). While often assumed as 1000 kg/m³, this tool utilizes a polynomial curve to adjust density precisely based on the average fluid temperature.

Cooling Load Check Figures

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