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CoolLoad Pro – Free HVAC Cooling Load Calculator | ASHRAE Based
Project Information
Enter project identification and metadata
Room Geometry
Define room dimensions – derived values calculated automatically
Floor Area
—
m²
Ceiling Area
—
m²
Total Wall Area
—
m²
Room Volume
—
m³
Perimeter
—
m
Design Conditions
Outdoor and indoor design parameters
Building Construction
Wall, roof, floor types and thermal transmittance (U-values)
Net area minus windows. Leave blank to auto-calculate.
Windows / Glazing
Define each window group – conduction and solar gains calculated separately
SC=1.0 for single clear reference. Override as needed.
Occupancy
People heat gain – sensible and latent components per ASHRAE Handbook Fundamentals
People Sensible Load
—
W
People Latent Load
—
W
Total People Load
—
W
Lighting
Internal heat gain from lighting – Q = P × Usage Factor
1.0 = all heat to space. Fluorescent ballast factor ≈ 1.2
Fraction of lights ON at peak (0–1)
Lighting Heat Gain
—
W
Equivalent
—
BTU/hr
Equipment / Appliances
Internal heat gain from electrical equipment
Total Equipment Heat
—
W
Equivalent
—
BTU/hr
Ventilation (Fresh Air)
Outdoor air load per ASHRAE 62.1 – sensible and latent components
Ventilation Airflow
—
L/s
Vent. Sensible
—
W
Vent. Latent
—
W
Total Vent. Load
—
W
Infiltration
Uncontrolled air leakage through the building envelope
Typical: Tight 0.2, Average 0.5, Leaky 1.0
Infiltration Airflow
—
L/s
Inf. Sensible
—
W
Inf. Latent
—
W
Total Inf. Load
—
W
Cooling Load Summary
Complete breakdown of all heat gain components
—
W
Total Sensible
—
W
Total Latent
—
W
Grand Total
—
TR
Cooling Capacity
—
BTU/hr
BTU/hr
—
kW
kW Cooling
Load Distribution
Detailed Breakdown
| Load Component | Sensible (W) | Latent (W) | Total (W) | BTU/hr | % |
|---|
AC Unit Selection
Recommended equipment based on calculated cooling capacity
Required Capacity
—
TR
Installed Capacity
—
TR
Oversizing
—
%
Recommended Configuration
Calculation Details
Step-by-step engineering equations with substituted values
⚠ Engineering Assumptions & Disclaimers:
• SHGF values are configurable engineering defaults for summer peak conditions (approximately 32°N latitude). They are not reproduced from proprietary ASHRAE tables.
• CLF values are simplified approximations. For accurate analysis, use ASHRAE-published CLF tables for the specific building mass and hour of interest.
• Ventilation latent load uses a simplified psychrometric approximation for humidity ratio from RH and temperature.
• U-values are representative defaults for typical constructions. Always verify against actual construction specifications.
• This calculator is suitable for preliminary design and educational use. Final engineering designs must be validated with detailed load calculation software.
• SHGF values are configurable engineering defaults for summer peak conditions (approximately 32°N latitude). They are not reproduced from proprietary ASHRAE tables.
• CLF values are simplified approximations. For accurate analysis, use ASHRAE-published CLF tables for the specific building mass and hour of interest.
• Ventilation latent load uses a simplified psychrometric approximation for humidity ratio from RH and temperature.
• U-values are representative defaults for typical constructions. Always verify against actual construction specifications.
• This calculator is suitable for preliminary design and educational use. Final engineering designs must be validated with detailed load calculation software.
CoolLoad Pro is a free online HVAC cooling load calculator designed for mechanical and HVAC engineers. Built on ASHRAE Handbook of Fundamentals and CIBSE Guide A standards, this professional tool calculates the complete cooling load of any room or space — covering walls, roof, windows, occupancy, lighting, equipment, ventilation, and infiltration. Get instant results in Tons of Refrigeration (TR), kW, and BTU/hr — with a full step-by-step calculation breakdown and PDF export.
Q: What is the HVAC cooling load calculator used for?
A: It calculates the total heat gain of a room or building to determine the required air conditioning capacity in TR, kW, or BTU/hr.
Q: Is CoolLoad Pro free to use?
A: Yes, CoolLoad Pro is completely free — no login or registration required. ,
Q: Which standard does CoolLoad Pro follow?
A: CoolLoad Pro follows ASHRAE Handbook of Fundamentals and ASHRAE 62.1 for ventilation, along with CIBSE Guide A conventions for U-values.
Q: Can I export the cooling load report as PDF?
A: Yes, CoolLoad Pro includes a built-in PDF export and print function for professional reporting.
Q: Does CoolLoad Pro support SI and Imperial units?
A: Yes, the calculator supports both SI (metric) and Imperial unit systems.
Q: How accurate is this cooling load calculator?
A: CoolLoad Pro is suitable for preliminary engineering design. Final designs should be validated with detailed simulation software.
