Cooling Load Calculator - Free Online Tool

Our Cooling Load Calculator provides a systematic approach to determining the total heat gain that your HVAC system must manage. It doesn't just guess; it breaks down complex thermal physics into manageable inputs.

You will input key parameters such as building dimensions (square footage), window size, orientation, and occupancy levels. The tool then calculates loads from various sources:

• Conduction Load: Heat transfer through walls and roof (based on R-values).
• Solar Load: Heat entering through windows and skylights.
• Internal Gains: Heat generated by people (occupants) and equipment (lighting, computers).

By summing these calculated loads—for example, determining if a 2,500 sq ft office needs 30,000 BTU/h or 45,000 BTU/h—you receive an accurate required cooling capacity.

To ensure the most accurate cooling load calculation, think like an engineer and gather precise data. The quality of your input directly determines the reliability of the output.

Before running the analysis, collect:

• Window U-Values: Knowing the actual heat transfer coefficient (U-value) of your glass is more precise than just using window size.
• Occupancy Density: Instead of guessing, estimate peak occupancy (e.g., 5 people per 1,000 sq ft) and the heat output per person (approx. 23 BTU/h).
• Design Conditions: Use the expected peak outdoor conditions for your location (e.g., 95°F dry bulb temperature), not just average weather.

If you are designing a mixed-use space, calculate loads for each zone separately rather than aggregating them into one large number to ensure localized comfort.