Home & Construction
HVAC Cooling Load Calculator
Estimate base sensible load, design cooling capacity in kW, refrigeration tons, and BTU/h. The load-house visual assigns each entered heat source to the total before margin.
Required design cooling capacity (kW)-
Equivalent refrigeration tons-
Equivalent capacity (BTU/h)-
Base sensible load before margin-
Decision view
Building cooling-load composition
Building cooling-load compositionEnvelope, occupant, and equipment heat gains are assembled before one documented design margin is applied.
Exact scenario comparisonEnvelope and solar load allowance (W/m2) changes while all other entered assumptions remain constant.
| Envelope and solar load allowance (W/m2) | Required design cooling capacity (kW) | Equivalent refrigeration tons | Equivalent capacity (BTU/h) | Base sensible load before margin |
|---|
How to use HVAC Cooling Load Calculator
- Measure conditioned area and choose a climate- and envelope-specific allowance.
- Add design occupancy plus lighting and equipment gains.
- Use the result only as a screening value before a room-by-room sensible and latent load calculation.
Calculator guide
Understanding HVAC Cooling Load Calculator
Cooling capacity should be based on heat entering and generated inside the building, not floor area alone. This preliminary model combines envelope allowance, people, equipment, and design margin before converting capacity units.
Calculation method
How the calculation works
Estimate sensible envelope, occupant, lighting, and equipment loads, then apply the entered design margin and convert capacity units. Multiply conditioned area by the entered W/m² allowance, add occupant sensible gains and equipment kW, then apply the design margin and convert kW to tons and BTU/h.
Sizing discipline
Why bigger equipment can perform worse
Peak capacity does not describe humidity control or part-load operation.
Worked situations
Practical examples
- 180 m² at 95 W/m² contributes 17.1 kW.
- Four occupants at 120 W plus 2.5 kW equipment raise the base to about 20.08 kW.
- A 15% margin produces about 23.09 kW, or 6.56 refrigeration tons.
Better inputs
Useful tips
- Avoid adding a margin already embedded in the W/m² allowance.
- Separate sensible and latent loads in humid climates.
- Check minimum modulation and part-load performance, not only peak capacity.
Before relying on the result
Limitations and common mistakes
- The page is not a Manual J, heat-balance, or room-by-room design.
- Orientation, glazing, shading, infiltration, ventilation, humidity, ducts, schedules, and climate design conditions are simplified.
- Oversizing can reduce comfort, efficiency, and moisture control.
Reference
Key terms
- Sensible load
- Heat that changes dry-bulb temperature.
- Latent load
- Moisture-removal requirement associated with humidity.
- Refrigeration ton
- Cooling capacity equal to approximately 3.517 kW.
- Design condition
- Selected outdoor and indoor conditions used to size equipment.
Important note
Calculated from the entered measurements and stated coverage or quantity rules. Confirm field dimensions, waste, product requirements, structural conditions, and local codes before purchasing or building.
Frequently asked questions
Can I size an air conditioner from floor area?
Not reliably. Floor area omits climate, envelope, glazing, humidity, ventilation, and room distribution.
Should I add another safety factor?
Avoid stacking margins unless each allowance is documented.
Why show both tons and BTU/h?
They are common industry units for the same modeled capacity.
Does this include heating load?
No. Heating design requires its own outdoor condition and heat-loss calculation.