Free Engineering Tool
HVAC Load Calculator
Estimate the cooling and heating load for any room or building. Enter your space details and local design conditions to get an instant peak-load estimate and a recommended system — the same basis used for equipment selection.
1 · Your Space
square metres (m²)
metres (m)
Sets typical internal heat gains
2 · Design Conditions
peak °C at your location
coldest °C at your location
°C set-point
Drives solar intensity
Glazing & orientation
Sets envelope U-values
3 · Occupancy
Typical occupants in the space
Affects latent cooling load
Total Cooling
—
kilowatts (kW)
Cooling
—
BTU/hr
Capacity
—
tons (TR)
Load Density
—
W/m²
Where the Cooling Load Comes From
Total Heating
—
kilowatts (kW)
Heating
—
BTU/hr
Load Density
—
W/m²
Safety Factor
+15%
applied
Where the Heat Loss Goes
Suggested for this load
—
—
Cooling capacity to install
—
Approx. fresh air
—
Heating capacity
—
Floor area basis
—
Need a stamped calculation report?
This is a preliminary estimate. For a full professional load calculation with drawings, request a quote from our engineers.
About this estimate. This calculator estimates peak cooling and heating loads using standard heat-balance methods — the same peak-load basis used for HVAC equipment selection. Results depend on the conditions you enter and use engineering defaults for U-values, solar gain and internal loads. It is intended for preliminary sizing and budgeting. For projects requiring stamped calculations that account for building thermal mass, detailed solar timing and code-specific ventilation, request a professional report.
Method: sensible + latent heat-balance equations · latitude-based solar model · U-values per standard building references. No proprietary design-condition data is used.