Cooling Load Ballpark Estimator: Tons per Square Foot

Units

How to use it

Review the methodology below the calculator to make sure it aligns with your project's requirements, then:

  1. Choose US or metric units.
  2. Enter the project's floor area.
  3. Choose the building type: type part of a name to search, such as "school" or "restaurant", or click the arrow to see the whole list. Try neighboring building types too, to see the full range of loads and home in on the right one for your project.
  4. The low, average and high estimates of occupants, lights and other electrical load, and refrigeration appear in the results.

Ballpark estimate

Enter the floor area.

LowAvgHigh

A pre-design ballpark from historical check figures, not a load calculation. Blank cells: the figures give only an average for this building type.

Step-by-step guide: How to Use the Cooling Load Ballpark Estimator

Methodology

The calculator estimates a building's occupants, lights and other electrical load, and refrigeration (cooling) from its floor area and building type, using check figures of what buildings of each type have historically had:

  • Occupants = floor area ÷ floor area per person
  • Lights and other electrical = floor area × watts per square foot
  • Refrigeration = floor area ÷ floor area per ton, and 1 ton = 12,000 Btu/h (3.52 kW)

The results give a low, average and high estimate for building types whose figures span a range, and only an average for the others. Low refrigeration corresponds to the most square feet per ton.

In metric units, the same figures are converted to square meters (1 ft² = 0.092903 m²).

Example. For a 10,000 ft² general office building, the calculator gives 35.7 tons (428,571 Btu/h) of refrigeration on average, with a range of 27.8 to 52.6 tons, and 25,000 W of lights and other electrical on average.

What it is for

This is a pre-design ballpark: an estimate of the cooling load before a full analysis has been done, or a sanity check of a load calculation's result. It is not a load calculation. The check figures take no account of the inputs a load calculation uses, such as construction, climate, orientation, glazing or ventilation. As buildings, lighting and equipment become more efficient, the watts and tons trend lower than these historical figures.

For a quick look at a single space, the coil selection calculator and the psychrometric calculator work from airflows and air conditions. For a full load calculation, see our cooling load/heat load calculation services.

Top