AC TOOL
Air Conditioner Horsepower and Cooling Capacity Reference
Enter the room’s usable area, west-facing exposure, top floor, ceiling height and number of people to estimate the cooling capacity range and understand the difference between horsepower and power consumption.
An air conditioner should be selected based on the model's rated cooling capacity matched to the room's heat load, not horsepower alone. This tool provides an initial range for a single residential room and cannot replace an on-site heat load calculation.
Result
After filling in the details, click "Calculate result".
Calculation method
- This is a publicly assumed tool model, not an area formula set by the EMSD or the Consumer Council: 180–220W of cooling capacity per square metre, with a ceiling height of 2.6 metres as the baseline and proportionally more for higher ceilings.
- West-facing or top floor: add 10% each; for more than 2 people, add 120W of cooling capacity per extra person. These are tool-based scenario assumptions, not engineering factors guaranteed to apply to every room.
- 1 square feet = 0.09290304 square metres; 1 kW of cooling capacity is approximately equal to 3,412 BTU/h. Horsepower is compared using common nominal ranges, but the actual model must be checked for its kW or BTU/h rating.
- For open-plan, large spaces and commercial premises over 60 square metres, single-room cooling capacity results do not apply; glass area, insulation, cooking, ventilation and heat from equipment are not fully included.
- Cooling capacity is not the same as power consumption, and you cannot put cooling capacity in kW directly into an electricity cost calculator. The reference source supports selecting a unit according to the environment and rated cooling capacity, but does not certify the coefficient of this tool.
Frequently asked questions
- Does a 1 HP air conditioner equal the power consumption of 1 HP?
- No. Market horsepower is mainly a common way to refer to cooling capacity and does not equal electrical input. When choosing a unit, compare the rated cooling capacity; when calculating electricity cost, use input power or actual energy use.
- Do west-facing units or top floors always need an extra half horsepower?
- Not necessarily. Heat load is affected by glass, insulation, floor height, sunlight and usage. The tool is only for contextual adjustment; it cannot mechanically mean adding half a horsepower in every case.