Please note that due to the high demand for portable air conditioners we are currently unable to provide next day delivery

What Power do I need? BTUs and kWh explained


BTU s a unit of measurement of the power used by air conditioning units in the UK and the USA, designating British Thermal Units. This is the measure of the amount of heat needed to raise the of temperature of one pound of liquid water by one degree from 60° to 61° Fahrenheit, while maintaining a constant pressure. Another common measurement is kWH (kilo Watt hours) - and the power of all our air conditioners is given in both kWh and BTUs.
The number of BTUs required from an air conditioner should also take into account two key factors: the size of the room, plus the amount of heat being produced by people and machines within the space (remember to include ceiling heights in your assessments).
However, another thing to consider is window size and the direction in which the window faces. The light received into a room is a significant factor in the temperature the room maintains. For example, South-facing conservatories can get very warm, even in Spring and Autumn and will require a more powerful air conditioner than their area or volume would suggest.
We advise purchasing an air conditioner with a minimum output 8000 BTUs as this is the minimum BTUs required to cool a small room (18sq/m) on a hot day. Medium rooms (24sq/m) need around 9,000 BTUs and larger rooms and office spaces (36sq/m) require at least 10,500 BTUs.
For ease, we have organised our air conditioners in to the following categories of room size and application:
Small/Medium Rooms
Outdoor Spaces/Warehouses
Offices/Small Commercial
If you would like help selecting the right power air conditioner - please call our friendly technical services team.