Summer cooling costs: fans and seasonal electricity
Calculate seasonal fan and cooling electricity with realistic hours and active days, alongside official guidance on reducing heat in the home.
Reviewed 8 November 2026. Worked figures are hypothetical unless explicitly identified as a sourced reference.
Start with heat entering the home
Before assuming you need a new appliance, review shading, ventilation and avoidable indoor heat. The UK Health Security Agency's keep-cool checklist, which applies to England, advises shading windows, opening them when it is safe and cooler outside, and reducing unused electrical equipment. Follow current local guidance elsewhere in the UK.
Cooling costs should never be the only consideration during hot weather. The checklist identifies homes and residents more vulnerable to overheating, and explains when ordinary cooling measures may not be enough. Follow its current safety advice rather than interpreting a cheap running-cost estimate as proof that a device will protect someone.
A seasonal fan example
Assume a fan draws a constant 40 W for eight hours on each of 30 days. Energy is 40 / 1,000 x 8 x 30 = 9.6 kWh. At a fixed teaching rate of 25p/kWh, the seasonal cost is 2.40 pounds. These are invented inputs, not a measured product result or a current tariff. Enter your own power, time and active days in the appliance calculator.
If use extends to 60 days, the same assumptions produce 19.2 kWh and 4.80 pounds. This shows the effect of the schedule; it does not establish cooling performance, comfort or suitability for a particular temperature.
Compare equivalent outcomes
A fan and air conditioner perform different jobs. Do not infer that the lower-watt device supplies the same cooling. For equipment whose compressor cycles, a full-power calculation may overstate or understate a particular operating period. Prefer measured consumption under representative conditions, and distinguish electrical input from advertised cooling capacity.
Use the measured-energy tool for matching observation boundaries, or the household planner for seasonal rows. Record the room, settings, weather and hours alongside readings before comparing two days. Different outdoor temperatures can explain a cost difference without proving one appliance is more efficient.
Include the costs of buying
A low seasonal electricity total does not justify a purchase on its own. Compare upfront price, fitting where required, storage, filters and maintenance in the ownership-cost tool. Follow the equipment instructions, including ventilation and exhaust requirements.
The official checklist supports the practical home checks above. All wattages, durations and arithmetic here are our illustrative scenarios; they are not sourced product specifications or guaranteed savings.