AC is usually the single biggest contributor to a household's electricity bill, but a poorly maintained or poorly used unit can push that cost up significantly beyond what's necessary.
A dirty filter forces the compressor to work harder
When airflow is restricted by a clogged filter, the compressor has to run longer to reach the set temperature, consuming more electricity for the same result. This is the single most common — and most fixable — cause of excessive power use.
Setting the temperature too low
Every degree below what's actually needed increases power consumption. Setting an AC to 16°C when 24°C would feel perfectly comfortable makes the compressor work continuously rather than cycling on and off efficiently.
Using AC without letting it cycle off
A well-sized, well-maintained AC should cool a room and then cycle the compressor off periodically, only running the fan. If it's running the compressor constantly without ever reaching the set temperature, something is wrong — likely low refrigerant, a dirty filter, or an outdoor unit with poor airflow (see our article on AC not cooling properly).
An aging or oversized/undersized unit
Older units are generally less energy-efficient than modern inverter models. Meanwhile, an undersized unit for the room will run constantly trying to keep up, and an oversized unit cycles on/off too rapidly — both waste energy in different ways.
Practical steps to reduce your bill
- Clean the filter every 2–4 weeks depending on usage
- Set the temperature to 24–25°C rather than the coldest setting
- Keep doors and windows closed while the AC runs
- Make sure the outdoor unit has clear airflow around it
- Schedule a proper cleaning if it's been more than 3 months