Air conditioning is not just for summer — it demists windows in winter.
Systems slowly lose refrigerant and can develop smells.
Use it regularly
Run the AC for a few minutes every week to keep seals lubricated.
Signs of trouble
- ▸Air not cold
- ▸Musty smell
- ▸Strange noises when on
- ▸Water inside the cabin
Regassing
Refrigerant may need topping up every few years. A garage should check for leaks.
Cabin filter
Replace the cabin filter as recommended. See our air filters guide.
Getting rid of smells
A musty or sour smell when you switch on the air conditioning is often caused by bacteria and mould growing on the evaporator, which stays damp. Replacing the cabin filter helps, and garages can treat the system with an antibacterial cleaner. To reduce smells, switch the AC off a few minutes before reaching your destination while leaving the fan running, which helps dry the system.
Air conditioning also improves fuel economy at higher speeds compared with driving with windows open, which increases drag — though at low speeds, open windows are usually more efficient.
CAUTION: This is general automotive information, not professional mechanical advice. Always follow your vehicle manufacturer’s specifications and service schedule, and have brakes, steering, tyres, and other safety-critical systems inspected by a qualified mechanic.