How often you need to clean the filter in your air-conditioner for maximum efficiency

When was the last time you cleaned the filters in your air-conditioning unit? "The filter is probably the one thing that you, as the owner of the heat pump, needs to take care of," says Andre Morrisby, the general manager of an air-conditioning business in Hobart, Tasmania. "If you clean regularly, every two to three weeks, depending on your home … it will increase the efficiency, it will make the machine run better and you will be warmer," Mr Morrisby says. If you run a tight ship, dust regularly and are generally neat and tidy, you might get away with cleaning it every "four weeks" Mr Morrisby says. When asked about switching the heater on in the morning, Mr Morrisby says "the most efficient way to run a heat pump is to leave it running overnight".