by Deborah Percy

Created on: October 29, 2009

Airborne particles are removed from the environment and prevented from passing through warm air heating systems via their filtration systems. These serve the function of protecting the furnace, particularly the fan. Some filters may also improve the quality of air in the home.

The filter should, generally, be checked monthly and if daylight cannot be seen through it then replacement is over due, it is common to replace filters monthly. If it is cogged with dirt the performance of the furnace or the air conditioning unit will be negatively affected, this can lead to breakdowns and costly repairs.

When checking or replacing the filter turn off the electrical power at the circuit breaker. The filter will be located along the channel that draws in the cold air towards the furnace, called the return, it is usually near the blower. There may be two filters. Furnace model designs can be very different, so the filters can be hard to find, but they are supposed to be easily accessible for regular changing.

Finding the filter is usually the hardest part, it should slide out easily. The arrow on the edge of the filter should point towards the blower, in the direction of air travel, when a new filter is inserted.

The filter must be cleaned or replaced regularly in order to perform effectively. The frequency will depend on many factors but will usually be at least once a year but often monthly. Disposable fibreglass filters are usually designed to be replaced every 30 to 90 days, with a similar time span for pleated filters. The furnace manual, manufacturer or the installer should advise on the type of replacement filters required.

For some households changing the furnace filter can mean replacing the old system with an electronic air cleaner (EAC). This should be done by a HVAC contractor. Modern EACs boast minimal maintenance, but that is does not mean, none at all. They do require some cleaning. Some models have cells that must be washed but that can go into the dishwasher, others have disposable particle catchers which need to be replaced. EACs are very effective at removing all sorts of small particles from the atmosphere and are easy to maintain.

Whether it is a conventional furnace filtration system or an EAC there is always a need to clear away all the particles that have been removed from the air by washing or disposing of them.

Learn more about this author, Deborah Percy.
Click here to send this author comments or questions.