The air filter is one of the dirtiest parts of the house. Its where all the dust, dirt, bacteria and fungus from the air gets trapped. Over time the deposits in the air filter can become so thick that the air flow through it is blocked which will not only lower the efficiency of the heating or cooling system, but the reduces air flow to the heating /cooling unit can damage it or cause it to overheat which is a serious fire hazard.
The air filter is usually found behind a vent that takes the air out of the room. It's called a return. You may have more than one filter in your home so the first time its worthwhile identifying all the returns and checking each one for a filter so in future you know what you have to do. Also keep in mind that some types of filters are disposable and you should not attempt to clean and reuse these.
To clean the filter:
* Access the return vent, using a ladder if it is placed high on a wall or ceiling
* Open the vent there is usually a screw or a latch holding it in place
* Once the vent is open, reach inside and remove the filter. Different makes have different ways of mounting the filter, but they are all designed for easy removal. If you have problems, check the manufacturer's website for removal instructions.
* Take the air filter outside
* Use a brush to remove all the caked dirt and debris sticking to the filter
* Next use a vacuum to suck the remaining loose dirt from the filter
* Now set your vacuum to the blower mode and blow out any remaining dirt from the filter
* Use a garden hose to wash the filter letting water run through it in the reverse direction of the air flow (from the back to the front).
* Shake out any excess water and leave the filter in a dry well ventilated area or in the sunlight to dry.
* Once it is completely dry it can be put back in place.
While cleaning the air filter is normally part of a domestic cleaning services duties, there may be times when you need to do it yourself (when guests are coming and the air filter smells), so it is a good idea to be prepared to undertake this yourself if you have to.