Clean Air Services provides some guidelines to follow in determining when to change your residential HVAC air filter. They are:
- At the beginning of the hot and cold seasons
- During and after any significant home renovation
- After a professional has completed the cleaning of your ducts
- When a decrease in flow is noticed at the registers
- Upon inspection, you note that the filter is loaded up with dust or debris or is damaged
Residential heating and air conditioning equipment presents several challenges for the homeowner from the standpoint of air filtration. The first limiting factor involves filter depth. Several older homes have an air handler with a one inch slot for an air filter inside the unit.
This filter is changed by removing the door to the unit and removing and reinstalling the filter. Newer homes have a filter grille, located at the return air opening.
This grille is hinged and can be opened to expose a track for a one inch filter. In short, regardless of where the filter is located in a residential unit there is usually only one inch in depth allocated for the air filter.
Residential air purification units such as residential HVAC filters will not generally be sufficiently efficient to remove allergens such as mould spores from the air.
For these applications or to remove offensive odours and gases, a free-standing residential air purification unit is recommended.