While you need to have your HVAC system serviced once a year, you should change the filter a lot more regularly. Depending on the amount of use the system gets, every 3 months is ideal. However, under certain conditions, you may want to consider replacing it more often than that. When checking the filter, if you notice it is damaged or has become wet or damp, then it should be replaced immediately. If not, dangerous toxins such as mold spores can be released into the air and dispersed through the house.
Changing the filter as often as once a month is beneficial for some homes. This might be necessary for larger families or those with pets. If anyone living in the home has allergies or if there are any smokers in the house, these are also reasons to change the filter more frequently.
Your homes outdoor environment should also dictate how regularly you change HVAC filters. For example, if there is a lot of construction going on in the neighborhood, if you live in an agricultural area or even if there have been wildfires in the surrounding area, it would be wise to replace filters often.
Replacing your homes HVAC filter regularly is a simple and effective way to maintain a healthy indoor air quality.