The intervals at which you need to change your home ac filter will depend on the variables of the home you live in.
What type of air filter are you using?
If you are using the less expensive filters that are designed to be changed monthly, then that is when you need to change them. These filters get dirty quickly and are not designed to be used for extended periods of time.
If you are using the filters that cost more and are rated for longer periods, you can generally change it according to what the packaging states but if you notice it’s a lot dirtier than normal, the it won’t hurt to changer it sooner than what the packaging is showing.
The conditions in your home play a large roll on when you will need to change the filter. If you have a lot of pets, live in an area where there is constant dust in the air or have poor indoor air quality for other reasons, then you will probably end up changing them more often.
People who suffer from allergies can benefit from the higher priced filters that are designed to remove pet dander and pollen from your home. While these are more expensive, they can really help an allergy sufferer.
There is a debate as to whether the more expensive filters are any better than a standard filter. The best way for you to decided is try them yourself and see if you notice any difference in air quality in the home between the two filters.
One thing is for sure, if you don’t change your dirty filters then it will end up causing you issues with your AC unit. On service calls where an AC system has stopped working, more than once it has been found that the air filter was completely plugged with dirt. Your AC required air to move through the system and if there is no air supply, it will keep trying to compensate and eventually shut down.
So, remember to keep you AC filters clean throughout the year.