The longest time you should go without changing your air filter is the recommended 90 days. However, if replacing the air filter simply isn't possible for an extended period, going beyond 90 days won't cause irreparable damage to your air conditioning system. A general rule of thumb is to keep track of how long the air filter has been in place. The recommended average length of service is approximately 10,000 to 15,000 miles, which for most people is approximately every year.
But keep in mind that, as with most things related to your car, this is just a recommendation and doesn't take into account your individual driving situation. The longest time you need to go without changing the air filter is the recommended time of 90 days. However, if it's simply not possible to replace the air filter for an extended period of time, going beyond 90 days won't cause irreparable damage to your air conditioning system. However, it will put unwanted pressure on your HVAC system, resulting in poor air quality and air circulation.
The ideal is to change your air filter every three months, however, there are certain factors to consider when determining when to change an old filter. Refer to your owner's manual, which will tell you when the air filter needs to be replaced. Typically, this is every 12,000 to 15,000 miles, depending on the vehicle. If you've driven more than that since the last time you changed your air filter, it's probably time to change it.
With your family's safety in mind, if someone in your household is allergic to dust or has an asthmatic, it's best to clean or change the air filter before the recommended date to avoid any health problems. However, many homeowners are unaware of how often air filters need to be replaced, making their system vulnerable to damage. If you live in a “smaller house,” your air conditioners and ovens need to pump less air for the same amount of temperature change, which could mean fewer filter changes. One of the most important things you can do on your own to take good care of your HVAC system is to simply change your air filter on a regular basis.
However, you should be careful if every time you change the oil, the repair shop says you also need a new air filter. As a general rule, you'll want to replace your home's pleated air filters and heating filters every 90 days. On the other hand, if you use your HVAC system almost constantly, you'll need to change the filter every few weeks (especially if you use fiberglass filters). It's a general recommendation to change your home's air filter every 30 days when using less expensive fiberglass filters.
The purpose of the engine air filter is to prevent dust, dirt, and other environmental contaminants from entering the engine. Other signs that the air filter is affecting the performance of your car are sudden movements when accelerating or not responding as well as it should. In general, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days or 3 months. While most of us generally rely on HVAC unit air filters to keep the air in the house clean and fresh, some people like to be more cautious and install additional air purifiers.
The air cleaner and boiler filter replacement cycle is also affected by air outside and inside your home. A clean air filter will help your engine perform better; in newer cars, it can increase acceleration by up to 11%, and in older cars it can improve mileage by up to 14%.