When to Replace Your AC Filter: 4 Factors to Consider

In general, most air filter manufacturers and HVAC companies recommend changing the air filter every 90 days or 3 months. That may change depending on the location of your home (e.g. EJ. dry and dusty climates), if you have pets and the age of your system and equipment.

Older systems often use fiberglass air filters, which should be replaced every 30 days. Newer systems typically use pleated filters, also rectangular ones with a depth of about one inch. You should replace them approximately every 90 days, if you don't have allergies, but AC professionals generally recommend every 45 days for maximum efficiency. A clear sign that the AC filter needs to be replaced is when the back of the unit is too hot. If the filter is heavily soiled, you may feel warm air coming out the back of the unit.

A clogged filter forces the air conditioner to work harder to keep the house cool. This will lead to more frequent air conditioning repairs and ultimately shorten the life of the unit. Reduce the load by simply changing the AC filter regularly. The only way to ensure how often you need to change your air filter is to perform a visual inspection of the filter every month. After a few months, you'll get an idea of how quickly it gets dirty.

You will need to re-evaluate if you have a new pet or if the outdoor air quality has been poor. A general rule of thumb for pleated air filters (such as those manufactured by FilterBuy) is to replace the filter every 90 days. As the filter traps more dirt, dust and allergens from the air, the efficiency of the filter decreases. Now that you have a good filter, there are a combination of factors that affect how often you replace it. Every three weeks is a good rule of thumb if you have multiple pets, live in a very dusty or contaminated area, or have severe allergies. The air conditioner filter isn't the most complicated part of an air conditioning system, but it can dramatically affect your efficiency and the air quality in your home. But how often do you need to change your oven filter? Well, it depends. The longer the filter is in place, the more dirt, dust and allergens are trapped, clogging the filter and decreasing its efficiency.

You just need to follow these three simple steps to improve the efficiency of your air conditioner by 5 to 15% by changing clogged filters. If you live in a mild climate and only use your air conditioner or heater for a few hours a day, a filter could last the entire season or up to an entire year. While these factors affect the frequency of air filter replacement, you should visually inspect the filter every month for excessive particulate buildup. The only downside to choosing a filter with a high MERV rating is that it can reduce the speed of airflow in your air conditioning unit. 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. Learn four factors that affect how often you should replace the air filter in your air conditioner: location; pets; age of system; and outdoor air quality. If you have multiple pets or live in a very dusty or contaminated area, replace your pleated air filters every three weeks for maximum efficiency.

If you purchase an older system, plan to replace the filter more often to maintain filter quality. Call the manufacturer or your favorite technical expert for advice on “the right air filter for your air conditioning system”. However, if replacing the air filter is simply not possible for an extended period, going beyond 90 days will not cause irreparable damage to your air conditioning system. As a general rule, you'll want to replace your home's pleated air filters and heating filters every 90 days. If you notice that your air conditioner doesn't cool down as it normally does or blows hot air, check if it's time for a new AC filter.