Can an Air Conditioner Work Without a Filter?

Even though your air conditioning system will work without a filter, experts strongly advise against it. Doing so can cause serious damage to the air conditioning system, resulting in expensive repairs. The answer to this question is yes, but it is not recommended. We understand that you may not always have a new replacement filter on hand when you need to replace your current one, but it is best to wait until you have one.

Running an air conditioner without a filter is worse than running it with a dirty one. Instead, go to the store as soon as possible for a replacement or call an HVAC professional to have it replaced. Without a filter, the air conditioner is at risk of serious and costly problems. It is never a good idea to operate your air conditioner or HVAC system without an air filter in place. The purpose of your air filter is to clean the air in your home and keep the air conditioning system free of dust and dirt. Any amount of time an air conditioner is operating without a filter could damage the system and shorten its lifespan.

It's best to get a replacement filter as quickly as possible. In theory, you can run your air conditioner without a filter for a limited period of time. However, doing so for longer than 6 to 8 hours can be harmful to your system and reduce the quality of your home's indoor air. The longer you leave your air conditioner running without a filter, the more likely you are to have problems with indoor air quality. As a result, you or others in your household may experience an increase in allergy symptoms, respiratory problems, eye irritation, or nose and throat irritation. In general, poor air quality caused by pollution, excess dirt, or mold can also cause faster damage to HVAC systems.

As the warm air passes through the cold coils, the coolant cools the air and then the air passes through the entire house. Without a filter in place, these contaminants can travel freely through the ducts and can be deposited there, which could also adversely affect health due to worsening indoor air quality. That said, one or two days of operation without a filter may not cause damage, depending on current air quality and environment. In addition, indoor air quality will be affected, which is not beneficial to anyone in your home during the hours you spend indoors. Without a filter that prevents contaminants from circulating throughout the house, indoor air quality will decrease. As dust and dirt penetrate the interior of the air conditioner, this contaminant will retreat repeatedly and remain suspended in the air.

Dirt is the main cause of air conditioners breaking down, so operating the unit without air filters installed can cause serious damage. Although most residential air filters only have a MERV rating of 1 to 4, they are usually not sufficient to filter out the smallest particles. The function of the air filter, together with the compressor motor and evaporator coils, is to prevent air contaminants from entering the air conditioner. If construction is being carried out in your area, dust and dirt in the air are likely to be higher than usual. It's important to know before buying what size filter you need, what level of protection you'll need, and if you'll need a custom air filter. In a situation like this, you should be able to operate your unfiltered air conditioner safely overnight or until the next day when stores reopen.