The Dangers of Running an Air Conditioner Without a Filter

Operating an air conditioner without a filter is not recommended and can be dangerous to the health of the air conditioner and the people living in the home. The Environmental Protection Agency (EPA) states that the concentration of air pollutants inside a home can be two to five times higher than concentrations found outdoors. This is why it is important to get a replacement filter as soon as possible when needed. We measure how well an air filter removes dust, pollen, and smoke from the air, and how freely it flows through the filter at any fan speed.

We also estimate annual costs for replacement filters, based on manufacturer recommendations for when to change them. It may be cheaper to buy filters in bulk. Although an air conditioner will continue to work without a filter, it is never recommended to do so. Increased circulation of particulate matter in the area could mean faster damage to your air conditioner when operating without a filter.

Not only does an air filter trap particles and protect the air conditioner, but it also keeps debris out of the air ducts. Running your air conditioner without a filter for more than 6 to 8 hours can cause serious damage to your system and significantly reduce the air quality in your home. When you run your air conditioner without an air filter in place, the air conditioner sucks in “dirty air” and circulates that air back to your home. It is important to know before you buy what size filter you need, what level of protection you'll need, and if you'll need a custom air filter.

Dirty filters specifically have less surface area to absorb debris and therefore don't perform as well as a clean filter. Another effect of running your air conditioner without a filter is the clogging of the condensate drain, which serves to remove additional liquid accumulated during the dehumidification process. Again, while it's important to select the right MERV rating for your specific situation, operating your air conditioner without a filter poses more serious risks that can lead to breakdowns or additional repair costs. While air filters are generally good at filtering this dander, operating the air conditioner without a filter poses an additional risk of damage to the mechanical components of your HVAC system and the health of your pets. The purpose of your air filter is to clean the air in your home and keep your air conditioning system free of dust and dirt, so it's important to run your air conditioner only with a filter installed. Although most residential air filters have a MERV rating of only 1 to 4, these are usually not enough to filter out the smallest particles.

By trapping these particles inside your fibers, the filter keeps them out of the HVAC system, helping to protect your family and your air conditioning equipment. Although there are specific situations where this may be acceptable for a very short time, in most situations, running your air conditioner without a filter can be disastrous.