It is possible to run an air conditioner without a filter, but it is not recommended. Doing so for more than 6 to 8 hours can cause serious damage to the system and reduce the air quality in your home. Depending on the environment, a day or two of unfiltered operation may not cause any damage. However, it is always a risk to the system and should be considered carefully.
When you don't have a spare filter and stores are closed, you may be tempted to run your HVAC unit without a filter for a short period of time. However, this can cause dirt and debris to recirculate throughout your home, leading to poor air quality and potential damage to the mechanical components of your system. Additionally, dirt and dust that passes through the system can clog the condensate drain. Air filters are essential for keeping your air conditioner running efficiently and protecting it from dirt and dust.
They also help keep debris out of the air ducts and trap particles that can affect your health. Therefore, it is important to replace the filter often enough and never operate your air conditioner without one.