Cut-to-size air filters offer the same benefits as regular air filters, with one addition: you can cut them into any size or shape you need. But is it safe to cut an air filter? The answer is yes, as long as you know what you're doing and the filter doesn't become too weak from the cut. Bending or cutting the filter can decrease its structural integrity, leading to a performance problem and potentially costly repair. It can also create unsafe conditions.
If the filter is too big, you'll need to return it. Don't be tempted to cut it to make it look good - this can create air gaps and allow contaminants to pass into the air. If the filter is too small, it won't cover the entire space and may let dust and dirt through. When using a cutout to place the air filter in a window air conditioner, consider the thickness of the filter.
You may want to go a little bigger or smaller depending on where you need to place it. A higher MERV rating indicates that the filter has a finer mesh and is capable of removing smaller particles from the air. The air filter installation tape runs around the perimeter of the ventilation grille where you want to install the filter. My favorite use case for cutting charcoal for air filters is in a window air conditioner that is located in a work area, such as a garage or workshop.
We recommend removing the existing filter and measuring it to confirm the actual dimensions. In short, yes, you can cut an air filter if you know what you're doing and if it doesn't get too weak from the cut. However, don't be tempted to run your air conditioning system without a filter for the time being - this will cause dirt and debris to accumulate on the fan, slow down airflow, degrade performance, lower air quality, and generally create a big mess that you will have to pay to fix or clean later.
