It is generally recommended to replace your air filter every 3 to 6 months, but this can vary depending on factors such as the type of filter, the level of pollutants in your environment, and whether you have pets. Check the manufacturer's guidelines for specific recommendations and be sure to inspect your filter regularly for any signs of dirt or damage.

MERV (Minimum Efficiency Reporting Value) is a standard that rates the effectiveness of air filters on a scale from 1 to 16. The higher the MERV rating, the better the filter is at trapping smaller particles.
For residential use, a MERV rating between 8 and 12 is usually sufficient. However, it's essential to consider your specific needs and the recommendations of your HVAC system manufacturer to ensure optimal performance without putting unnecessary strain on your system.

It is crucial to use the filter size recommended by your HVAC system manufacturer. Using the wrong size can lead to reduced efficiency, increased energy consumption, and potential damage to your system. If you are uncertain about the correct size, check your system's manual or consult with a professional. It's always recommended to use the right filter size to ensure proper air circulation and filtration within your HVAC system.