MERV stands for Minimum Efficiency Reporting Value, and it is a nationally recognized measurement system used to rate every air filter. The MERV rating measures the effectiveness of air filters in capturing particles between 0.3 and 10 microns in size. The higher the MERV rating, the better the filter is at trapping specific types of particles. The MERV rating scale ranges from 1 to 20, with 1 being the lowest and 20 being the highest.

Here is a breakdown of the MERV rating chart:

• MERV 1-6: These filters are the lowest range of MERV ratings and are typically made of aluminum or mesh. They are designed to capture larger particles such as dust, pollen, and carpet fibers. They are not recommended for people with allergies or respiratory problems.

• MERV 7-12: These filters are capable of capturing smaller particles such as mold spores, pet dander, and smaller dust particles. They are recommended for residential use and can provide a good balance between air filtration, air flow, and affordability.

• MERV 13-16: These filters are capable of capturing even smaller particles such as bacteria and tobacco smoke. They are recommended for people with allergies or respiratory problems and can last up to six months before needing to be replaced.

• MERV 17-20: These filters are the highest-rated filters and are typically used in hospitals and clean rooms. They are capable of capturing the smallest particles such as viruses and are not recommended for residential use.

It is important to note that selecting the ideal MERV rating for an air filter is a delicate balance between an HVAC systems capabilities and the indoor air quality you want to have. If you have allergies or respiratory problems, it is recommended to choose a filter with a higher MERV rating. However, it is also important to ensure that the filter does not decrease the air flow and strain your HVAC equipment.