Which Air Filter is Better: MERV or HEPA? A Comprehensive Guide

When it comes to air filtration, two of the most popular options are MERV and HEPA filters. But which one is better? To answer this question, it's important to understand the differences between the two. MERV 13 filters are more efficient at removing large particles from the air, while HEPA filters are more efficient at removing small particles from the air. MERV 13 filters can remove up to 99.97% of particulates from the air, while HEPA filters can remove up to 99.99% of particulates from the air.

If you were to use the HEPA test on a 95% ASHRAE air filter, it would have an efficiency of around 50% on particles the size of 0.3 microns once they have been charged with dust. It's also difficult for many existing HVAC (heating, ventilation, and air conditioning) systems to adopt a MERV 13 due to the increased load on the fan due to the finer filtering material, which can actually cause more harm than good and reduce airflow if the system is not designed to support that type of filter. In terms of efficiency, HEPA filters are the clear winner. HEPA filters are the only mechanical air filters that are tested and certified to meet a specific efficiency with a specific particle size. This makes them ideal for residential or commercial use, followed by MERV 13-16 filters.

Filtering is a mechanical method of purifying air, which means that it works with living and non-living particles. The following table shows some of the air pollutants that air filters can capture under the MERV classification:

• MERV 8: Pollen, dust mites, mold spores
• MERV 11: Pet dander, dust mites, mold spores
• MERV 13: Bacteria, smoke, smog
• MERV 16: Viruses, smoke, smog

It's important to note that a professional opinion from an HVAC engineer is strongly recommended before attempting to update any air filter. For even better results, filtering can be combined with an air purification method such as ultraviolet germicidal irradiation (UVGI). A high-efficiency particulate air (HEPA) filter focuses on tiny particles in the air to help promote adequate IAQ. Many establishments and businesses use air filters to prevent the spread of bacteria and keep people healthy. Therefore, when a cabin air quality system uses a prefilter, such as the RESPA-CF2, the lifespan of the air conditioning system is extended and downtime is reduced, since fewer contaminants reach the filter. When looking for the best home air filter, you can find recommendations for both MERV and HEPA air filters.

While any air filter is better than no air filter, you'll find that the MERV 11-13 range air filters are perfect for most residential spaces. ASHRAE or MERV air filters are tested by testing for dust spots, which incorporate fine dust, powdered charcoal, and some cotton fragments. In conclusion, when it comes to choosing between MERV and HEPA filters for your home or business, HEPA filters are clearly more efficient at removing small particles from the air. However, it's important to consult with an HVAC engineer before making any changes to your existing system.