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Should Your Air Filter Be Low or High Efficiency?

When it comes to purchasing an air filter, you may be tempted to spend more money on a high efficiency model. But does it really help keep your home’s air cleaner than a lower efficiency model?

Air filter efficiency is rated by the Minimum Efficiency Reporting Value, better known as MERV. This rating is determined by how effective the filters are at filtering certain particles from the air. MERV ranges from 1 to 20, with the highest ratings (17-20) being reserved for HEPA filters. Most systems aren’t equipped to handle HEPA filters, and even some of the higher level MERV rated filters (up to 16) may not be recommended for your system. That’s why it’s always important to consult a professional before switching filters.

For those that are curious about the different levels of MERV and the typical uses for each type of filter, we’ve compiled this list:

MERV 1-4: These filters have a dust spot efficiency of less than 20 percent and the arrestance can range from 65 to 85 percent depending on the filter. These filters are ineffective against particulates less than 10 microns, but can catch common airborne offenders such as pollen and dust mites.

MERV 5-8: With a dust spot efficiency of up to 35 percent and arrestance levels between 80 and 90 percent, these filters are a definite step up from MERV 1-4. They can handle particle sizes between 3 and 10 microns, including mold spores and cement dust.

MERV 9-12: These work well with most home systems, providing improved air quality without putting too much pressure on the system. Depending on the filter, dust spot efficiency can range from 40 to 75 percent, and arrestance can reach 95 percent or more.

MERV 13-16: These filters rate a dust spot efficiency up to 95 percent and arrestance of over 98 percent. Capturing particles from 0.3 to 1 micron in size, these can capture bacteria and tobacco smoke. Typically, these are used in hospitals and commercial buildings where air quality is paramount.

If you’d like help finding the right air filter for your Lorton area home, contact HVAC & Plumbing Unlimited INC today.

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