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The IAQ Secret that Prevents Air Filters from Ruining Your Facility Plan

Published on 8/7/2015

When improving health is your organization's mission, it would be a shame to let poor air sneak in and ruin all of your hard work. Yet all too often poor air filtration can let bacteria, dust and even mold spores into spaces that require the highest levels of cleanliness.

There's a simple secret to ensuring the best air filtration for your facility: always use filters with a MERV-A rating that matches the required rating.

MERV — that's the Minimum Efficiency Reporting Value — is the number that describes the size of the particles captured by an air filter, or that filter's "particle capture efficiency." Values range between 1 and 16, with a MERV 16 filter stopping the smallest particles, such as bacteria. Here's the catch: the MERV defines the filter's particle efficiency at the time of installation. Over time, some filters begin to lose their particle efficiency as they are loading with dust.

A MERV-A value describes the filter’s particle efficiency after the filter gets dirty. It's this number that will best help facility managers to ensure the filter works as efficiently on the day you take it out as the day you installed it.

Some air filters have lower MERV-A values than MERV values, indicating a loss in effectiveness - and subsequent indoor air quality. In a hospital, that's bad news for patients, staff, and visitors.

Facility managers should select an air filter where the MERV-A value meets or exceeds the MERV value. For example, a MERV 14 air filter should also have a MERV-A value of MERV-14A.

Once it is time to change your filter, keep in mind that buying the cheapest available replacement doesn't guarantee cost savings. Look at it this way: if you're spending $100 on inexpensive filters, you might be hiking up your energy costs by using media that will clog more quickly — causing your HVAC system to work harder to circulate air — than a slightly more expensive filter.

Air filters are a good opportunity to capture low-hanging fruit on the money tree. For every dollar a hospital spends on air filters, it spends $7 on energy to push air through those filters — yet most hospitals neglect to evaluate their fan energy spend or filter life when considering air filters.

About the Contributor: 
Dave Blackwell is the healthcare segment manager for Camfil USA.