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Merv Mythbusters and IAQ FAQs

It’s the heart of summertime, when we celebrate and embrace the outdoors…but also prefer to dart back inside for a respite from the heat, allergens and other irritants of the season. When it comes to Indoor Air Quality (IAQ), today’s homeowners are more knowledgeable than ever, and willing to take action to address their issues and needs.

  • 28% of homeowners say they want better air purification1
  • 75% rate dust, airborne allergens, and viruses/bacteria as their top three IAQ concerns2
  • 40% use two or more portable air purifiers to cover multiple home spaces2

Filtration solutions are a common way to address airborne allergens, and MERV ratings are the primary method for measuring the efficiency of a filtration product. In this blog, we offer insights into the MERV system, address some common misconceptions and provide tips to help you deliver the best filtration solution for your customers.

The meaning and myths behind MERV ratings
MERV stands for Minimum Efficiency Reporting Value. Modern filtration solutions are evaluated by the MERV ratings system on their ability to remove particles from indoor air – from microscopic bacteria and dust mites to thick tobacco smoke and more.

MERV ratings apply to both residential and industrial filtration solutions, and range from 1 (low) to 16 (exceptionally high filtration). The average home’s system typically carries a rating from 4 to 10 or more. But facilities in which air quality is critical, such as high-tech clean rooms or surgical centers, will have filtration systems that feature ratings as high as 14 to 16.

The MERV system has proven to be a fair, consistent solution for judging filtration performance. But it’s important to address some MERV myths and misconceptions that could affect the expectations of homeowners. Use these FAQs to dig deeper into MERV ratings and what they may, or may not, tell you.

Q: So the higher the MERV number, the cleaner the air, right?

  • Not necessarily. Loose-fitting filters can create gaps and air bypasses in the spaces between the filters and the frame, which allow unfiltered air to circulate back through the home and effectively reduce the MERV number. Remind your customers to always have an experienced HVAC professional such as yourself install and inspect the system to ensure a proper, tight fit.

Q: When is an 8 not really an 8?

  • As with any product, filters can vary in quality and efficiency – even filters that carry the same MERV rating. For example, some filters could perform at a “low” 8 while others achieve more advanced particle removal – closer to a 9. When you’re talking about taking harmful microscopic elements out of the air, that seemingly small span can make a big difference. Make sure your customers know they should choose proven filtration solutions from trusted brands.

Q: Is filtration efficiency the only thing to be concerned about?

  • To balance all homeowner needs and achieve optimal results, you should consider three key characteristics:

Efficiency: As discussed above, how many different particles are captured by the filter? This chart provides a handy reference guide.

Ratings for MERV

Pressure Drop: How does the filtration solution affect or restrict air flow? How does this impact energy use and costs?
Filter Life: How much dust and other particles will the filter hold and how long will it stay effective? How often does it need to be replaced?

As an HVAC expert, you can offer the guidance customers need to enjoy cleaner, healthier air for summer and beyond – to optimize their IAQ and personal comfort.

Save the season with the Honeywell Home F300 Electronic Air Cleaner
The Honeywell Home F300 Electronic Air Cleaner makes IAQ easy. It uses electrostatic technology and three stages of filtration to capture 99%3 of all particles that pass through it – including summer’s pesky pollens and other allergens. In addition to an advanced MERV rating, the Honeywell Home F300 offers these convenient features:

  • Whole-home coverage – so your customers won’t have to hassle with lugging around portable air purifiers
  • Washable cells – eliminating the cost of ongoing filter replacement
  • Very low pressure drop
  • Compatibility with all gas, oil and electric forced warm air furnaces
Honeywell Home F300 product image

Learn more about why the Honeywell Home F300 Electronic Air Cleaner is the superior choice for maximizing summertime IAQ. Visit our website for full product details.





1 Decision Analyst’s American Consumer Opinion Panel, 2008-2014

2 American Home Comfort Study, 2006

3 Based on independent lab testing