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Fresh Air's Professional recommendations for a variety of common issues

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Dust bunnies and cat dander causing a runny nose but the fresh outside air makes you sneeze? A ventilation unit with a High-Efficiency Particulate Air filter may be just the solution you've been searching for.


Allergies are the worst
If you’re the type of person who’s allergic to something you like, such as cats, a ventilation system can help you to reduce associated allergens in the air. Karen Johnson, wife of Fresh Air’s owner Kurt Johnson, is allergic to cats and with a system in their home running on the high setting 24/7, they’ve been able to have a cat for ten years now.


As a participant at Lewistons' 2017 Business-to-Business Trade Show said to us, “But it’s the stuff outside that makes me the most sick.” As not all allergens start in the home, there’s an option for people with outdoor allergies too. It’s called a High-Efficiency Particulate Air (HEPA) filter. The Minimum Efficiency Reporting Value (MERV) rating for a HEPA filter ranges from 17 to 20.


The MERV rating scale was designed by The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). A link to ASHRAE can be found at the bottom of this page. The scale is fairly straightforward, filters marked as being 1-4 cover the simple, low end filters. 5 through 13 are medium range filters and 14 to 16 are considered high efficiency, just not quite HEPA. Quite simply, the higher the MERV rating, the smaller the particles it is able to filter out.

So what makes these HEPA filters so special?

Great question. To have earned a MERV rating of 17 or higher it must

be able to filter out contaminants down to a size of 0.3 Microns, also

called micrometers, which are very small. There are some filters that

can take care of even smaller than a MERV 20 though, those are

called Ultra-Low Particulate Air (ULPA) filters,though in most cases

they’re not necessary. A MERV 17 is primarily what we sell when it

comes to HEPA, above that and you’re getting more towards a

hospital’s “clean room” level of filtration. While that’s not a bad thing,

it’s usually more than what the average person needs.


MERV 17 can filter out all bacteria, all combustion smoke, lead dust,

mold spores, hair spray, cement dust, pollen dust mites and several

others. MERV 18 adds carbon dust, MERV 19 adds viruses and

MERV 20 can filter out unspecified, smaller fine particulates. For most

of our customers a MERV 17 is actually more than what they need. For

people with chronic allergies, asthma or other respiratory issues looking

for a way to breathe easier, MERV 17 is the way to go.



What else should I consider when looking into filtration options?

Odors from outside are also a factor when selecting a filter. If you have neighbors

who regularly smoke marijuana or tobacco outside, or often have camp or bonfires-

preventing these particulates from entering your home is a healthy decision. Who wants to smell the fresh spray of a skunk or the strange and “exotic” foods your neighbor’s always trying? Well maybe some people do, but for me I’ll stick with a HEPA filter so none of that bothers me.


As someone who is sensitive to smells, I find that filtering the air as much as reasonably possible is the best way to stave off headaches. You can read more about sensitivities in the Multiple Chemical Sensitivity (MCS) section, which mostly recommends a HEPA filtration as well, but there are some helpful links if you think you may suffer from this condition.

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