I’ve Got You Under My Skin

As part of the natural repair functions our bodies go through each day, one of those  necessary functions is both good and bad. Each day the body sheds over 1,000,000 skin flakes from your body. This is a natural process that allows the old, used skin cells to flake off (so to speak) and be replaced with new skin cells.

Again, this process takes place every day for everyone of us. So, for example, if you have a family of four they will generate 4 million skin flakes a day. These skin flakes range in size from less than 1 micron to 30 or 40 microns in size. Over 30% of the dust you see in the air ( dust particles in the sunlight through the window) are skin flakes…… Oh yes they are!

Okay! So what happens to these skin flakes? Well, some of them are picked up by the vacuum and those that stay airborne may be removed through the filter in located in the return air side of your heating/cooling system. The rest are eaten. Yep, eaten by dust mites.

For all the bad press the dust mites get ( and there is a reason for that)  they are natures own trash disposal system. You see, dust mites feed off of skin flakes.  We call them dust mites since the term “skin flake mites” is too long and rather disgusting. Yet, that is exactly what they do. Munch on your dead skin!

When your body is at rest whether sleeping, or sitting on the couch, your skin cells are being shed. These flakes tend to stay in place longer and thus become the better feeding grounds for dust mites. When the dust mites eat your dead skin they produce small pellets or fecal matter. They produce up to 20 of these digested skin pellets each day. It is these pellets or “dust mite feces” that affects millions of allergy sufferers.

Dust mites themselves are relatively large so they seldom become airborne. The dust mite feces or pellets are very tiny easily become airborne.  They are aspirated into the body through the lungs and for many people these pellets can cause some severe allergic reactions for a number of individuals.

No matter how often you dust, vacuum and clean your home you will have some of these dust mites in your enclosed living environment.  Since the main allergen is the dust mite feces, the removal of these tiny pellets is essential.

Since the dust mite feces is light and can be airborne it is essential that the filter or filtering device you have in your heating/cooling system be effective on removing small, less than 10 micron sized particles. In addition, you need to keep the fan in your heating/cooling system to run all the time so setting the fan switch to “fan on” on your thermostat will keep the air moving and continuously draw the airborne particulate back to the filter.

Pure Air Systems has been making HEPA and Carbon based air filtration systems since 1985. These commercial grade HEPA units are designed to attach to any forced air, ducted heating/cooling system and can remove 99.99% of all airborne particles 0.3 microns or larger. These systems are extremely effective at removing dust mite feces and other airborne allergens.

For more information on the complete product line please go to our website at: www.pureairsystems.com

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The Truth About Air Filter Efficiency

It is always interesting to see how companies that manufacture air filters, especially those for the residential market, use images of dust mites, dirt, dander and other graphic photos to illustrate the significance of using their filter if they really want to rid their home of these nasty airborne creatures.

Usually these companies compare the efficiency of their filter against the standard air filter that you use in your heating/cooling system and show how theirs is much more effective in removing these harmful airborne allergens.

For the most part, all of the air filters available from the retail stores are made from similar filter media and have similar efficiencies. Some are pleated, some aren’t, some are washable and reusable and many are not. Almost all of them have a cardboard frame and come is a wide variety of sizes.  And, their prices vary from less than $1.00 each up to $10.oo or more per filter.

When shopping for these filters you will notice that many or most of them now come with a MERV rating label to indicate their overall efficiency.  These MERV ratings (which are an extension of the old ASHRAE ratings) indicate their filtration efficiency in relationship to how well they remove various sizes of airborne particulate.

In truth, what you really want is a filter that removes as much of the less than 5 micron in size particulate but doesn’t have a high resistance so it won’t affect the performance of your HVAC unit. Typically a MERV 7 or 8 rated filter offers the best combination of particulate removal (small particles) with minimal adverse affect on your heating/cooling air flow.

While it may seem that using a filter with a higher MERV rating than 8 would be better, the truth is that as a filter starts to get dirty and gets a layer of dust on the filter surface, the efficiency of the filter actually gets better as the filter loads up.  And, as the filter gets dirtier the pressure drop or resistance across the filter goes up as well.

Therefore, if you start out with a MERV 9 or higher rated filter you will have  a slightly higher efficiency at first but also a higher initial pressure drop as well. And as the filter loads up the pressure drop will increase rapidly and the air flow across the air handler or HVAC system will drop quickly.  This is why using a MERV 9, 10, 11 or higher rated filter usually requires you to change the filter often, usually once a month verses once every three months for a MERV 8 or lower rated filter. And, these higher rated filters are more expensive.

Pure Air Systems offers a line of MERV 8 rated BioPanel dual-layer polyester ring panel filters that are less expensive than the higher rated media filters, fit more tightly in the filter frame, have zero leakage around the filter and have a much higher dust holding capacity with a lower pressure drop or resistance over the the life of the filter.  These commercial grade filters are not available in the retail market but can be purchased directly from the Pure Air Systems website.

For more information on filter efficiency and the BioPanel filters available from PAS go to our website at: www.pureairsystems.com.



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