Air Filtration For Dummies

The device that you or your HVAC contractor changes once or twice a year is designed, primarily, to keep the cooling coils clean. It has very little effect on the removal of airborne particles that maybe harmful to your health.

These general duty air filters are comprised of very open mesh or pleats that allow air to pass through easily but capture larger dust and dirt particles to minimize any deposit of dirt on the cooling coils which could, over time, significantly reduce the efficiency of the coils and also put dirt on the blower wheel.

Dust particles you can see are about 20 microns in size or lager. As a comparison, your hair is about 100 microns in diameter. However, airborne particles that may harm you body when inhaled are usually smaller than 1 or 2 microns in size. The efficiency of the general duty air filter on these sized particles is about 25% at best. Meaning your health is not protected in any way from indoor airborne contaminants with these general duty filters.

Perhaps the best way to get some real basic information on how filtration actually works is to go to the Pure Air Systems website. ..  There you will find a section entitled “Pure Air University.” This is broken down into simple sections detailing how filtration actually works and the reasons why you may want to look beyond the general duty filters if you really want to clean up your environment.

PAS produces high end HEPA based, fan powered, air filtration systems and has since 1985.  32 years of experience in working with all types of airborne contaminant applications allows them to share their experience and knowledge of this process with anyone who cares to go to their website.

If you have any other questions you can always call the technicians at Pure Air Systems. You can reach them on their toll-free number at: 800-869-8025.

Open Post

An Air Of Superiority

One often considers the term “air of superiority” as a boasting or having an air about oneself that is of conceit for others. As a result this term if often considered  somewhat more negative by most people.

However, there are people and companies that can realistically fit into this “superiority” category without conceit. They have proven themselves to be of a higher caliber with a continued level of high performance exceeding expectations and leaders in their field.

Pure Air Systems, based in Indianapolis, Indiana, is one of those companies. Founded in 1985, PAS has continued to be a leader in the development of high end, commercial grade HEPA based air filtration systems. Beginning with one system in 1985, PAS has developed 6 unique systems ranging from 50 CFM to 2,000 CFM versions. And, in 2015, PAS and LiteWorld developed a new HEPA system designed specifically for providing a prophylactic environment for injections on various parts of the body. The APPAIS unit is a redesign of the HPS portable unit developed in 2006.

In addition, a new system for use as a HEPA Air Curtain will be available toward the end of 2015 and have the ability to create a very effective curtain of low to medium flow HEPA filtered air to act as a barrier to reduce/remove airborne pathogens, allergens and particulate in areas where isolation due to medical conditions are required.

The ability to continue to develop and promote new products that meet the needs of the market is one aspect of Pure Air Systems pedigree. At 30 years of age, PAS has proven itself to be a survivor in a business world where change and competition are a daily occurrence in the new world of high tech business.

For more information on the complete line of filter systems offered by PAS, please go to our website at: or call us on our toll-free number at: 800-869-8025.

Open Post

Phone Books Are Going The Way Of The Dodo Bird!

Many libraries, businesses, schools, medical facilities and even homes no longer rely on the ubiquitous phone book ( white or yellow pages) to get phone numbers and addresses for individuals or businesses. The old yellow pages  line that said ” let your fingers do the walking” has been changed to “let your fingers do the typing.” The use of the computer or digital device has replaced, for the most part, the phone book. Soon, like the Dodo bird, the telephone book, as we know it, will become extinct.

While there is still a portion of the population that either refuses to become computer literate or just can’t figure out how to make anything more complicated than a standard phone work, the vast majority of people use digital devices to not only find individuals and businesses but also to save or “archive” this information for future reference. All with the touch of  a few keys or buttons on your iPhone.

Not only can you find information faster, but you can access rating information on that specific product or service in an instant from a number of respected sources. You can’t do that with a phone book. This is why most companies today put more money, time and serious effort in developing a website and e-mail addresses to provide for a connection to their business from anyone anywhere around the world in less than 2 seconds. You can’t do that with a phone book. Oh yeah….and you can contact the business from your computer and ask them to give you a price or answer more questions about their product or service….without having to call them.

As I mentioned earlier, companies that use their websites as their primary method of marketing their products or services put a lot of time and money into developing a site that is informative, educational, detail specific, includes typical applications and even allows you to purchase their products on line.

Pure Air Systems has been manufacturing and marketing its line of HEPA and Carbon based air filtration systems since 1985. It was one of the first air filter companies to build a website in the early 90’s when .com was not even a term. Over the years PAS has modified, changed, altered and improved its web site to include a lot of useful information including typical applications, specific references showing how other companies utilize the systems and Pure Air University, a section dedicated to inform you on how filtration and carbon adsorption actually works.

You can even order replacement filters and some of the smaller systems online. And of course, there is a section that allows you to send questions directly to the PAS staff so that your specific problem or application can be addressed. For more information on the complete product line please go to our website at:


For more information

Open Post

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:



Open Post