Variable Speed Drive Motors Power Pure Air Systems HEPA Units

Pure Air Systems was founded in 1985 and at that time the electric motors used in their HEPA based air filtration systems were typical wound motors. These motors were only capable of running either at one speed, or 3 speeds if adjusted to the speed controller. They were also either 120 volt, 60 Hz or 240 volt, 50Hz. 

In 1998, PAS along with General Electric, started to play with the new ECM, variable speed drive motors that were magnet driven and not the typical induction motors used in the past. These new motors could run forwards, backwards and could controlled to run at 1% of power up to 100% of power in 1 percent increments. And, they were rated from 1/3rd HP up to 1 HP using the same base unit but by changing the drive add-on could be changed from 1/3rd HP or 1/2 HP to 3/4 or 1 HP simply by changing the controller section. 

In addition, by using digital controllers, the customers had the ability to change the speed of the motors and the level of filtration from any location in the room or proximate to the filter systems. These units could also be programmed to operate on a pressure differential basis so as to speed up the fan motor when the HEPA filters started to load up and create more static load. This allowed for continuous speeds throughout the life cycle of the HEPA filter.

The newer versions of these motors now allow for complete programing functions either from the factory or by the end user with some minor education by the factory. These newer motors, like the original variable speed drive motors, are now 120/240 50/60Hz so they can easily be adapted to working anywhere in the world. These new motors are used on the complete line of HEPA based air filtration systems offered by PAS. Models, 600HS, 1200HS, 2000HS, and the HPS Portable HEPA filter systems. 

For more information on the complete line of HEPA and Carbon based air filtration systems please go to our website at   or call us on our toll-free number at 800-869-8025.

2000HS Plus S Model - Doors Removed
Inside the 2000HS Plus S Model

Open Post

HEPA Filters

HEPA filters or High Efficient Particulate Air or Absolute filters have been around since the development of the atomic bomb. HEPA media was created in Los Alamos, New Mexico specifically to remove or reduce the alpha particles that were produced in the development of atomic fission. Yes, 1941 was the genesis of HEPA filters that we know today.

This media has the ability to remove a higher percentage of particulate under 0.3 microns than any other type of mechanical media or device on the market today. This is the filter media that is used in all hospital surgery suites, the CDC, optical manufacturing, micro-chip manufacturing and all laboratories both medical and electronic around the world. It is also the main filter used by Pure Air Systems one of the major suppliers of HEPA based, fan powered, high performance air filters in North America.

Based in Indianapolis, IN. PAS has been in business since 1985 and over 32 years has provided the best performing HEPA filtration systems any where. They have incorporated the new variable speed motors that are rated at 120/240 volt, 50/60Hz motors that allow them to be used any where in the world. PAS began with one model, the 600H unit which became the 600HS unit and then moved onto develop the 1200HS, 2000HS and 500HS portable system.

The ability to move filtered air at rates from 50 CFM to 2000 CFM at 1% increments make the Pure Air Systems filtration systems some of the most effective HEPA based air filtration systems on the market. And, over their 32 years of being in business, PAS continues to use the highest quality, made in America, components with over 10,000 units still in operation today.

HEPA filters are difficult to use in air filtration systems as they have a very high resistance and it requires very powerful motors to pull the air through the HEPA filters. Through the use of large industrial fans and motors up to 1 HP, the PAS units produce up to 2000 CFM of HEPA filtered air from their largest models.

For more information on the complete line of HEPA based air filtration please go to our website at: or call us on our toll-free number: 800-869-8025.

Open Post

Variable Speed Control For Filtration

In 1985 when Pure Air Systems was formed, the air filtration industry was using standard induction ( copper wound ) AC motors to run the fans that moved the air across the various types of filter media. Most often these fan powered units used HEPA filters as their primary filtration media.  Since HEPA filters have a fair amount of resistance due to their very dense media design,  motors in the range of 1/3 HP to 3/4 HP and larger were used for these applications. For the most part, these motors were all single speed, 120 volt, 60Hz  AC motors. Using any type of speed reduction controller with induction motors was difficult as the reduction in voltage to reduce speed also increased the heat load on the motor and created a hum or whine sound when dialing down the speed. As a result, most of the systems ran at one speed and one voltage.

In the late 90’s General Electric introduced a variable speed motor referred to as an “electrically commutated motor,” or ECM for short. This motor operates on using magnets rather than copper winding’s and can run forward or backward at any speed from 1% to 100% in 1% increments when controlled with a digital controller. Further more, it was designed to operate at 120/240 volt, 50/60Hz so it could be  used anywhere in the world. This new motor technology provided for variable speed control for filtration systems.

When using the standard induction motors the fan ran at one speed, which was high. This made a fair amount of noise and made it difficult to use it in areas that were occupied or where individuals were sleeping, reading or watching TV. The addition of the ECM motors allowed for use of even larger HEPA based air filtration systems to be used anywhere as the speed of the blower can be reduced so that the sound levels from the fan noise are low enough not to disturb people where the system is being used. Even at low speeds, the filtration efficiency’s are very good so moving air slowly over a long period of time is as effective as moving it at high speeds for short periods of time.

Pure Air Systems has over 6 models of HEPA systems designed to provide filtered air in any environment with a high degree of control. These units can be attached to existing ducted  HVAC systems or as stand-alone units. For more information on the complete line of  HEPA and Carbon based air filtration systems please go to our website at: or contact us on our toll-free number: 800-869-8025.

Open Post

The Cost of Change

It is fairly evident that in today’s competitive business markets that the adapt-or-die approach is fast becoming the norm. While we all like to be able to take some time to adapt to and enjoy new gadgets and technologies that actually make our lives better, the cost to businesses for this continuous evolution of new ideas is significant.

Manufacturing a product that has any significant use of newer technologies is initially expensive in the developmental stages but those costs are usually covered when the product starts selling in large quantities. Over time the R&D costs are adsorbed into the operational side and then profit ensues. This time cycle is normally 1.5 to 3 years and can be longer or shorter depending upon the speed of adaption by the market. However, the cost to most companies is not just the R& D alone, the rapid changes in technological development put a mental and physical strain on employees and management.

Pure Air Systems has been manufacturing HEPA and Carbon based, commercial grade air filtration systems since 1985. PAS started out marketing just one system, the 600H. By 1991 it had three system and by 2002 it was manufacturing six different HEPA based units. The last unit developed by PAS was in 2005/2006. This was the new HPS portable unit that is fast becoming a very popular HEPA system for the commercial market.  The HPS is a good example of how changes in technology make it more difficult today to develop products quickly and inexpensively.

With the exception of the HPS units, all the other PAS systems utilize the newer ECM, variable speed drive 120/240 v, 50/60 Hz motors. The HPS units are standard induction motors rated  120 volt/ 60 Hz. Although it is possible to get them in 220 volt, 50 Hz as this motors are made by EBM out of Germany. The use of this motor eliminated the need for a separate blower system as the EBM models couple the motor with the blower or fan. The induction EFM unit is the only PAS system not using the variable speed drive motors, but the EBM units are very powerful and they are all four-speed motors for air flow adjustment.

Now, PAS is working on another version of the HPS unit to be used in a specific medical injection process. The upside is that we can use all the same component pieces for this new system as are used in the current model. The downside is the housing has to be re-designed and modified to allow a positive flow unit, meaning the motor/blower has to be turned around and the inlet and discharge filters will require special slots for easy insertion and removal.  The controls will be simple, just an on/off switch and speed control switch and a 12 foot long, hospital grade power cord. Unlike the other PAS units, this new HPS version will be fabricated from aluminum to reduce the weight and it will be painted white rather than the standard beige paint now used for all the units.

The cost of making this re-designed version of the HPS system comes in two flavors, dollars for the engineering and fabrication of one unit ( prototype) and time and energy spent both finding and working with companies that can reverse engineer and re-design the system all at one time. While the market potential for this unit is big, there is no guarantee this system will fly off the shelves. It may take a year or longer for the market needs to identify the systems capabilities. It is, however, the cost of doing business in this highly competitive and technologically adaptive market.

For more information on the complete line of HEPA and Carbon based air filtration systems please go to our website at: or follow us on Twitter @pureairsystems. Of course you can always call us on out toll-free number at: 800-869-8025.

Open Post


You sit down with a potential customer that has been evaluating your product or service for the past two months and is still hesitant to make a commitment to you one way or the other. You tell him again, for the twentieth time, that your product or service will meet all his needs and more. He looks at you and says those three dreaded words very rapidly so as to make it sound like one word….”Iknowbut.”

If you think about it, you probably either use or hear this term used 10 to 20 times per day. For example. One of your teen children ask to go to a party at a place where you know there will be older kids. You tell them no they can’t go and they say  all their friends are going. You say, Iknowbut that doesn’t mean you can go. Or its a sunny day and you want to play golf but you also promised your wife to do some house repairs. You plead your case and she says to you, Iknowbut you told me the same story last week.

How is it that these three words can have so much power? The term literally diffuses a line of reasoning or logical progression of presentation. And, perhaps the reason for that is we all use it some much ourselves that it weakens our resolve to make our point.

In the business world closing orders and getting people to commit to a decision has never been more important. Changes in financial directions, technology and personnel are happening every day and affecting operations of small and large firms alike. This being said, it is even more likely that someone will use these facts when they pull out the Iknowbut term. As in, Iknowbut we can’t afford to put this product in our system now when we don’t even know if we will need to make major changes in the next six months.  Frustrating.

Pure Air Systems has been manufacturing commercial grade HEPA and Carbon based fan powered air filtration systems since 1985. These systems have been used in almost any type of  commercial, institutional, residential and industrial application you can think of. The term “performance” is synonyms with Pure Air Systems products. These rugged, well-designed metal housed units incorporate the latest in ECM motor design and digital control systems allowing them to be used anywhere in the world. Only commercial grade, certified, 99.99% at 0.3 micron filters are used in the systems. These are complimented by high grain load carbon media and polyester dual-layer prefilters.

Interesting that at Pure Air Systems we often hear comments from customers who are trying different filtration options for a specific problem and we hear comments from engineers and operation people on how they sold the idea of using a PAS system with Iknowbut.  Someone would say why purchase the PAS unit when we have these other filters in stock. The response is, Iknowbut we have tried everything and nothing compares to the performance of these systems.

For more information on the complete line of HEPA and Carbon based air filtration systems you can find us at: or on Twitter, @pureairsystems or on our Facebook page. Of course you can always call us on our toll-free number; 800-869-8025.

Open Post

Extra Virgin Olive Oil

There are times when you really see something for the first time after seeing it over a 1,000 times. You know what I mean. We are blasted by the media with all types of  new terms now common or strange terms now common. Our acceptance of odd terms and crazy  advertising slogans is amazing. We seldom question these terms because we start using them ourselves. The title of this blog is one of them.

So…when can virgin be extra virgin? Can you be extra dead? Things can be extra special, although special is usually good enough for me. I suppose the term extra denotes that something is better than what you can imagine. Again, if I can’t imagine it, how can it be better? Quite the conundrum. Hm..can you have an extra conundrum?… Get the point.

Companies have a habit of trying to out-do their competition by using the word extra to describe how well their product cleans, or the amount of additional service you’ll get by choosing their company or my favorite….NO EXTRA CHARGE.  Which actually means we are over-charging you for the base service but throwing in some other services that we would normally charge for but you think are free when they really aren’t.

Pure Air Systems has been manufacturing commercial grade, certified HEPA based air filtration systems since 1985.  From the beginning the metal framed, high performance HEPA and Carbon based systems were designed for commercial, institutional and industrial applications and have exceeded the performance requirements by our customers.

Using ECM style, digitally controlled motors, that are rated 120/240 volt, 50/60Hz, these systems can and are used around the world in applications as simple as food storage pressurization to portable and stationary surgery suites in second and third world countries.  The ability to use motors up to 1 hp but operate on the electrical usage of a 1/3 hp motor which makes these units inexpensive to operate and maintain.

The PAS HEPA systems range in volume capacity, as measured in cubic feet per minute, from under 50 CFM to 2000 cfm. The variable speed controllers available on all units allow for incremental air volume adjustments in 1% increments to allow for finite control of the HEPA filtered air required for your applications. There are few commercial grade HEPA systems on the market that give you this type of control with a full range of systems.

The new HPS 350 and HPS 500 portable units are fast becoming one of the more popular HEPA units available from Pure Air Systems. These compact, yet powerful, HEPA units have four speed volume control and are only 21 inches long and 13 inches square. They weigh less than 24 lbs.  These new systems can be used stand-alone or even configured in a by-pass mode for use with existing HVAC systems.

For more information on the complete line of HEPA units and their applications, please go to our website at; You can also follow us on Twitter @pureairsystems or follow us on our Facebook page at: Of course you can always call us on our toll-free number. 800-869-8025..which by the way is at no extra charge…


Open Post

Cutting Electrical Costs Using ECM Motors

Everyone who owns a home knows that the costs of home ownership go well beyond just paying the mortgage, insurance and taxes. It also includes the cost of heating and cooling the home; which can be significant.

One of the major uses of electricity is the electrical motor that turns the fan in the forced air heating/cooling system found in most homes. The motors range in horsepower from 1/3 to 3/4 HP and many of them are the standard induction motors. These motors use a lot of electricity and are relatively inefficient; often running 12 to 24 hours per day especially in the hottest and coldest months of the year.

Depending upon the electrical costs in your area; usually measured in costs per kilowatt hour, your overall electrical costs to run your home may range from as low as $50.00 per month to upwards of $300.00 per month or more for larger homes. Interestingly almost 40% to 50% of these costs may come from running the heating/cooling fan motors.

Since the early 2000’s the ECM motors or Electrically Commutated Motors were introduced ( BY GE). Unlike standard induction motors that use windings and have only two to three speeds available, the ECM motors use a series of magnets to turn the motor shaft and have a speed range that runs from less than 10% to 100% of available power ….and this can be digitally controlled in 1% increments so you have a very wide range of speeds to run the motor.

Not  only does this variable speed capability allow for better air flow control for your heating/cooling fan but is also uses up to 50% less electricity than the standard induction motors running at the same horsepower.

Pure Air Systems was the first HEPA based air filtration company to introduce these motors as the main motor drive unit for the complete line of fan powered, commercial grade, certified HEPA systems.  In fact, PAS introduced the GE ECM motor drive systems in 1999, almost 3 years before these motors were introduced into the HVAC systems. Today, the ECM motors are ubiquitous in the heating/cooling and appliance industries.

Aside from their variable speed and low power consumption capabilities, they are also capable of being programed for a variety of applications. For the HEPA units these motors are capable of automatically ramping up when the pressure drop across the HEPA filter starts to increase and thus maintaining the same air volume throughout the life of the HEPA filters.

When the HEPA units are used in conjunction with a heating/cooling system also using the ECM motors, you have the best of both worlds.

For more information on the Pure Air Systems ECM driven HEPA systems please go to our website at: www.pureairsystems. com

Open Post

Better Heating/Cooling Systems Aid In Filtration

When it comes to heating or cooling the interior of their homes, most homeowners assume most heating/cooling systems are more than adequate to achieve comfortable room temperatures; be it summer or winter. Nothing could be further from the truth.

Most homes in the US use split system, forced air, ducted heating/cooling unit that consists of a compressor unit ( located outside) that is used for cooling the house but may also be a heat pump version that can provide cool or hot air. The other part of the system is the air handler (fan powered unit) normally located inside the home in the basement, attic, garage or crawl space.

HVAC systems are rated by using a SEER standard (most now minimum 12 SEER) with units now having efficiency ratings up to 21 SEER. And, many of the newer heating/cooling systems incorporate the variable speed, computer controlled digital motors for air flow. These newer units are not only much more energy efficient but can also significantly aid in air filtration and the removal of indoor airborne contaminants.

The new variable speed fan systems in the air handlers allow for the fan motor to run continuously using very little electricity. When the system calls for heat or cooling the fan motor ramps up to meet the air flow requirements and runs at that speed until the heating or cooling demand is met. Once the thermostat is satisfied the house is at the desired temperature the fan slows down to a very low running speed (around 30% of high speed).

Beyond the fact that using a constant running fan keeps the air temperature more even throughout the house, the constant movement of air also keeps the particulate in the house airborne and allows them to be continuously pulled back to the air handler ( and air filter) through the return air ducts.

This is important because unless the air in the home is constantly being moved and pulled through the HVAC duct system, the dust, dirt, dust mites, mold and bacteria will stay on the floors and other surfaces and unless they are disturbed and put back into the air, they will not be captured by the air filters in the air handler.

Pure Air Systems has been using the variable speed digitally controlled motors in their Hepa Shield systems since 1999. And, is the only HEPA filtration system manufacturer in North America that uses this technology. When coupling the HS series HEPA units to a variable speed heating/cooling system you have the best of both worlds. A commercial grade HEPA system that runs in conjunction with the variable speed HVAC unit, ramping up and ramping down and providing constant air filtration with minimal energy costs.

For more information on the variable speed heating/cooling systems and the line of variable speed HEPA systems go to our website at:


Open Post