Blog Tag: static pressure

Using HEPA filtration systems as air moving boosters is fairly common and in most cases necessary. If you have a multiple number of pick up points from which you want to remove contaminated air you need to understand the concept of air flow resistance or pressure drop.

When moving air through any type of duct system you have to take into consideration the resistance of air flow through the duct especially if it is flexible duct and you have some 45 degree and 90 degree bends. Air flow resistance is measured in inches and the higher the number the greater the resistance the larger the horsepower has to be on the motor/blower system that is moving that air from one point to another.

If you have any type of air filtration device in the air flow system that being used to remove the contaminants you also have to take into account the static pressure loss across that filter as well. If it is a HEPA filter you have a significant pressure drop which needs to be added into the total line loss when designing the blower/motor system.

Pure Air Systems has been making fan powered HEPA based air filtration systems since 1985. They use variable speed drive ECM motors on all their systems that adjust automatically by speeding up as the pressure drop across the HEPA filter increases.

Since Pure Air Systems makes HEPA filtration systems that are fan powered they can be used as boosters for moving air through an entire ducted system to maintain the proper carrying velocities through the ductwork even as the HEPA filters load up.

It takes a lot of power to move air through ductwork and a filter so using the PAS systems makes sense. The models range from 600 CFM to 2000 CFM air flow capability using 1/3, 3/4 or 1 HP ECM motors. PAS is one of the few companies in the world that make high end, fan powered, commercial grade HEPA air filtration systems that can be used as stand-alone systems or in conjunction with a ducted HVAC system or commercial air handlers.

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

Almost every home in the US is heated and/or cooled using a forced air ducted ventilation system attached to a heating/cooling system. The vast majority of these systems are designed to move a certain amount of CFM of air to adequately heat or cool the living spaces. In addition, many of these systems incorporate some type of air filtration device; either a pleated or box style filter or a more  sophisticated high efficiency air filtration system. In either case these filtering devices can reduce the air flow through the ducted ventilation system.

All HVAC systems are designed to move a certain amount of air, as measured in cubic feet per minute or CFM at a certain resistance or static pressure, as measured in inches of water using a fan motor with enough horse power to move the warm or cold air through the duct work an into the living spaces. Unfortunately, most HVAC systems do not take into account the resistance across the air filter or filtration device and this added static pressure can reduce the air flow through the system thus taking longer to heat or cool the living spaces. This both increases the operational costs as well as providing for a less than comfortable environment.

Pure Air Systems manufactures a line of HEPA and Carbon commercial grade, high performance air filtration systems that are designed to attach to the return air side of any forced air ducted heating /cooling system. These fan powered units are designed to assist the heating/cooling fan system but taking up any additional static pressure across the HEPA and Carbon media so the HVAC fan only sees the static resistance from the duct work. This allows the HVAC system to operate as designed and heat and cool the house effectively and efficiently.

Pure Air Systems is one of only a few companies that provide fan powered units and it is the only air filtration company that uses the ECM, digitally controlled motors that can run in sync with the ECM motors now used in all the new HVAC systems. In addition the Pure Air Systems units can be used as stand alone systems and move HEPA filtered air throughout any living environment without being attached to an HVAC system. This is very important for those environments where a non-ducted heating cooling system is utilized.

It is important to be aware of these issues since you want to get the best performance and lowest operating costs from your new high efficiency heating/cooling systems.

For more information on the PAS line of filtration systems please go to our website at www.pureairsystems.com.

No matter what type of forced air heating/cooling system you use, all of them require an  air filter of some kind.  While many people believe the primary purpose of the filter is to remove airborne dirt and dust particles to keep the home or office environment cleaner, the fact is the filters  are used primarily to keep the heating/cooling system clean.

All split system HVAC units have a cooling coil for AC and sets of burners for heating located in the main air handler. It is necessary to keep the cooling coils and burners clean and free of dust and dirt or they will not operate properly and become very inefficient. In addition, the air filter is needed to keep the blower wheel ( the device that moves the air) from getting dirty and out of balance. Also the furnace fan and motor are designed to move the air through the system and compensate only for the static pressure or resistance for only these components. The filter can not add much static load to the fan.

It is for these parameters that most furnace air filters are designed and that is why the majority fall under one of two categories; “crappy” and “almost useless”. Yes, they can remove enough of the larger dust and dirt particles to keep the coil and burners clean but No, they are not dense enough to remove the smaller more harmful airborne particles. Making the filters too dense adds too much static load to the HVAC motor and significantly reduces the air flow and this means you heat or cool longer to obtain the desired room air temperature.

While there are a large number of expensive electronic, hybrid electronic or other media type filters available for use with you HVAC unit, for those of you who want to continue to use a simple, inexpensive, throw-away media filter for your furnace there is a better choice.

Pure Air Systems offers a dual-layer, polyester, ring panel filter that is commercial grade and fits tightly in the filter frame, holds a large amount of dust and dirt, collects particles as small as 3 microns and adds very little resistance or static pressure to the HVAC  blower/motor assembly.  These filters are easy to change and have an unlimited shelf life.

In addition, Pure Air Systems offers a line of filters using the same ring panel design with polyester media on one side and carbon media on the other side. These filters are great for both removing airborne particulate as well as odors and gases.

For more information on these filters and the other filter systems offered by Pure Air Systems go to our website at: www.pureairsystems.com