HEPA
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They were originally used in the 1940's for removal of radioactive particles.
HEPA air filtration systems are used to trap very small particles, such as smoke, small bacteria and fine dust.
HEPA systems can be added onto an existing ducted heating/cooling systems.
Portable units such as the Whirlpool Whispure model are also available.
Units that are added to ducted heating/cooling systems are usually by-pass systems (only a portion of the air that travels through the ducted heat/cool system will pass through the HEPA air filtration system).
The reason that by-pass systems are used is HEPA filters can restrict the airflow of the duct system and not only cause damage but will also limit the heating or cooling ability of your system.
We recommend the Dynamic Air Cleaning System for ducted applications beacause of it's ability to filter the entire airflow through the ducts while not affecting heating or cooling performance.
Some companies claim their systems will handle a certain square foot area.
Sizing by square feet can be misleading.
A 200 square foot room with an 16 foot high ceiling will require a larger unit than a room with 8 foot high ceilings.
You really need to know the cubic feet of an area because the fan on an air cleaning device is rated in cubic feet per minute (CFM)
The effectiveness of an air cleaner is also dependant on how many times the air in a room is filtered
This is called air changes per hour (ACH)
The more the better!
A good system will put out 5 to 6 air changes in 1 hour.
Here is a simple formula you can use to be sure of the capacity of a manufucturers offering.
Cubic feet of area divided by hourly airflow of thje system = air changes per hour
Example:
Room size - 12' wide x 25' long x 8' high
System fan - 200 CFM
12' x 25' x 8' = 2400 cubic feet
System airflow - 200 CFM x 60 (minutes/hr) = 12,000 cubic feet per hour
2400 (cubic ft. room area) divided by 12,000 (system hourly airflow) = 5 air changes per hour
Using this formula will show you that some who claim their system will 600 square feet will give you 2 1/2 air changes per hour.
Pro:
HEPA systems are highly effective in removing small particle of airborne contaminants.
Con:
Will not remove harmful
VOC's
(volitale organic compounds), odors, gases, pesticides, viruses, and many bacteria.
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