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Filter Tips
True or False? You should change the filter in your central heating
and-or air-conditioning system at least four times a year? If you
answered true, you probably are enjoying fresher, cleaner air than
your neighbors.
For persons with allergies it is wise to clean or change most
filters at least once a month when pollen is prevalent and twice a
month the rest of the year. There are other reasons to clean or
change your forced-air unit filter more often. A few examples:
1) if you live in a sandy community near a beach or in the desert
2) if you live close to a major roadway
3) if you are near a construction project in progress.
We all have a pretty good idea why filters are important. They clean
whatever it is they are designed to filter. Oil filters clean oil
and water filters clean water. But,
furnace filters don't clean furnaces. Instead, they clean the
air that is heated or cooled, and then distributed by the furnace.
Because it is not called an "air" filter some think that it filters
debris to protect furnace parts instead of the air that we breathe.
When shopping for a filter it is a good idea to know a little bit
about a measurement called the micron. A micron is 1/1000th of a
millimeter. Many pollens and spores are only a few microns in size
and therefore are very difficult to filter. To effectively filter
such small particles the size of the holes in the filter would have
to be so small that air would have difficulty getting through. This
would affect the ability of the system to move air freely.
To allow reasonably free air movement while filtering microscopic
particles, electrostatic filtration is used. The particles are fed
through a mesh that electrically charges them. The charged particles
are then sent through another filter that contains the opposite
charge. Since opposite charges attract each other, the charged
particles are drawn to and adhere to the second layer of filtration
material. We aren't sure whether this should be called filtration or
magnetism. In any event, this is how minute particles are removed
from the air in a central heating or cooling system.
Some filters use electricity to create the magnetic field and others
use static electricity. The types that use conventional electricity
are permanent, and once installed are only removed for cleaning. The
mesh in a permanent filter is made of metal, and with proper use,
literally will last a lifetime.
The filters that rely on static electricity are constructed from
polyester, a plastic-like substance. If they are cleaned every month
they will last for several years. Considering purchase and operating
costs we suggest the latter as a first line of defense. If the
polyester filter doesn't do the job well enough to solve a special
allergy problem then we would recommend the electrically operated
permanent type.
And remember, as a filter in a central system begins to clog up it
produces increased back pressure on the blower motor. Left
unattended a dirty filter actually can shorten the life of the motor
an expensive item compared to the cost of a filter.
If you are interested in more, please
check out our
Clearview Service Agreement,
and you won't have to worry about at thing. |
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