Reading some of the advertisements for
electrostatic air filters you'd think that they
would be the perfect choice. But there's more to it.
An
electrostatic air filter collects particles by the
idea that the filter is charged one way and the dust
particles are charged the other way, causing the
dust particles to stick to it.
In practice this works well. The problems is when
the surfaces of the electrostatic air filter are
covered in dust. New dust now coming through the
filter doesn't stick that well to the filter. Still,
you can pull out the filter, wash it off and now
it's back in business attracting dust.
The time it takes an electrostatic filter to become
nearly useless can be very short, as soon as a
couple of weeks or it might last a month or so. It
all depends on where you live. If you purchase an
electrostatic air filter you should check it every
week until you get an idea of how often yours needs
to be washed.
The major con of electrostatic air filters is
forgetting to wash it in a timely manner. This
causes the system and ducts to get covered in dust
etc. This can stress the components causing early
failure, increase allergies for those affected and
cause dirt to blow out of your vents.
Which type of filter should I use?
The safe answer to that is "The one the
manufacture of your HVAC system tells you to use".
The problem with this is that typically, HVAC system
filters are not there for your comfort, they are
there to keep dirt/dust off system components so
they don't fail - not to provide you with highly
filtered air. For people with allergies, getting
your system cleaned regularly is a must - it
improves the air quality, enhances the life of your
system and reduces energy bills.
Electrostatic air filters usually do better at
filtering particles than the manufactures
recommended filter but only if you wash it
regularly, if not, then it will be worse.
By the time you remember to wash the filter the
system may be contaminated and require cleaning.
Pleated filters are our preference because they
typically provide better filtration and only need to
be changed every 4 to 6 months depending where you
live. The down side to this over the electrostatic
filters is you have to buy a new one each time.
Pleated and manufactures recommended filters have
another con, when they get dirty they restrict the
air flow more and more (but at least they are
keeping dirt out of the system). So getting a fresh
filter in there on schedule will increase air flow
and reduce your energy bill.
Pros
Cons
Electrostatic Filters
Good
filtration, Good air flow
Higher
maintenance. Failure to maintain can result
in a system dirtied quickly, increased
allergies and dirt coming out of duct work.
Higher initial cost.
Manufactures Suggested Filter
The
system was designed to use that filter.
Cheap
Not a high level
of filtration (which maybe important to
allergy sufferers). Have to keep buying
replacements.
Restricts air flow as they get dirtier,
increasing energy bills.
Pleated Filters
High
level of filtration
Have to keep
buying replacement. Restricts air flow as
they get dirtier, increasing energy bills.
Cost it between the above two.
Warning!
There are some filters on the market that promise
near HEPA (High-efficiency
particulate air) filtration.
The perfect solution for allergy sufferers?
Yes BUT they typically restrict the air flow so much
that the system can't cool or heat correctly. Talk
to your Air Conditioning Contractor before
installing one of these.
Summary:
Which ever filter you go with, put a
"reoccurring" calendar entry in your favorite
calendar software to replace or wash your filters
and do it when it tells you to.
This will give you better air quality, save you
money and extend the life of your system.
Get your system cleaned every 5 years to get rid
of everything your filters missed over the years -
it builds up. (varies on location 3 - 7 years).
An
electrostatic air filter collects particles by the
idea that the filter is charged one way and the dust
particles are charged the other way, causing the
dust particles to stick to it.
