This should be an easy one.. I already have an opinion on this but
would like to hear more as I could be wrong (not being a air flow
expert and stuff).
When deciding between going with an electronic filter vs filter media
(assuming cost isn't an issue) which would be better. I've seen how
electronic filters are built and I would think that they provide less
restriction. However, I've been told the opposite - that filter media
provides less restriction than electronic filters... Is that true?
I have a a HVAC Company, I would not suggest installing a Electronic
Air cleaner, besides the cost of the cleaner and installing then they
seem to break down alot, and a contractor can not fix them they have to
take them to a speclist to have them fix, but they do have lest air
restriction, I perfer for my customers to use 3m pleated filters they
are high destisy but they are good filters and they do have to be
change once a month, Or Use a good eletrostatic filters Newtron have
been around a while, Or if you really want a hosptital grade Abatement
tech. have some but cost can run 600-1200 depending on who installs it.
you would have to be crazy to buy an electronic filter. I pulled mine and
use a pleated filter instead.
Not only are they difficult to clean and expensive, but expensive to fix.
Of course it is also a matter of your house. My old house had two HVAC
systems because of an addition. The electronic filter on the first floor
had to be cleaned every few weeks. The one on the second floor could go
Not sure which type you had, but most are extremely easy to clean. You
pull the collector grids and either hose them down outside, or just run
them through the dishwasher. Super easy, just have to make sure they are
dried completely before putting them back.
As for fixing, there is little to fix on one. It's just a HV power
supply and a collection grid. Considering the power supply is little
different than a neon sign transformer and those last decades without
failures there is little reason that a quality EP unit should ever need
service in any reasonable lifetime.
Total system run time and the cleanliness of the environment will affect
the cleaning frequency. Newer addition likely means better insulation
and shorter HVAC run times. Sizing of the system and efficiency also
would affect run time.
In the middle of a new england winter, hosing them down outside is not
realistic. Putting them thorugh the dishwasher works, but only one wil
fit in ours at a time, and there are two of them, so you have to run
two cycles through the dishwasher. After two cycles you have to wait
for the second one to dry. Not difficult, I agree, but annoying, and
while you're doing this you are running the furnace without an air
I had a Honeywell electronic air cleaner, dates from about 1987. It
has a little sensor that detects air flow in the furnace output. That
way the air cleaner turns itself on and off without tieing into the
furnace fan circuit. When that detector board failed, all you could
do was replace it -- for a cost of $500.
I can get good pleated filters that fit in the Honeywell air cleaner
"slot", and that's what I use now. Changing them once a year takes
about 1 minute.
Another disadvantage of electronic air cleaners is the "snapping"
noise that they make when they run. If you have a bedroom right over
the furnace, you can hear this and it's pretty annoying.
Perhaps an earlier design unit, the newer ones seem to be designed to
fit the dishwasher ok. A rinse in the bathtub or laundry sink is also an
When the grids are out for cleaning you should never be operating
without a filter, there should always be a basic media type pre filter
in the system. An EP is not a replacement for that pre filter.
A poor design. An airflow paddle switch, a differential pressure switch
or a sense line to the fan circuit would all be better. There is also
minimal reason not to just leave the unit powered full time as they
consume little power.
Filters should be changed more than once a year unless you're in a
climate with minimal heating and cooling requirements and you indicated
new england which has substantial HVAC requirements.
That snapping should be almost non existent if you have a proper pre
filter before the EP. An EP does not "snap" in normal operation, it only
snaps when a large piece of debris bridges the collection grids and
debris that large would never make it past a proper pre filter. It
sounds like your system was not properly configured.
Odd, I'm not an expert either, but I have some experience with a couple
air handlers with EPs at a place I used to work. They were moderate
sized Carrier units, not really larger than you would have serving a
home since they were serving a couple thousand sq. ft. of office area. I
don't recall hearing much snapping ever, and they were doing their job
as the grids would buildup a good load of crud.
Electrostatic precipitators aka electronic filters will almost certainly
have lower airflow resistance than a media type filter, however you
should to have a conventional media type pre filter anyway though it
doesn't need to be a fancy high efficiency one. The pre filter will
remove larger things like a hair perhaps that could short out the
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