Opinions - HEPA, electrostatic, ionizer

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Old 09-29-03, 01:07 PM
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Opinions - HEPA, electrostatic, ionizer

We have a central furnace/AC with an electrostatic filter setup. My wife suffers from allergies, so we're trying to find some solutions to air cleaning. I'm looking for thoughts on the 3 big filtering systems as mentioned in the subject. What I've found so far is:

- A Sharper Image ionizer placed in the bedroom does help at night. But another website pointed to many problems with ionizers - namely that they produce way more ions than exist in nature and this could be harmful. That site also said it could dirty up the walls even with the filtration system since the filter could only pull in air close to it.

- A HEPA portable filter may work, but of course these are typically noisy and expensive to operate. And we'd need many in the house to keep it all cleaned.

- A HEPA filter in the furnace would work for the whole house, but I don't know if there are any that can just replace the mesh filter that comes with electrostatic units. Plus I believe HEPA requires a strong fan because of significant pressure drop across the filter - don't know if the house furnace is up to it.

Any thoughts? Thanks in advance...
 
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Old 09-29-03, 02:19 PM
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FILTERS

You could look up at PUROLATOR filters they have lots of them . They have a high capacity 2000 cfm HEPA filter .There is the air bear it will work at the 2000 cfm 90%to 93% dust retention. Then Honeywell has there whole house air cleaner trap. there is a lot to look at ED
 
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Old 09-30-03, 07:09 AM
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Thanks for the tips - I'll look them up! So are you saying that the Purolator filter or Honeywell trap are meant to use with an electrostatic setup? Or at least, that I can find the right size for my electrostatic setup even if I have to turn off the electrostatic unit? Because most HEPA house filters I've seen are meant to replace the basic drop-in filters. I haven't seen them that are sized for electrostatic units.
 
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Old 09-30-03, 07:12 AM
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Thumbs up 4" media filter

I have gone with a 4" media filter on my central HVAC system, it works great and the replacement filters are less than $10 when purchsed by the case.
 
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Old 09-30-03, 11:29 AM
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I'm not sure I understand clearly what you have now, but if you have an electrostatic filter on your central air handler (electronic unit on the main air return, large metal cell that needs to be washed periodically...), you already have about the best air filtration you can get. I wouldn't add anything that might restrict any air flow or you will decrease air through the electrostatic plates, thereby decreasing their effectiveness. If you would like additional filtration, you might add a portable HEPA unit that can be moved from place to place as needed. Not all are noisy or expensive to run.

Ionizers are potentially more harmful than beneficial and they do often cause dirt to be attracted to surfaces around them. Testing seems to have found the benefits of them to be more psychological than physical.

Doug M
 
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Old 09-30-03, 11:36 AM
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There was a great comparison article on air cleaners in Consumer Reports a month or two ago. You might want to check it out.
 
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Old 09-30-03, 11:53 AM
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Filters

I find just the other way .We take out more and more of the electronic air cleaners or fliters. People dont keep them washed or clean so they dont work as they should.They have the cells cut down in size so they fit in the dishwasher now. But people still dont keep them clean ED
 
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Old 09-30-03, 04:58 PM
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Originally posted by dougm
I'm not sure I understand clearly what you have now, but if you have an electrostatic filter on your central air handler (electronic unit on the main air return, large metal cell that needs to be washed periodically...), you already have about the best air filtration you can get. I wouldn't add anything that might restrict any air flow or you will decrease air through the electrostatic plates, thereby decreasing their effectiveness. If you would like additional filtration, you might add a portable HEPA unit that can be moved from place to place as needed. Not all are noisy or expensive to run.

Ionizers are potentially more harmful than beneficial and they do often cause dirt to be attracted to surfaces around them. Testing seems to have found the benefits of them to be more psychological than physical.

Doug M
Yes, currently we have a working eledtrostatic filter which I DO keep clean. However, as Ed pointed out above, I'm hearing that they're not as good as people first thought they were. And I too have read that ionizers could cause more harm which makes me want to avoid those.

Yesterday I did buy a portable HEPA filter, but I thought if I could somehow replace the filters in the electrostatic unit with HEPA ones, would I get the benefit of the whole house being better filtered? I wasn't thinking of using the HEPA filter in conjunction with the electrostatic unless someone made a product specifically like that. I was thinking of turning off the electrostatic feature and sticking with only a pass-through filter.

54regcab: Were these filters meant to be used with a basic filtration unit? I'm guessing I can't use something like that unless the cells be able to replace the electrostatic cells.
 
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Old 09-30-03, 09:08 PM
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Lightbulb Electronics air cleaners

If you already have an electronic HVAC filter the 4" won't help you.
However as Ed says the electronics ones are rarely maintained properly and are often repalced with media filters.
The 4" was a cheap solution for us, the air filter housing was easily modified to accept 4" media.
 
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Old 09-30-03, 11:39 PM
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Ok, I want to make sure we're on the same track.. you said you have an eledtrostatic filter.

or do you have an Electronic Air Cleanr?


Really, the eledtrostatic fitler is the thin 1" filter that take place of the regular throw away filter..

Electronic air cleaner is the one w/ the cells..

I don't suggest either of those units.. I had the eledtrostatic filter, and over time, the dirt gets imbedded in the fiber, and it don't get clean..

Electronic air cleaner are a pain to clean! and don't do that well when they get dirty.. the 4" filter are better, and i too taken out the cells for other people, and replace it w/ the 4" filters.
 
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Old 10-01-03, 11:00 AM
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I would trash the electronic and go with the airbear.
 
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Old 10-02-03, 09:42 PM
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Originally posted by Jay11J
Ok, I want to make sure we're on the same track.. you said you have an eledtrostatic filter.

or do you have an Electronic Air Cleanr?


Really, the eledtrostatic fitler is the thin 1" filter that take place of the regular throw away filter..

Electronic air cleaner is the one w/ the cells..

I don't suggest either of those units.. I had the eledtrostatic filter, and over time, the dirt gets imbedded in the fiber, and it don't get clean..

Electronic air cleaner are a pain to clean! and don't do that well when they get dirty.. the 4" filter are better, and i too taken out the cells for other people, and replace it w/ the 4" filters.
I didn't even realize they were different. I think we have an electronic air cleaner. Essentially, the raw air first goes through a metal mesh screen about 1/3" thick. Then it passes through a set of vanes which are electrically charged. The unit with these vanes is maybe 4" thick. It has a test button which crackles when you press it.

Originally posted by Mattison
I would trash the electronic and go with the airbear.
By trash, do you mean remove the entire assembly - housing and all? Or just find a way to fit the airbear into it and seal the edges - relying solely on the airbear?
 
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Old 10-03-03, 08:42 AM
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Filter

--------------------------------------------------------------------------------
Originally posted by Mattison
I would trash the electronic and go with the airbear.
--------------------------------------------------------------------------------
Im with Matt all the way.Try and use the housing as is or rework it for the AIR Bear filter. The filter size is 20"X25"X5".

like I said before I have taken more of the Electric one's out than I have put in. ED
 
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Old 10-03-03, 01:50 PM
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Electronics cleaners

Yeah I had one in my last house, what a waste of $$$
Granted it did work good after a fresh cleaning but what a pain !!
Installing a 4" filter box at the time of installations isn't much harder than a standard 1" box, i dont know why 4" hasn't become standard.
Not to mention equiptment stay MUCH cleaner than with 1" filters
 
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Old 10-03-03, 07:24 PM
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All of these discussions of the different filtering media are great. The only problem with this is THEY DON'T FILTER ALL THE AIR IN THE HOUSE, as many people think they do. Therefore they're not likely to solve NickC's problem.

If they air return was "changing" all the air in the house, you'd never have to dust. To prove this to yourself turn your system on and take anything really light, a feather, a pinch of flour, etc. Standing right in front of your return toss it into the air and watch as it's drawn to the (return air) grill. Now move 5' away and repeat the experiment. Probably NO movement toward the return air register. Now move 10' away. You get the picture. It's returning air to the central system, NOT filtering all the air in the house.

I know I didn't help with your allergy problem but might have saved you (or others) some time and money.

Frank
 
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Old 10-07-03, 05:39 PM
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Good point. I was hoping the furnace filters would clean the air entering the house from the outside. This air, assuming it's full of allergens, would then get cleaned and blow into the house as filtered air. Are you saying that these filters won't do the trick?
 
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Old 10-07-03, 06:24 PM
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I disagree w/ Frank in some way..

Yes, the heavy stuff is going to fall on to the floor and furnature.. but the light stuff that floats is going to get cleaned by the filter..

If you have a good design system, with good air change (supply and return) the air will be filtred out.


I know there is a diffreance.. When I had one house the furane used the cheap fiberglass, the place was always dusty.. I upgraded to the better filter, adn the place was abit cleaner.. Yes you still need to dust and vaccume the house no matter what.. it WILL help people with allgergy.. I am one of them..
 
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Old 10-08-03, 11:08 AM
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air change

Id say it get's all the air in a home . I'm with Jay here. Put a big
very good humidifier in a home one time Two week later they called up come look at the home. There was not a place in the home that didnt have a white dust on it . It was lime and calcium from the humidifier. The guys had put it on the hard water line and we do have hard water here. So thats like the flour it didnt get back to the filter.
Also find that the more a person works to keep a home clean. The more dust is in the air all the time and the dirtier the air filter they have will be.
On most jobs the outlets are near the outside walls and the return in the center of the home. So all the air should get to the air filter sometime. There also are filter set ups to bring in the outside air if you want to go that way ED

My .02 cents
 
 

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