Re: Filtration

[Guest guest]

Carl made some good points about filters. But there is another consideration.

Whole house filtration is handled by the filter on the furnace/air conditioner.

This filter is almost always placed before the air handler, designed more to

protect the air handler than the building occupants. If designed, installed, and

maintained right, it does both jobs well. However, if inadequate filters have

been used, there is almost certainly a microbe garden on the AC coils and drain

pan, or the furnace humidifier, or on interior insulation of the air handler

chamber. Allergenic/toxic bioaerosols from this source can be blown into the air

stream every time the fan comes on. The system supposedly designed to protect

your comfort and health can become your worst problem.

When I was still working, I developed major coughing problems related to the

workplace HVAC. A brand new HVAC system was installed, and I developed problems

again when the brand new system was only three months old. I could not convince

my employer that the many openings of this large system to measure and balance

air flow had allowed in enough contaminant to cause a problem, and they wouldn't

get it cleaned. But claiming rights under the ADA, I convinced them to install

filtration in the air duct to my work site. It worked quite well, allowing my to

continue working a few more years until early retirement. As Carl stated, a

filter only helps if it filters the air coming from the problem source.

Gil

Filtration - Was: Culturable mold indoor~association w/moisture-rel

Posted by: " Carl E. Grimes " grimes@... grimeshh

Date: Mon Jul 12, 2010 7:33 pm ((PDT))

Barb and others,

Yes, but that is only one reason HEPA and high MERV rated

filters cannot be depended on to solve contamination problems.

Not only for the ultrafine particles but even the ones they are

designed to capture.

1. No filter removes the contamination from its location. It can

only remove that portion of the contamination which is in the air. If

there is mold growing in the crawlspace or attic, for example, no

air filter in the bedroom can clean up the crawlspace or attic.

It's like having a cigar smoker in your house and trying to remove

all the smoke with an air filter. Can't be done because it just

keeps coming and coming. Like Timex watches which just keep

on ticking. Or the Energizer Bunny which keeps on going. Or

Doritos. We'll make more.

_________________________________________________________________

Hotmail has tools for the New Busy. Search, chat and e-mail from your inbox.

http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en\

-US:WM_HMP:042010_1