Re: Filtration - [Was: Culturable mold indoor~association w/moisture-related pro...]

[Guest guest]

Carl,

Thank you for your comprehensive post on filtration. I am saving this for

reference.

Connie Morbach

>

> 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.

> Filters may help to reduce, but they don't remove the cause of the

> contamination. The cigar smoker has to be removed and then the

> filter will help to gradually reduce the smoke.

>

> 2. It can only remove the contamination from air that actually

> goes through the filter. Most air does not. It stays on the other

> side of the room. Or in the other room, or attic, or crawlspace.

> Behind the cabinets. Under the carpet.

>

> 3. A HEPA or high MERV filter only removes particles, not

> chemicals or odors or molecules. These are hundreds of times

> smaller than the pores in the filter. They go right through like sand

> through screen wire. They have to. Because they are the same

> approximate size as air molecules and the air must go through

> the filter. If it can't then the particles can't be separated from the

> air and captured on the filter. Different methods are needed for

> molecules of chemicals and odors.

>

> 4. A HEPA or high MERV filter is limited, as Dr Thrasher clearly

> stated, to particles 0.3 microns and larger. It used to be thought

> that only a few percent were smaller than 0.3 microns. It is now

> known, because there are instruments to measure smaller

> particles, that 90% may be smaller! Those are the ultra fine

> particles Dr Thrasher is discussing. They go deeper into the

> lungs, tend to stay longer, and beginning acting like chemicals

> rather than just particles.

>

> 5. A HEPA filter has a MERV rating of 17. As most of you know,

> Jeff May recommends MERV 11 for air conditioners. The reason

> he doesn't want a higher MERV rating is the higher the rating the

> smaller the pores in the filter, restricting air flow. If you don't get

> enough air flow air conditioners can freeze and motors can burn

> out. MERV 11 is a good balance between particle removal and air

> flow.

>

> 6. A HEPA filter has a very specific definition. It must capture

> 99.97% of particles at 0.3 microns. Smaller ones get through.

>

> What's the 0.03% that isn't stopped? Can't be much, right? It

> means that if 10,000 particles go through the HEPA filter 3 will

> escape. Consider that typical air has 30,000 to 300,000 particles

> in every cubic foot of air. That means 9 to 90 are not stopped by

> the HEPA. Still, no big deal except many of you react at those

> extremely low levels.

>

> But that's not the whole story of exposure. If the filter is rated at

> 100 cubic feet of air per minute then 900 to 9,000 particles are

> not stopped - every minute! Because there are 60 minutes in an

> hour, that calculates to 54,000 to 540,000 each and every hour.

>

> 7. Finally, and here is the latest " kicker " on HEPA filters. The

> HEPA filter is what goes inside a box with a motor. That box is a

> HEPA " device " which contains the HEPA " filter. " The filter, not the

> device, is rated at 99.97% at 0.3 microns. The device may or may

> not perform at the same level as the filter itself, especially if the

> filter doesn't fit tightly and correctly inside the box. Which most

> don't.

>

> An ANSI standard is being written to measure the effectiveness

> of HEPA " devices. " Preliminary testing is showing that about 20%

> of industrial grade HEPA devices fail. Many miserably. Almost

> none of the industrial HEPA filtered vacuums pass. (Most home

> units have not been tested but the ones that have are generally

> not made as well as the industrial ones and perform worse).

>

> Because of the high air resistance of the HEPA filter much of the

> air finds an easier pathway around the edges, not going through

> the filter at all. It isn't filtered at any level for any particle size!

>

> Which means item " 2. " above should be changed to read, " It can

> only remove the contamination from air that actually goes through

> the device. Most air does not. It stays on the other side of the

> room. And, of the air which does go through the device, much of

> it doesn't go through the filter. "

>

> So there are many reasons HEPA and high MERV filters don't

> work for us much of the time.

>

> Here's what does work, in order of decreasing effectiveness.

>

> A. Identify the contamination, where it is located, and remove it.

> You are no longer exposed because it is gone. If you can't

> remove the source the exposure won't stop until you remove

> yourself from it. That's why most on this group tell you to leave

> the house.

>

> B. If it can't be removed, isolate it. It is still present but it can't

> become airborne, so you are not exposed. An example is painting

> walls and ceilings. It covers the dust and dander so it can't get in

> the air. Or, containment of the mold remediation work area with

> plastic sheeting. Or, controlling air flow like Barb talks about with

> her attic. Keeping the air moving from the living space into the

> attic so it can't move from the attic back into the living space.

>

> C. If none of the above are sufficient, or possible, try dilution by

> ventilation. It mixes and some is removed. Like adding water to

> coffee that is too strong. Make it weaker by dilution. The pollution

> is still there and is still in the air. You are still exposed to it. But it

> is now at lower levels, hopefully below your threshold of reactivity.

>

> That's why it is less effective than removal or isolation. Also, it

> works better for odors than for particles. Assuming the outside air

> is clean, which is a real stretch nowadays. Just ask those living

> along the Gulf coast!

>

> D. Finally, the least effective method for both odors and particles

> is filtration. For all the reasons stated above.

>

> As an aside, some of you mentioned face masks. If you have an

> N-100 mask you know how hard it is to breath. That's because an

> N-100 is rated as a HEPA filter, which is MERV 17. The N-95 is

> much easier to breath through but it is now only 95% rather than

> 99.97% effective.

>

> What's the difference between 99.97% and 95%? Multiply the

> HEPA ratings by 166 and the 540,000 particle leak now becomes

> 90,000,000. That's how much difference. Huge! And that's

> through a properly functioning device or mask working at the

> same level as the filter. Good luck!

>

> But the main reason face masks are so lousy is because the

> edges don't fit tightly on the face as you move, talk, and breath.

> The air has an easier pathway around the edges much like in

> HEPA devices. Workers must be fit-tested to verify the mask is

> sealed to the face with no leakage. That requires a medical exam

> stating they are healthy enough to handle strained breathing.

>

> So, what many of you are experiencing about the limitations of air

> filters are true, whether you know why or not. Afterall, the air and

> the pollutants don't care what you know or think. And they don't

> read the HEPA device instruction manuals and they certainly

> don't care about the advertising claims. They behave according

> to their physical and chemical properties.

>

> Which is why it's important to know at least a little about them so

> you can make better decisions and figure out what to do when

> the " magic bullets " don't work.

>

> Carl Grimes

> Healthy Habitats LLC

>

> -----

> So even a high MERV filter for furnace or stand alone air cleaners, will not

catch these ultra fine particles and that is why one cannot depend on air

filters to solve contamination problem??

>

> ---

[Guest guest]

I have a MERV 16 filter on my Lennox Healthy Climate furnace. The installers

put it in wrong and it had dirt 'skid' marks around it when I went in to check

it after prolonged usage. I got a new one and put it in correctly but they are

soooo expensive that I delay replacing it even when I think it's time so am

considering moving to the lower MERV.

I'm disappointed in the way the Lennox Healthy Climate is made. It's as the air

conditioning industry are trying to kill us.

I replaced an old on Five in One which repair people said they believe

went out of business because their units were so well made, they never broke

down. The coil box in the on NEVER held any water ever. I had to

replace it only because basement floor shifted and drain hole of coil box got

off center and started to stay full of water, grew mold and then started to

overflow down into furnace. However it was about 40 years according to label on

it. I easily was able to lift up coil box access panel to it and check coil

area whereas my new Lennox coil box panel has 6 small phillips screws and a hose

that goes through the panel also that hampers opening it. Even the repair

person said " if I can get it open " , when I asked him when he serviced it, I'd

like to look inside coil box area when he opened it. He said 'if I can get it

open!! So if repairmen have trouble getting it open, how are homeowners supposed

to check it out. A rant of sorts against workmenship on all a/c. If anyone

hears of a lawsuit against the air conditioning industry, let me know. I'd love

to help in any way I can. I could provide a list of motel a/c units that empty

extra water right onto the motel room floors.

Incidentally when I mentioned to Lennox repairmen I was disappointed that the

coil pan did not drain well. He said that " all air conditioners hold water. It

won't cause any trouble " , but my question is WHY? Why build them so they hold

a little pool of water in your coil pan? I smelled it right away within a few

days of them putting the new a/c in. I corrected the situation by leaving the

air fan on continuous to dry the pan out but I didn't have to do that with my

old on unit, so I wonder why is it that the on company was able

to make make them correctly 40 years ago but they can't do it now?

Biggest problem facing America I'm beginning to think is lack of accurate

information and lack of concern about it, otherwise known as ignorance and

apathy, combined with a good helping of dishonesty and greed on part of big

business and government.

Anyway, thanks for the input on the MERV. There WAS alot of 'loose' dirt INSIDE

the filter box area that holds the filter in place, perhaps it bounced off

filter and falls to the bottom of box or maybe air is routing under filter and

depositing dirt there when filter is full, so I think I need to use a filter I

can afford to replace more often.

>

> 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.

>

>

[Guest guest]

With all this talk, I decided to go down and install my new replacement MERV16

which I just got and found something out. From taking filter in and out, a

piece of foam rubber came out, the other day. I didn't know what it was from so

put it aside. It was only about 3 inches long. When I put my new MERV filter

in it didn't seem to fit snugly as previous one had, so I took it out and

compared it to size of one I was removing and it is exact same size. Put the

hold one back in that used to fit snugly and notice it fits loosely too. Okay,

so the tiny 3 inch piece of foam that fell out was apparently in filter housing

and made filter FEEL as if it fit snugly, when in fact it does not! Arg! $10k

Lennox system. I'm going to write to them finally about a filter housing that

will allow air to flow around it without being filtered to a coil pan that is

usually holding water, that will smell mildewy if I don't run the fan continuous

to dry it out. I'd like to take an ad out and tell everyone to avoid the

expense. I might as well have bought a cheap one. So in addition to being

careful to always have the fan running, now I will need to make my own foam

strip and glue it to top of filter housing area so filter fits snugly really and

not just 'feel' snug, not just 3 inches as they did but all the way across.

Since they have it made with 3 inches only, maybe it needs this 'air release'

area so I will go down to a lower MERV so as not to burn out the motor. Jeez!

>

> I have a MERV 16 filter on my Lennox Healthy Climate furnace. The installers

put it in wrong and it had dirt 'skid' marks around it when I went in to check

it after prolonged usage. I got a new one and put it in correctly but they are

soooo expensive that I delay replacing it even when I think it's time so am

considering moving to the lower MERV.

>

> I'm disappointed in the way the Lennox Healthy Climate is made. It's as the

air conditioning industry are trying to kill us.

>