Re: Using furnace filters as whole house room air cleaners

[Guest guest]

No I give them a new filter Merv 11 filter Steve. No charge for the visit.

Re: Re: Using furnace filters as whole house room air cleaners

,When the owners are sick from mold in walls and carpeting with little money, you sell them a filter and tell them to keep their fan on and that makes them and you feel better? Nice consulting.I sure hope you tried harder than that to help them.Steve TemesIn a message dated 2/7/2007 2:05:19 PM Eastern Standard Time, garyrosen72652@ yahoo.com writes:

Mark, In an old house with bad carpets and mold in walls and owners with little money ... but they are sick from mold ... source removal may not be an option. In my experience very often putting in a Merv 11 air filter and turning the FAN=ON make everyeone feel better. The AC contractors don't like the AC to run with the FAN=ON but the now healthy people don't care about that. When you recommend this you don't make money but you feel good about helping people. Rosenwww.Mold-Books. com

Access over 1 million songs - Yahoo! Music Unlimited.

[Guest guest]

Group,

I have read several responses to the issue

of using furnace filters as whole house cleaners.

The air filtration industry has recognized

the importance air filtration has in keeping equipment

clean and today air filtration can also

become an effective tool in removing contaminants from

the air we breathe as well.

Many manufacturers are now fabricating 4”

and 5” MERV 8-11 filters designed for residential use.

By manufacturing an air filter with much

more surface area than the typical furnace (panel) type filters

They are now able to provide a homeowner

with adequate air filtration efficiency levels.

We all know we have landed men on the Moon

…1969; robots on Mars…2006 and now we are capable

of manufacturing air flirtation products

that are effective on particle sizes to help improve the air quality

in residential, institutional, commercial

and industrial process applications.

I will not go as far as some of my

colleagues stating that air filters may be the silver

bullet…however I will

state that adequate air filtration along

with effective air exchange rates and room pressurization can go a long

way in improving the overall Indoor Air

Quality (IAQ) of most application requirements today.

For more information I would suggest visiting

the National Air Filtration Association (NAFA) website at:

www.nafahq.org

for more information regarding furnace filters to High Efficiency Particulate

Air (HEPA) filters

including a most overlooked part of the

process, which is the proper installation and maintenance of the HVAC air

filtration systems.

I hope this helps…

Respectfully submitted,

AIR INDUSTRIES, INC.

North Andover, MA 01845

NAFA President 2006-2007

Office:

Fax:

Mobile:

Re: Using

furnace filters as whole house room air cleaners

Matt,

I agree. Using a HEPA bypass filter is like using a condom with a hole.

Besides, the real usefulness of the filter is to keep the equipment clean

and not to filter the house air.

House air is kept clean by minimizing dust and carpets.

C. May, M.A., CIAQP

May Indoor Air Investigations LLC

1522 Cambridge Street

Cambridge, MA 02139

www.mayindoorair.com

www.myhouseiskillingme.com

Matt Klein writes:

>

>> Any opinions from anyone on using a combination of in-line for

>> moderate filtering of all the air plus a bypass HEPA for filtering a

>> portion of the air all the time?

>

> I don't trust the HEPA systems myself. I have seen cases where the filter

> in these units also had bypass air. HEPAs require a tight fit, which

> usually means clamping, because they have so much pressure drop across the

> filter. With this much pressure drop, it doesn't take much of a leak to

> bypass the filter.

>

> I think the main reason I don't like these units is that they are a fox

> watching the hen house thing. No one regulates the claims of these guys.

> They like to tout the fact that is has a HEPA filter; but that only means

> that the FILTER was tested--not the whole system. Even if they produced

> test data, you have to question that. Interesting how test data can be

> found to support these kinds of things. Just look at the Idiot's Breeze.

> We have just too many products in this industry, and the allergy industry,

> that are unregulated, except in the courts.

>

>

>

> ******************************************************

> If what is written looks too stupid to be written by me, I disclaim it.

> On

> the other hand, if it is brilliant, then I have no one to blame but

> myself.

> Otherwise, whether you choose to accept my opinion is up to you.

> ******************************************************

> K. Klein, PE ME, MBA

> Indoor Air Quality Solutions, Inc.

> 2523 SR 133

> Bethel, OH 45106-0007

> VOICE:

> FAX: (with notice)

> E-mail: mkklein68roadrunner

> *******************************************************

>

> When I was younger, I had all of the answers.

> As I get older, I have discovered the questions.

[Guest guest]

Group,

I have read several responses to the issue of using furnace filters as

whole house cleaners.

, one of the MOST important points NOT made in your statements is

that most residential central air filter systems are not physically

constructed to handle anything more than a 1 " filter. In most

cases that I have observed, the air handler would have to be relocated to

accommodate a thicker filter. I have great respect for NAFA; but

until their attitudes somehow get down to the installation level, most

central filter systems will only be installed to take a 1 "

filter. Some of the world's greatest intentions have failed due to

failure to execute. Just look at OSU in this year's championship

game. :-(

************************************************************

K. Klein, PE ME, MBA

Indoor Air Quality Solutions, Inc.

2523 SR 133

Bethel, OH 45106-0007

VOICE:

FAX: (with notice)

E-mail: mkklein68@...

************************************************************

When I was younger, I had all of the answers.

As I get older, I have discovered the questions.?

[Guest guest]

Matt:

Yes! Very well put. On numerous occasions I have had to re-work the fan unit to install filter elements larger than what they were designed for, i.e., the 1” filter. Typically this involves installing a whole new filter frame upstream of the 1” slot. Half the time this is not a big effort, on the other occasions it is. However, to add to your thread, the other big mistake so often made by designers is locating the fan/filter unit in the attic of a home. People just will not climb into their attic to regularly change filters; it just isn’t done. Moreover, where is the typical attic access?.....Often it is a 24-inch square ceiling access panel in a closet. If anyone has closets like mine, there is not enuff room to get a ladder into my closets to get to the ceiling panel, and I believe many other folks have a similar condition, i.e., what storage space you have is filled to the brim. Fan units, and all other mechanical systems, should be located in a readily accessible mechanical closet that has sufficient room to maintain the equipment. Oh...I can hear the architects groan....”But this this takes-up valuable floor space!” BS! Architects be damn, mechanical equipment needs maintenance, and filter elements need REGULAR changing. Enuff of my soap box.

Group,

I have read several responses to the issue of using furnace filters as whole house cleaners.

, one of the MOST important points NOT made in your statements is that most residential central air filter systems are not physically constructed to handle anything more than a 1 " filter. In most cases that I have observed, the air handler would have to be relocated to accommodate a thicker filter. I have great respect for NAFA; but until their attitudes somehow get down to the installation level, most central filter systems will only be installed to take a 1 " filter. Some of the world's greatest intentions have failed due to failure to execute. Just look at OSU in this year's championship game. :-(

************************************************************

K. Klein, PE ME, MBA

Indoor Air Quality Solutions, Inc.

2523 SR 133

Bethel, OH 45106-0007

VOICE:

FAX: (with notice)

E-mail: mkklein68@...

************************************************************

When I was younger, I had all of the answers.

As I get older, I have discovered the questions.?

[Guest guest]

Good Morning

,

You are absolutely correct regarding the 1”

track typically provided for the homeowner…however having said that I

just

returned from the ASHRAE Expo in Dallas, TX and there were more than

a half dozen companies exhibiting filters for

residential use…They use a 4”

or 5” filter MERV 8-11) complete with housing, etc.

So it’s really NOT the ability to

manufacture effective and efficient air filters for home use …it’s

that they (decision makers) decide to put in a 1”

filter track…Today that is not an acceptable

filter depth … I understand some of the reasons why the 1” filter

slot/track is installed originally and that is:

The 1” filter is very

inexpensive cost is less than $ 1.00/ea.

The 1” filter (furnace

type MERV 1-4) has very little resistance typically .08” w.g. @ 300

feet per minute

The motor/blower required is

typically less than one horsepower for these types of filters

They (contractors) do not have

to live with the results of the 1” ineffective and inefficient furnace

filters

And last but not least you will

hear that “this is what we always use” for residential filter

applications

So what it really comes down to is this:

The homeowner/architect would

have to insist on a higher efficient (MERV 8-11) 4”, 5” or 6”

filter…

In fact they even manufacture

11 ½’ deep filters that last one year (MERV 14)  @ .36” w.g. @

500 fpm and .16”  w.g. @ 300 fpm

Manufacturers (r, Trane,

York, etc.) of HVAC equipment would need to upgrade their motor/blower

components.

Note: NAFA has invited several

of these Companies to give presentations to our association and they typically

state that if they

        did manufacture their

equipment with decent componenets, i.e. larger motor,etc. that would be able to

overcome the initial increase in pressre drop that they

            would lose out on all the bids

for these projects…so its all based on initial costs ONLY…and

the homeowner gets it in the end as usual.

If you took a brief survey of this

situation you would quickly realize that in the end most residential applications usually pay the

most and get the very least from just about everything they purchase including

HVAC filtration equipment, i.e. Commercial/Institutuonal grade versus

Residential grade…if given the choice of residential grade or commercial

grade of an air filtration system what would you want???

Anyway I’ll get off my soapbox for

now…I hope this helps clarify the use of furnace filters as whole house

air cleaners.

Respectfully submitted,   

AIR INDUSTRIES, INC.

North Andover, MA 01845

NAFA President, 2006-2007

Office:

Fax:

Mobile:

www.nafahq.org

RE: Re: Using

furnace filters as whole house room air cleaners

Group,

I have read several responses to the issue of using furnace filters as whole

house cleaners.

, one of the MOST important points NOT made in your statements is that

most residential central air filter systems are not physically constructed to

handle anything more than a 1 " filter. In most cases that I have

observed, the air handler would have to be relocated to accommodate a thicker

filter. I have great respect for NAFA; but until their attitudes somehow

get down to the installation level, most central filter systems will only be

installed to take a 1 " filter. Some of the world's greatest

intentions have failed due to failure to execute. Just look at OSU in

this year's championship game. :-(

************************************************************

K. Klein, PE ME, MBA

Indoor Air Quality Solutions, Inc.

2523 SR 133

Bethel, OH 45106-0007

VOICE:

FAX: (with notice)

E-mail: mkklein68roadrunner

************************************************************

When I was younger, I had all of the answers.

As I get older, I have discovered the questions.?

[Guest guest]

,

I agree …well said…today the “role

of air filtration” has been changed significantly.

Jeff was correct in stating that original role

(usefulness) of the air filter is to keep HVAC system components clean…

however today that statement is no longer

accurate.

you are also correct in stating

that air filters today are effectively used to keep not only the

HVAC components clean but to clean the air

of the occupied spaces to keep “the air that we breathe clean”.

Thank you for your insights.

Respectfully submitted,

AIR INDUSTRIES, INC.

North Andover, MA 01845

NAFA President, 2006-2007

Office:

Fax:

Mobile:

www.nafahq.org

Re: Re: Using

furnace filters as whole house room air cleaners

Jeff:

Respectfully disagree. Yes, filter are used to keep the HVAC equipment

clean. Filters are also a very good method of removing particulates from

the air and thereby improving IAQ. It is done all the time, i.e., filters

whose primary function is to clean the air; keeping the equipment clean is a

subordinate role of the filter.

For what it is worth....

On 2/7/07 4:22 PM, " Jeff May " <jeffmayindoorair>

wrote:

Matt,

I agree. Using a HEPA bypass filter is like using a condom with a hole.

Besides, the real usefulness of the filter is to keep the equipment clean

and not to filter the house air.

House air is kept clean by minimizing dust and carpets.

C. May, M.A., CIAQP

May Indoor Air Investigations LLC

1522 Cambridge Street

Cambridge, MA 02139

www.mayindoorair.com

www.myhouseiskillingme.com

Matt Klein writes:

>

>> Any opinions from anyone on using a combination of in-line for

>> moderate filtering of all the air plus a bypass HEPA for filtering a

>> portion of the air all the time?

>

> I don't trust the HEPA systems myself. I have seen cases where the

filter

> in these units also had bypass air. HEPAs require a tight fit, which

> usually means clamping, because they have so much pressure drop across the

> filter. With this much pressure drop, it doesn't take much of a leak

to

> bypass the filter.

>

> I think the main reason I don't like these units is that they are a fox

> watching the hen house thing. No one regulates the claims of these guys.

> They like to tout the fact that is has a HEPA filter; but that only means

> that the FILTER was tested--not the whole system. Even if they

produced

> test data, you have to question that. Interesting how test data can

be

> found to support these kinds of things. Just look at the Idiot's

Breeze.

> We have just too many products in this industry, and the allergy industry,

> that are unregulated, except in the courts.

>

>

>

> ******************************************************

> If what is written looks too stupid to be written by me, I disclaim it.

> On

> the other hand, if it is brilliant, then I have no one to blame but

> myself.

> Otherwise, whether you choose to accept my opinion is up to you.

> ******************************************************

> K. Klein, PE ME, MBA

> Indoor Air Quality Solutions, Inc.

> 2523 SR 133

> Bethel, OH 45106-0007

> VOICE:

> FAX: (with notice)

> E-mail: mkklein68roadrunner <mailto:mkklein68%40roadrunner.com>

> *******************************************************

>

> When I was younger, I had all of the answers.

> As I get older, I have discovered the questions.

[Guest guest]

I my experience if the house does not have active mold growth, the 1 inch filter is more than sufficient.

Rosen, Ph.D.

www.Mold-Books.com

RE: Re: Using furnace filters as whole house room air cleaners

Group,I have read several responses to the issue of using furnace filters as whole house cleaners.

, one of the MOST important points NOT made in your statements is that most residential central air filter systems are not physically constructed to handle anything more than a 1" filter. In most cases that I have observed, the air handler would have to be relocated to accommodate a thicker filter. I have great respect for NAFA; but until their attitudes somehow get down to the installation level, most central filter systems will only be installed to take a 1" filter. Some of the world's greatest intentions have failed due to failure to execute. Just look at OSU in this year's championship game. :-(

************ ********* ********* ********* ********* ********* *** K. Klein, PE ME, MBAIndoor Air Quality Solutions, Inc.2523 SR 133Bethel, OH 45106-0007VOICE: FAX: (with notice)E-mail: mkklein68@roadrunne r.com************ ********* ********* ********* ********* ********* ***When I was younger, I had all of the answers.As I get older, I have discovered the questions.?

Never Miss an EmailStay connected with Yahoo! Mail on your mobile. Get started!

[Guest guest]

Hi ,

I agree with you that MERV 11 filtration improves the air quality; I have

actually observed " 0 " particle counts coming out of clean duct systems with

these filters.

Nonetheless, from an IAQ perspective, in systems with AC coils, the most

important function of the filter is still to keep the coil, pan and liners

clean. Cleaning the air for breathing purposes is secondary.

Poor filtration in AC systems inevitably leads to microbial problems. Once a

system is contaminated, simply installing a better (or even the best) filter

will not necesarily eliminate a bioaerosol problem.

C. May, M.A., CIAQP

May Indoor Air Investigations LLC

1522 Cambridge Street

Cambridge, MA 02139

www.mayindoorair.com

www.myhouseiskillingme.com

W. writes:

> ,

>

>

>

> I agree .well said.today the " role of air filtration " has been changed

> significantly.

>

>

>

> Jeff was correct in stating that original role (usefulness) of the air

> filter is to keep HVAC system components clean.

>

> however today that statement is no longer accurate.

>

>

>

> you are also correct in stating that air filters today are

> effectively used to keep not only the

>

> HVAC components clean but to clean the air of the occupied spaces to

> keep " the air that we breathe clean " .

>

>

>

> Thank you for your insights.

>

>

>

> Respectfully submitted,

>

>

>

>

>

> AIR INDUSTRIES, INC.

>

> North Andover, MA 01845

>

> NAFA President, 2006-2007

>

> Office:

>

> Fax:

>

> Mobile:

>

> www.nafahq.org

>

>

>

[Guest guest]

Dear Jeff:

I too have seen very low particle counts for the supply air, however the people

and their activities in the space generate so much airborne particulate that I

wonder if you can go too far in this direciton.

Have you ever compared with resulting in space particle counts with the counts

in the supply air?

Bearg

White Pond

Concord, MA

-------------- Original message ----------------------

> Hi ,

>

> I agree with you that MERV 11 filtration improves the air quality; I have

> actually observed " 0 " particle counts coming out of clean duct systems with

> these filters.

>

> Nonetheless, from an IAQ perspective, in systems with AC coils, the most

> important function of the filter is still to keep the coil, pan and liners

> clean. Cleaning the air for breathing purposes is secondary.

>

> Poor filtration in AC systems inevitably leads to microbial problems. Once a

> system is contaminated, simply installing a better (or even the best) filter

> will not necesarily eliminate a bioaerosol problem.

>

> C. May, M.A., CIAQP

> May Indoor Air Investigations LLC

> 1522 Cambridge Street

> Cambridge, MA 02139

>

> www.mayindoorair.com

> www.myhouseiskillingme.com

>

>

> W. writes:

>

> > ,

> >

> >

> >

> > I agree .well said.today the " role of air filtration " has been changed

> > significantly.

> >

> >

> >

> > Jeff was correct in stating that original role (usefulness) of the air

> > filter is to keep HVAC system components clean.

> >

> > however today that statement is no longer accurate.

> >

> >

> >

> > you are also correct in stating that air filters today are

> > effectively used to keep not only the

> >

> > HVAC components clean but to clean the air of the occupied spaces to

> > keep " the air that we breathe clean " .

> >

> >

> >

> > Thank you for your insights.

> >

> >

> >

> > Respectfully submitted,

> >

> >

> >

> >

> >

> > AIR INDUSTRIES, INC.

> >

> > North Andover, MA 01845

> >

> > NAFA President, 2006-2007

> >

> > Office:

> >

> > Fax:

> >

> > Mobile:

> >

> > www.nafahq.org

> >

> >

> >

>

>

Hi ,

I agree with you that MERV 11 filtration improves the air quality; I have

actually observed " 0 " particle counts coming out of clean duct systems with

these filters.

Nonetheless, from an IAQ perspective, in systems with AC coils, the most

important function of the filter is still to keep the coil, pan and liners

clean. Cleaning the air for breathing purposes is secondary.

Poor filtration in AC systems inevitably leads to microbial problems. Once a

system is contaminated, simply installing a better (or even the best) filter

will not necesarily eliminate a bioaerosol problem.

C. May, M.A., CIAQP

May Indoor Air Investigations LLC

1522 Cambridge Street

Cambridge, MA 02139

www.mayindoorair.com

www.myhouseiskillingme.com

W. writes:

> ,

>

>

>

> I agree .well said.today the " role of air filtration " has been changed

> significantly.

>

>

>

> Jeff was correct in stating that original role (usefulness) of the air

> filter is to keep HVAC system components clean.

>

> however today that statement is no longer accurate.

>

>

>

> you are also correct in stating that air filters today are

> effectively used to keep not only the

>

> HVAC components clean but to clean the air of the occupied spaces to

> keep " the air that we breathe clean " .

>

>

>

> Thank you for your insights.

>

>

>

> Respectfully submitted,

>

>

>

>

>

> AIR INDUSTRIES, INC.

>

> North Andover, MA 01845

>

> NAFA President, 2006-2007

>

> Office:

>

> Fax:

>

> Mobile:

>

> www.nafahq.org

>

>

>

[Guest guest]

I just double checked the 3M website for their filtrete HVAC

filters. Their 1” is rated at MERV 8.

Am I missing something or is this a satisfactory solution to

redesigning the system for a 4” to 6” filter?

Banta

[Guest guest]

My

experience is that the static load of a one inch filter is significantly

greater than a 4-6 inch filter. The problems I have seen with the one

inch filters are that they stay in place way too long. When this happens,

the static load increases even more and the result is elevated humidity here in

Florida from

reduced air flow over the coil. I’m still a big fan of deep pleated

filters, though the one inch can work if it is truly changed out regularly.

Will Spates

IET

fax

Re: Using

furnace filters as whole house room air cleaners

I just double checked the 3M website

for their filtrete HVAC filters. Their 1” is rated at MERV 8.

Am I missing something or is this a

satisfactory solution to redesigning the system for a 4” to 6”

filter?

Banta

[Guest guest]

3M and others make different quality 1" filters. 3M offers 1" Merv 8, 9, 11. 3M also has their own rating system that goes beyond Merv.

For a nice description of filters, and ratings and a place to order custom sizes and thicknesses see www.filters-now.com

Rosen

www.Mold-Books.com

Re: Using furnace filters as whole house room air cleaners

I just double checked the 3M website for their filtrete HVAC filters. Their 1” is rated at MERV 8.

Am I missing something or is this a satisfactory solution to redesigning the system for a 4” to 6” filter?

Banta

Access over 1 million songs - Yahoo! Music Unlimited.

[Guest guest]

Regularly = as needed, which is a function of multiple variables.

Are the return airs all at floor level or at eye level or higher?

Is the house near a plowed field or a swamp?

Does the house door get opened once in the morning to go to work and

once in the evening to come home or are there 5 kids and 3 dogs going

in and out frequently?

Anybody smoking in the house?

Lots of take out fast food or plenty of pan frying?

Inspect every month until a pattern is decerned.

Ken

>

> What do you typically mean by regular change outs? Quarterly, bi-

monthly, monthly?

>

> TIA,

>

> Pete

>

> H. Carkhuff, ASCS, WRT

[Guest guest]

Thank you for your insights, Ken! - PeteKen Seger wrote: Regularly = as needed, which is a function of multiple variables.Are the return airs all at floor level or at eye level or higher?Is the house near a plowed field or a swamp?Does the house door get opened once in the morning to go to work and once in the evening to come home or are there 5 kids and 3 dogs going in and out frequently?Anybody smoking in the house?Lots of take out

fast food or plenty of pan frying?Inspect every month until a pattern is decerned.Ken>> What do you typically mean by regular change outs? Quarterly, bi-monthly, monthly?> > TIA,> > Pete> > H. Carkhuff, ASCS, WRT

TV dinner still cooling?Check out "Tonight's Picks" on Yahoo! TV.

[Guest guest]

If you turn the FAN=ON you will have to change your filters more often. Be happy about that as the crud in the filter is not being filtered out by your lungs. And what you spend in filters will be more than made up by savings in dusting and cleaning the home and fewer AC and AC duct cleaning and repairs.

Rosen

www.Mold-Books.com

Re: Using furnace filters as whole house room air cleaners

Regularly = as needed, which is a function of multiple variables.Are the return airs all at floor level or at eye level or higher?Is the house near a plowed field or a swamp?Does the house door get opened once in the morning to go to work and once in the evening to come home or are there 5 kids and 3 dogs going in and out frequently?Anybody smoking in the house?Lots of take out fast food or plenty of pan frying?Inspect every month until a pattern is decerned.Ken>> What do you typically mean by regular change outs? Quarterly, bi-monthly, monthly?> > TIA,> > Pete> > H. Carkhuff, ASCS, WRT

Be a PS3 game guru.Get your game face on with the latest PS3 news and previews at Yahoo! Games.

[Guest guest]

Ken

Good answer

Jim H. white

Re: Using furnace filters as whole house room air cleaners

Regularly = as needed, which is a function of multiple variables.Are the return airs all at floor level or at eye level or higher?Is the house near a plowed field or a swamp?Does the house door get opened once in the morning to go to work and once in the evening to come home or are there 5 kids and 3 dogs going in and out frequently?Anybody smoking in the house?Lots of take out fast food or plenty of pan frying?Inspect every month until a pattern is decerned.Ken>> What do you typically mean by regular change outs? Quarterly, bi-monthly, monthly?> > TIA,> > Pete> > H. Carkhuff, ASCS, WRT

[Guest guest]

Good

Afternoon Jeff,

I agree…I wouldn’t suggest

that you or anyone simply upgrade to a MERV 11 filter after a system is

contaminated due to prior poor filtration.

It has to start somewhere and if

homeowners had options to select for their residential HVAC and air filtration

systems you could start with a

decent 4” or 5” extended surface

MERV 11 filter…I believe Lennox has now began to manufacture such units for homeowners.

The scheduled change out would be every 6

months typically at the beginning of heating and cooling season. This would go

a long way to improve HVAC system hygiene as well as the overall Indoor Air

Quality…today more than ever before air filtration has gone way beyond the

scope of protecting HVAC system components to protecting the indoor air

environments for life, safety and health…proper air filtration selection

and maintenance has been a time tested and proven method that can help achieve

these goals, i.e. Clean-Rooms, Hospital Surgery Suites, TB Isolation Rooms,

Protective Environment Rooms, etc.

The other option for reducing or

eliminating bioaerosols … would be to place a final filter downstream of all

HVAC system components…

this is how Hospitals and Health Care Facilities

design their HVAC systems to protect the occupied spaces from these types of

contaminants.

I hope this helps clarify my position on

air filters and how they can be used effectively in homes, the workplace,

schools, and everywhere people need clean the air.

Respectfully submitted,

W.

AIR INDUSTRIES, INC.

North Andover, MA 01845

NAFA President 2006-2007

Office:

Fax:

Mobile:

Re: Using

furnace filters as whole house room air cleaners

Hi ,

I agree with you that MERV 11 filtration improves the air quality; I have

actually observed " 0 " particle counts coming out of clean duct

systems with

these filters.

Nonetheless, from an IAQ perspective, in systems with AC coils, the most

important function of the filter is still to keep the coil, pan and liners

clean. Cleaning the air for breathing purposes is secondary.

Poor filtration in AC systems inevitably leads to microbial problems. Once a

system is contaminated, simply installing a better (or even the best) filter

will not necesarily eliminate a bioaerosol problem.

C. May, M.A., CIAQP

May Indoor Air Investigations LLC

1522 Cambridge Street

Cambridge, MA 02139

www.mayindoorair.com

www.myhouseiskillingme.com

W. writes:

> ,

>

>

>

> I agree .well said.today the " role of air filtration " has been

changed

> significantly.

>

>

>

> Jeff was correct in stating that original role (usefulness) of the air

> filter is to keep HVAC system components clean.

>

> however today that statement is no longer accurate.

>

>

>

> you are also correct in stating that air filters today are

> effectively used to keep not only the

>

> HVAC components clean but to clean the air of the occupied spaces to

> keep " the air that we breathe clean " .

>

>

>

> Thank you for your insights.

>

>

>

> Respectfully submitted,

>

>

>

>

>

> AIR INDUSTRIES, INC.

>

> North Andover, MA 01845

>

> NAFA President, 2006-2007

>

> Office:

>

> Fax:

>

> Mobile:

>

> www.nafahq.org

>

>

>