RE: Use of UVC Light In Air Handlers

> " We are gratified that UVC technology has received this important

> recognition for its proven abilities to improve IAQ and infection

> control, save energy and reduce coil-cleaning costs. "

>

> (1) Infection control: Airborne pathogens are not likelyto be killed

> by the UV light in less than a second while pasingaroundthe UV

> light (unless you havea whole bank ofvery high power UV light in a

> series, saving energy?)

> (2) The only effective killing is on the surface where the UV light

> can reach constantly. If the unit were operated as designed,

> thereshould beno moisture accumulation.Then, there won't be

> microbial growth, thus no need for the UV light.

> (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am not an

> expert on HVAC system. From what I heard, using good filters (MERV

> 11) and regular mainatnce is what gets the jobs done. Please do

> comment if there is a real benefit from using UV light.

>

> Wei Tang

> QLab

>

> " , " wrote:

> Has anyone seen the article in the last IAQ Digest 1-9-2008 in which

> LEED points were given for the use of UVC Light in air handlers, any

> comments?

>

>

> Bob

>

> -------------------------Confidentiality Notice-----------------------

> ---

> This electronic message transmission contains information from the

> Los Angeles Department of Water and Power, which may be confidential.

> If you are not the intended recipient, be aware that any disclosure,

> copying, distribution or use of the content of this information is

> prohibited. If you have received this communication in error, please

> notify us immediately by e-mail and delete the original message and

> any attachment without reading or saving in any manner.

>

> Wei Tang, Ph.D.

> Lab Director

> QLab

> 5 Drive

> Cherry Hill, NJ 08003

>

>

January 15, 2008

Carl,

Their position changed in 2006 when they installed them on some

of their units from the factory. Has Trane been bought out?

Papageorge

CIAQP, CIEC, CRMI, CMRS

Alpha Consulting Group

Tampa, Florida

Phone:

From:

iequality [mailto:iequality ] On Behalf Of Carl

E. Grimes

Sent: Tuesday, January 15, 2008 2:32 PM

To: iequality

Subject: Re: Use of UVC Light In Air Handlers

The 2005 official corporate position statement

from Trane, which has

since been incorporated into their manuals, does not recommend it and

gives the reasons.

I'll FWD to anyone that requests it.

Carl Grimes

Healthy Habitats LLC

-----

>

> " We are gratified that UVC technology has received this important

> recognition for its proven abilities to improve IAQ and infection

> control, save energy and reduce coil-cleaning costs. "

>

> (1) Infection control: Airborne pathogens are not likelyto be killed

> by the UV light in less than a second while pasingaroundthe UV

> light (unless you havea whole bank ofvery high power UV light in a

> series, saving energy?)

> (2) The only effective killing is on the surface where the UV light

> can reach constantly. If the unit were operated as designed,

> thereshould beno moisture accumulation.Then, there won't be

> microbial growth, thus no need for the UV light.

> (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am not an

> expert on HVAC system. From what I heard, using good filters (MERV

> 11) and regular mainatnce is what gets the jobs done. Please do

> comment if there is a real benefit from using UV light.

>

> Wei Tang

> QLab

>

> " , "

wrote:

> Has anyone seen the article in the last IAQ Digest 1-9-2008 in which

> LEED points were given for the use of UVC Light in air handlers, any

> comments?

>

>

> Bob

>

> -------------------------Confidentiality Notice-----------------------

> ---

> This electronic message transmission contains information from the

> Los Angeles Department of Water and Power, which may be confidential.

> If you are not the intended recipient, be aware that any disclosure,

> copying, distribution or use of the content of this information is

> prohibited. If you have received this communication in error, please

> notify us immediately by e-mail and delete the original message and

> any attachment without reading or saving in any manner.

>

> Wei Tang, Ph.D.

> Lab Director

> QLab

> 5 Drive

> Cherry Hill, NJ 08003

>

>

January 15, 2008

Carl,

I would appreciate a copy of that.

Thank you,

Wayne Shellabarger

Acuity Engineers, Inc.

Wayne.s@...

Re: Use of

UVC Light In Air Handlers

The 2005 official

corporate position statement from Trane, which has

since been incorporated into their manuals, does not recommend it and

gives the reasons.

I'll FWD to anyone that requests it.

Carl Grimes

Healthy Habitats LLC

-----

>

> " We are gratified that UVC technology has received this important

> recognition for its proven abilities to improve IAQ and infection

> control, save energy and reduce coil-cleaning costs. "

>

> (1) Infection control: Airborne pathogens are not likelyto be killed

> by the UV light in less than a second while pasingaroundthe UV

> light (unless you havea whole bank ofvery high power UV light in a

> series, saving energy?)

> (2) The only effective killing is on the surface where the UV light

> can reach constantly. If the unit were operated as designed,

> thereshould beno moisture accumulation.Then, there won't be

> microbial growth, thus no need for the UV light.

> (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am not an

> expert on HVAC system. From what I heard, using good filters (MERV

> 11) and regular mainatnce is what gets the jobs done. Please do

> comment if there is a real benefit from using UV light.

>

> Wei Tang

> QLab

>

> " , " <robert.williamsladwp>

wrote:

> Has anyone seen the article in the last IAQ Digest 1-9-2008 in which

> LEED points were given for the use of UVC Light in air handlers, any

> comments?

>

>

> Bob

>

> -------------------------Confidentiality Notice-----------------------

> ---

> This electronic message transmission contains information from the

> Los Angeles Department of Water and Power, which may be confidential.

> If you are not the intended recipient, be aware that any disclosure,

> copying, distribution or use of the content of this information is

> prohibited. If you have received this communication in error, please

> notify us immediately by e-mail and delete the original message and

> any attachment without reading or saving in any manner.

>

> Wei Tang, Ph.D.

> Lab Director

> QLab

> 5 Drive

> Cherry Hill, NJ 08003

>

http://trane.com/Corporate/IR2007/resources/IR_Trane_Final.pdf

>

January 15, 2008

,

You're right, partially. They never said they wouldn't sell or

install them but would do so only on request. Their manuals now state

(I can send a copy of that also) they will sell them but only if they

are installed as an option and only at the factory, not as a later

add-on. So, yes, their position did change but the use of UV is not

encouraged and is actually more restrictive.

You're correct about being sold. Ingersoll Rand is purchasing Trane,

according to a Dec 17 press release at:

I wonder if that will affect their positon of UV?

Carl Grimes

Healthy Habitats LLC

-----

> Carl,

> Their position changed in 2006 when they installed them on some of

> their units from the factory. Has Trane been bought out?

>

> Papageorge

> CIAQP, CIEC, CRMI, CMRS

> Alpha Consulting Group

> Tampa, Florida

>

> Phone:

> From: iequality [mailto:iequality ] On

> Behalf Of Carl E. Grimes

> Sent: Tuesday, January 15, 2008 2:32 PM

> To: iequality

> Subject: Re: Use of UVC Light In Air Handlers

>

> The 2005 official corporate position statement from Trane, which has

> since been incorporated into their manuals, does not recommend it and

> gives the reasons.

>

> I'll FWD to anyone that requests it.

>

> Carl Grimes

> Healthy Habitats LLC

>

> -----

> >

> > " We are gratified that UVC technology has received this important

> > recognition for its proven abilities to improve IAQ and infection

> > control, save energy and reduce coil-cleaning costs. "

> >

> > (1) Infection control: Airborne pathogens are not likelyto be

> killed

> > by the UV light in less than a second while pasingaroundthe UV

> > light (unless you havea whole bank ofvery high power UV light in a

> > series, saving energy?)

> > (2) The only effective killing is on the surface where the UV light

> > can reach constantly. If the unit were operated as designed,

> > thereshould beno moisture accumulation.Then, there won't be

> > microbial growth, thus no need for the UV light.

> > (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am not

> an

> > expert on HVAC system. From what I heard, using good filters (MERV

> > 11) and regular mainatnce is what gets the jobs done. Please do

> > comment if there is a real benefit from using UV light.

> >

> > Wei Tang

> > QLab

> >

> > " , " wrote:

> > Has anyone seen the article in the last IAQ Digest 1-9-2008 in

> which

> > LEED points were given for the use of UVC Light in air handlers,

> any

> > comments?

> >

http://trane.com/Corporate/IR2007/resources/IR_Trane_Final.pdf

> >

> > Bob

> >

> > -------------------------Confidentiality Notice---------------------

> --

> > ---

> > This electronic message transmission contains information from the

> > Los Angeles Department of Water and Power, which may be

> confidential.

> > If you are not the intended recipient, be aware that any

> disclosure,

> > copying, distribution or use of the content of this information is

> > prohibited. If you have received this communication in error,

> please

> > notify us immediately by e-mail and delete the original message and

> > any attachment without reading or saving in any manner.

> >

> > Wei Tang, Ph.D.

> > Lab Director

> > QLab

> > 5 Drive

> > Cherry Hill, NJ 08003

> >

> > www.QLabUSA.com

> >

>

January 15, 2008

Thanks Carl, I would like a copy of that as well

Marty

radondude@...

January 16, 2008

As I recall the research on this said two

things, I would have to dig it out to find the quote:

The

airflow through the duct does not allow the bacteria, etc. to remain close

enough to the UV source for sufficient time to be affective.

If

the UV light is positioned so that it faces the dip pan so that it shines

directly on a pathogen it may be affect.

From: iequality

[mailto:iequality ] On Behalf

Of Carl E. Grimes

Sent: Tuesday, January 15, 2008

3:17 PM

To: iequality

Subject: RE: Use of

UVC Light In Air Handlers

,

You're right, partially. They never said they wouldn't sell or

install them but would do so only on request. Their manuals now state

(I can send a copy of that also) they will sell them but only if they

are installed as an option and only at the factory, not as a later

add-on. So, yes, their position did change but the use of UV is not

encouraged and is actually more restrictive.

You're correct about being sold. Ingersoll Rand is purchasing Trane,

according to a Dec 17 press release at:

I wonder if that will affect their positon of UV?

Carl Grimes

Healthy Habitats LLC

-----

> Carl,

> Their position changed in 2006 when they installed them on some of

> their units from the factory. Has Trane been bought out?

>

> Papageorge

> CIAQP, CIEC, CRMI, CMRS

> Alpha Consulting Group

> Tampa, Florida

>

> Phone:

> From: iequality

[mailto:iequality ]

On

> Behalf Of Carl E. Grimes

> Sent: Tuesday, January 15, 2008 2:32 PM

> To: iequality

> Subject: Re: Use of UVC Light In Air Handlers

>

> The 2005 official corporate position statement from Trane, which has

> since been incorporated into their manuals, does not recommend it and

> gives the reasons.

>

> I'll FWD to anyone that requests it.

>

> Carl Grimes

> Healthy Habitats LLC

>

> -----

> >

> > " We are gratified that UVC technology has received this

important

> > recognition for its proven abilities to improve IAQ and infection

> > control, save energy and reduce coil-cleaning costs. "

> >

> > (1) Infection control: Airborne pathogens are not likelyto be

> killed

> > by the UV light in less than a second while pasingaroundthe UV

> > light (unless you havea whole bank ofvery high power UV light in a

> > series, saving energy?)

> > (2) The only effective killing is on the surface where the UV light

> > can reach constantly. If the unit were operated as designed,

> > thereshould beno moisture accumulation.Then, there won't be

> > microbial growth, thus no need for the UV light.

> > (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am not

> an

> > expert on HVAC system. From what I heard, using good filters (MERV

> > 11) and regular mainatnce is what gets the jobs done. Please do

> > comment if there is a real benefit from using UV light.

> >

> > Wei Tang

> > QLab

> >

> > " , " <robert.williamsladwp>

wrote:

> > Has anyone seen the article in the last IAQ Digest 1-9-2008 in

> which

> > LEED points were given for the use of UVC Light in air handlers,

> any

> > comments?

> >

> http://trane.com/Corporate/IR2007/resources/IR_Trane_Final.pdf

> >

> > Bob

> >

> > -------------------------Confidentiality Notice---------------------

> --

> > ---

> > This electronic message transmission contains information from the

> > Los Angeles Department of Water and Power, which may be

> confidential.

> > If you are not the intended recipient, be aware that any

> disclosure,

> > copying, distribution or use of the content of this information is

> > prohibited. If you have received this communication in error,

> please

> > notify us immediately by e-mail and delete the original message and

> > any attachment without reading or saving in any manner.

> >

> > Wei Tang, Ph.D.

> > Lab Director

> > QLab

> > 5 Drive

> > Cherry Hill, NJ 08003

> >

> > www.QLabUSA.com

> >

>

-------------------------Confidentiality Notice--------------------------This electronic message transmission contains information from the Los Angeles Department of Water and Power, which may be confidential. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the content of this information is prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the original message and any attachment without reading or saving in any manner.

January 16, 2008

,

That is my recollection also, even though many bacteria needed

only a second or less exposure. Fungi, on the other hand, needed

at least 5 seconds for the small translucent spores and as much as

3 minutes for the larger dark spores.

Carl Grimes

Healthy Habitats LLC

-----

On Wed Jan 16 09:51:24 CST 2008, " , "

wrote:

> As I recall the research on this said two things, I would have to

> dig it

> out to find the quote:

>

> 1. The airflow through the duct does not allow the bacteria,

> etc.

> to remain close enough to the UV source for sufficient time to be

> affective.

> 2. If the UV light is positioned so that it faces the dip pan so

> that it shines directly on a pathogen it may be affect.

>

> ________________________________

>

> From: iequality

> [mailto:iequality ] On

> Behalf Of Carl E. Grimes

> Sent: Tuesday, January 15, 2008 3:17 PM

> To: iequality

> Subject: RE: Use of UVC Light In Air Handlers

>

> ,

>

> You're right, partially. They never said they wouldn't sell or

> install them but would do so only on request. Their manuals now

> state (I can send a copy of that also) they will sell them but

> only if they are installed as an option and only at the factory,

> not as a later add-on. So, yes, their position did change but the

> use of UV is not encouraged and is actually more restrictive.

>

> You're correct about being sold. Ingersoll Rand is purchasing

> Trane, according to a Dec 17 press release at:

> <http://trane.com/Corporate/IR2007/resources/IR_Trane_Final.pdf>

> I wonder if that will affect their positon of UV?

>

> Carl Grimes

> Healthy Habitats LLC

>

> -----

>> Carl,

>> Their position changed in 2006 when they installed them on some

>> of their units from the factory. Has Trane been bought out?

>>

>> Papageorge

>> CIAQP, CIEC, CRMI, CMRS

>> Alpha Consulting Group

>> Tampa, Florida

>>

>> Phone:

>> From: iequality

>> <mailto:iequality%40yahoogroups.com>

> [mailto:iequality

> <mailto:iequality%40yahoogroups.com> ]

> On

>> Behalf Of Carl E. Grimes

>> Sent: Tuesday, January 15, 2008 2:32 PM

>> To: iequality

>> <mailto:iequality%40yahoogroups.com> Subject: Re:

>> Use of UVC Light In Air Handlers

>>

>> The 2005 official corporate position statement from Trane, which

>> has since been incorporated into their manuals, does not

>> recommend it and gives the reasons.

>>

>> I'll FWD to anyone that requests it.

>>

>> Carl Grimes

>> Healthy Habitats LLC

>>

>> -----

>> > > http://www.steril-aire.com/news.htm#LEED

> <http://www.steril-aire.com/news.htm#LEED>

>> > " We are gratified that UVC technology has received this

>> important > recognition for its proven abilities to improve IAQ

>> and infection > control, save energy and reduce coil-cleaning

>> costs. "

>> > > (1) Infection control: Airborne pathogens are not likelyto

>> be killed > by the UV light in less than a second while

>> pasingaroundthe UV > light (unless you havea whole bank ofvery

>> high power UV light in a > series, saving energy?)

>> > (2) The only effective killing is on the surface where the UV

>> light > can reach constantly. If the unit were operated as

>> designed, > thereshould beno moisture accumulation.Then, there

>> won't be > microbial growth, thus no need for the UV light. >

>> (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am

>> not an > expert on HVAC system. From what I heard, using good

>> filters (MERV > 11) and regular mainatnce is what gets the jobs

>> done. Please do > comment if there is a real benefit from using

>> UV light. > > Wei Tang

>> > QLab

>> > > > " , " <robert.williams@...

> <mailto:robert.williams%40ladwp.com> > wrote:

>> > Has anyone seen the article in the last IAQ Digest 1-9-2008 in

>> which > LEED points were given for the use of UVC Light in air

>> handlers, any > comments?

>> > > http://www.steril-aire.com/news.htm#LEED

> <http://www.steril-aire.com/news.htm#LEED>

>> > > Bob

>> > > -------------------------Confidentiality

>> Notice---------------------

>> --

>> > ---

>> > This electronic message transmission contains information from

>> the > Los Angeles Department of Water and Power, which may be

>> confidential. > If you are not the intended recipient, be aware

>> that any disclosure, > copying, distribution or use of the

>> content of this information is > prohibited. If you have

>> received this communication in error, please > notify us

>> immediately by e-mail and delete the original message and > any

>> attachment without reading or saving in any manner.

>> > > > > > > > > Wei Tang, Ph.D.

>> > Lab Director

>> > QLab

>> > 5 Drive

>> > Cherry Hill, NJ 08003

>> >

>> > www.QLabUSA.com

>> > >

>

> -------------------------Confidentiality

> Notice--------------------------

> This electronic message transmission contains information from

> the Los Angeles Department of Water and Power, which may be

> confidential. If you are not the intended recipient, be aware

> that any disclosure, copying, distribution or use of the content

> of this information is prohibited. If you have received this

> communication in error, please notify us immediately by e-mail

> and delete the original message and any attachment without

> reading or saving in any manner.

>

January 17, 2008

Besides time, the dose of UV exposure also depends on the distance of microorganisms to the UV source. The bacteria fly by 10 cm away from the UV is being killed roughly 100 times less effective than those fly by 1 cm away assuming the time of exposure is the same. Wei Tang QLabCarl Grimes wrote: ,That is my recollection also, even though many bacteria needed only a second or less exposure. Fungi, on the other hand, needed at least 5 seconds for the

small translucent spores and as much as 3 minutes for the larger dark spores.Carl GrimesHealthy Habitats LLC-----On Wed Jan 16 09:51:24 CST 2008, ", " <robert.williamsladwp> wrote:> As I recall the research on this said two things, I would have to > dig it> out to find the quote:> > 1. The airflow through the duct does not allow the bacteria, > etc.> to remain close enough to the UV source for sufficient time to be> affective.> 2. If the UV light is positioned so that it faces the dip pan so> that it shines directly on a pathogen it may be affect.> > ________________________________> > From: iequality > [mailto:iequality ] On> Behalf Of Carl E. Grimes> Sent: Tuesday, January 15, 2008 3:17 PM> To: iequality > Subject: RE: Use of UVC Light In Air Handlers> > ,> > You're right, partially. They never said they wouldn't sell or > install them but would do so only on request. Their manuals now > state (I can send a copy of that also) they will sell them but > only if they are installed as an option and only at the factory, > not as a later add-on. So, yes, their position did change but the > use of UV is not encouraged and is actually more restrictive.> > You're correct about being sold. Ingersoll Rand is purchasing > Trane, according to a Dec 17 press release at: > http://trane.com/Corporate/IR2007/resources/IR_Trane_Final.pdf> <http://trane.com/Corporate/IR2007/resources/IR_Trane_Final.pdf> > I wonder if that will affect their positon of UV?> > Carl Grimes> Healthy Habitats LLC> > ----->> Carl,>> Their position changed in 2006 when they installed them on some >> of their units from the factory. Has Trane been bought out?>> >> Papageorge>> CIAQP, CIEC, CRMI, CMRS>> Alpha Consulting Group>> Tampa, Florida>> >> Phone: >> From: iequality >>

<mailto:iequality%40yahoogroups.com>> [mailto:iequality > <mailto:iequality%40yahoogroups.com> ]> On>> Behalf Of Carl E. Grimes>> Sent: Tuesday, January 15, 2008 2:32 PM>> To: iequality >> <mailto:iequality%40yahoogroups.com> Subject: Re: >> Use of UVC Light In Air Handlers>> >> >> >> The 2005 official corporate position statement from Trane, which >> has since been incorporated into their manuals, does not >> recommend it and gives the reasons.>> >> I'll FWD to anyone that requests it.>> >> Carl Grimes>> Healthy Habitats LLC>> >> ----->> > > http://www.steril-aire.com/news.htm#LEED> <http://www.steril-aire.com/news.htm#LEED>>> > "We are gratified that UVC technology has received this >> important > recognition for its proven abilities to improve IAQ >> and infection > control, save energy and reduce coil-cleaning >> costs.">> > > (1) Infection control: Airborne pathogens are not likelyto >> be killed > by the UV light in less than a second while >> pasingaroundthe UV > light (unless you havea whole bank ofvery >> high power UV light in a > series, saving energy?)>> > (2) The only effective killing is on the surface where the UV >> light > can reach constantly. If the unit were operated as >> designed, > thereshould beno

moisture accumulation.Then, there >> won't be > microbial growth, thus no need for the UV light. > >> (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am >> not an > expert on HVAC system. From what I heard, using good >> filters (MERV > 11) and regular mainatnce is what gets the jobs >> done. Please do > comment if there is a real benefit from using >> UV light. > > Wei Tang>> > QLab>> > > > ", " <robert.williamsladwp> <mailto:robert.williams%40ladwp.com> > wrote:>> > Has anyone seen the article in the last IAQ Digest 1-9-2008 in >> which > LEED points were given for the use of UVC Light in air >> handlers, any > comments?>> > > http://www.steril-aire.com/news.htm#LEED> <http://www.steril-aire.com/news.htm#LEED>>> > > Bob >> > > -------------------------Confidentiality >> Notice--------------------->> -->> > --->> > This electronic message transmission contains information from >> the > Los Angeles Department of Water and Power, which may be >> confidential. > If you are not the intended recipient, be aware >> that any disclosure, > copying, distribution or use of the >> content of this information is > prohibited. If you have >> received this communication in error, please > notify us >> immediately by e-mail and delete the original message and > any >>

attachment without reading or saving in any manner.>> > > > > > > > > Wei Tang, Ph.D.>> > Lab Director>> > QLab>> > 5 Drive>> > Cherry Hill, NJ 08003>> > >> > www.QLabUSA.com>> > >> > -------------------------Confidentiality > Notice--------------------------> This electronic message transmission contains information from > the Los Angeles Department of Water and Power, which may be > confidential. If you are not the intended recipient, be aware > that any disclosure, copying, distribution or use of the content > of this information is prohibited. If you have received this > communication in error, please notify us immediately by e-mail > and delete the original message and any attachment without > reading or saving

in any manner.> Wei Tang, Ph.D. Lab Director QLab5 DriveCherry Hill, NJ 08003 Faxwww.QLabUSA.com

January 17, 2008

Wei

In some commercial applications, long stretches of ducting are fitted with UV mirror-like surfaces that allow the light to reflect back and forth through the air that is going down this section of duct. As you can imagine the exposure of any one suspended particle is quite high, so the dose and the "kill" factor are too.

If we are not looking at triggering mechanisms, I believe that the dose is still the poison. Many of our sensitized clients/friends/compatriots are in a sub-population that has a heightened response that may not be like the average person, so I wonder if there are easy ways to determine whether or not all of the biologicals that we want to "kill" are of one standard population; somehow I doubt it.

Jim H. White SSC

Re: >> Use of UVC Light In Air Handlers>> >> >> >> The 2005 official corporate position statement from Trane, which >> has since been incorporated into their manuals, does not >> recommend it and gives the reasons.>> >> I'll FWD to anyone that requests it.>> >> Carl Grimes>> Healthy Habitats LLC>> >> ----->> > > http://www.steril-aire.com/news.htm#LEED> <http://www.steril-aire.com/news.htm#LEED>>> > "We are gratified that UVC technology has received this >> important > recognition for its proven abilities to improve IAQ >> and infection > control, save energy and reduce coil-cleaning >> costs.">> > > (1) Infection control: Airborne pathogens are not likelyto >> be killed > by the UV light in less than a second while >> pasingaroundthe UV > light (unless you havea whole bank ofvery >> high power UV light in a > series, saving energy?)>> > (2) The only effective killing is on the surface where the UV >> light > can reach constantly. If the unit were operated as >> designed, > thereshould beno moisture accumulation.Then, there >> won't be > microbial growth, thus no need for the UV light. > >> (2) Improve IAQ, save energy,reduce coil-cleaning costs: I am >> not an > expert on HVAC system. From what I heard, using good >> filters (MERV > 11) and regular mainatnce is what gets the jobs >> done. Please do > comment if there is a real benefit from using >> UV light. > > Wei Tang>> > QLab>> > > > ", " <robert.williamsladwp> <mailto:robert.williams%40ladwp.com> > wrote:>> > Has anyone seen the article in the last IAQ Digest 1-9-2008 in >> which > LEED points were given for the use of UVC Light in air >> handlers, any > comments?>> > > http://www.steril-aire.com/news.htm#LEED> <http://www.steril-aire.com/news.htm#LEED>>> > > Bob >> > > -------------------------Confidentiality >> Notice--------------------->> -->> > --->> > This electronic message transmission contains information from >> the > Los Angeles Department of Water and Power, which may be >> confidential. > If you are not the intended recipient, be aware >> that any disclosure, > copying, distribution or use of the >> content of this information is > prohibited. If you have >> received this communication in error, please > notify us >> immediately by e-mail and delete the original message and > any >> attachment without reading or saving in any manner.>> > > > > > > > > Wei Tang, Ph.D.>> > Lab Director>> > QLab>> > 5 Drive>> > Cherry Hill, NJ 08003>> > >> > www.QLabUSA.com>> > >> > -------------------------Confidentiality > Notice--------------------------> This electronic message transmission contains information from > the Los Angeles Department of Water and Power, which may be > confidential. If you are not the intended recipient, be aware > that any disclosure, copying, distribution or use of the content > of this information is prohibited. If you have received this > communication in error, please notify us immediately by e-mail > and delete the original message and any attachment without > reading or saving in any manner.>

Wei Tang, Ph.D.

Lab Director

QLab5 DriveCherry Hill, NJ 08003

Faxwww.QLabUSA.com

January 17, 2008

If spores or bacteria are flying by a UV light in a duct system you could have (and should have) filtered them with a good filter. If you made sure they didn't become airborne by preventing growth in the first place and by removing contaminants (not just viable spores) from surfaces if growth has occurred you wouldn't even need an especially good filter.

I see no reason to install a UV light in a duct system in a normal building -- maybe in an AIDS ward or where organ transplant patients recover or an animal laboratory where control of infectious biological agents is more critical.

There are better ways to prevent growth on coils and in drain pans than relying on UV light.

What would you need to kill in a duct system in a residence or office building? And wouldn't transmission of an infectious agent occur directly from fomites or aerosol droplets or suspended spores in the occupied space rather than from a supply diffuser or register?

People seem to feel that high-tech, expensive gizmos, especially ones that are shiny with bright lights, are needed to kill things they can't see. It's money poorly spent, in my opinion. Why it was a requirement at one time for GSA buildings and why the USGBC considers it worthy of LEED credit is beyond me.

Steve Temes

Besides time, the dose of UV exposure also depends on the distance of microorganisms to the UV source. The bacteria fly by 10 cm away from the UV is being killed roughly 100 times less effective than those fly by 1 cm away assuming the time of exposure is the same.

Wei Tang

QLab

Carl Grimes wrote:

,

That is my recollection also, even though many bacteria needed

only a second or less exposure. Fungi, on the other hand, needed

at least 5 seconds for the small translucent spores and as much as

3 minutes for the larger dark spores.

Carl Grimes

Healthy Habitats LLC

January 17, 2008

Jim,

Can you or others point us to a company, an installation or case

study using the extended pathway method of UV exposure? I've not

heard of it before but am intrigued because an off-line

conversation suggested 100 feet was needed at a " typical " airflow

speed.

Anybody: If extended pathway/times are possible, could we expect

changes beyond non-viability to occur, such as de-naturing?

Carl Grimes

Healthy Habitats LLC

-----

On Thu Jan 17 10:12:57 CST 2008, " Jim H. White "

wrote:

> Wei

> In some commercial applications, long stretches of ducting are

> fitted with UV mirror-like surfaces that allow the light to

> reflect back and forth through the air that is going down this

> section of duct. As you can imagine the exposure of any one

> suspended particle is quite high, so the dose and the " kill "

> factor are too. If we are not looking at triggering mechanisms, I

> believe that the dose is still the poison. Many of our sensitized

> clients/friends/compatriots are in a sub-population that has a

> heightened response that may not be like the average person, so I

> wonder if there are easy ways to determine whether or not all of

> the biologicals that we want to " kill " are of one standard

> population; somehow I doubt it.

> Jim H. White SSC

>

> Re:

> >> Use of UVC Light In Air Handlers

> >> >> >> >> The 2005 official corporate position

> statement from Trane, which >> has since been incorporated

> into their manuals, does not >> recommend it and gives the

> reasons.

> >> >> I'll FWD to anyone that requests it.

> >> >> Carl Grimes

> >> Healthy Habitats LLC

> >> >> -----

> >> > > http://www.steril-aire.com/news.htm#LEED

> > <http://www.steril-aire.com/news.htm#LEED>

> >> > " We are gratified that UVC technology has received this

> >> important > recognition for its proven abilities to improve

> IAQ >> and infection > control, save energy and reduce

> coil-cleaning >> costs. "

> >> > > (1) Infection control: Airborne pathogens are not

> likelyto >> be killed > by the UV light in less than a second

> while >> pasingaroundthe UV > light (unless you havea whole

> bank ofvery >> high power UV light in a > series, saving

> energy?)

> >> > (2) The only effective killing is on the surface where

> the UV >> light > can reach constantly. If the unit were

> operated as >> designed, > thereshould beno moisture

> accumulation.Then, there >> won't be > microbial growth, thus

> no need for the UV light. > >> (2) Improve IAQ, save

> energy,reduce coil-cleaning costs: I am >> not an > expert on

> HVAC system. From what I heard, using good >> filters (MERV >

> 11) and regular mainatnce is what gets the jobs >> done.

> Please do > comment if there is a real benefit from using >>

> UV light. > > Wei Tang

> >> > QLab

> >> > > > " , " <robert.williams@...

> > <mailto:robert.williams%40ladwp.com> > wrote:

> >> > Has anyone seen the article in the last IAQ Digest

> 1-9-2008 in >> which > LEED points were given for the use of

> UVC Light in air >> handlers, any > comments?

> >> > > http://www.steril-aire.com/news.htm#LEED

> > <http://www.steril-aire.com/news.htm#LEED>

> >> > > Bob

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> >> > > > > > > > > Wei Tang, Ph.D.

> >> > Lab Director

> >> > QLab

> >> > 5 Drive

> >> > Cherry Hill, NJ 08003

> >> >

> >> > www.QLabUSA.com

> >> > >

> > > -------------------------Confidentiality >

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> > Wei Tang, Ph.D.

> Lab Director

> QLab

> 5 Drive

> Cherry Hill, NJ 08003

>

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