RE: coil and drain pan odor

[Guest guest]

I think there are some biocide chemicals that can be sprayed onto

coils and drain pan to kill any bacteria, etc. Information I have seen

indicates that UV lights have limited effectiveness.

Check to make sure the pan is draining when the fan is running. If the

air handling unit is a draw through arrangement, the negative static

pressure in the unit may keep the water from draining. If the unit is

a blow through arrangement, check to see if the water seal in the trap

for the condensate drain has not dried out or has been pushed out by

the static pressure in the unit. if so, it may be drawing sewer gases

into the circulated air.

Check the air velocity through the cooling coil. If it is too high,

water droplets may be blown beyond the condensate pan.

Tom in St. Louis

>

> Group,

>

> A long standing problem with the building I work out of, along with

many others I'm called to look at, is the chronic summer-time musty

odor coming from the cooling coils and/or condensate drain pan. Any

recommendations of products/treatments (other than ozone or UV lights,

please!) that you know to be successful - especially for the cooling

coils?

>

> Curtis Redington, RS

> Environmental Quality Specialist

> City of Wichita Dept. of Environmental Health

> Wichita KS

>

[Guest guest]

,

Yes, that's what I'm referring to. I also know that there are many, many products marketed to treat this problem. What I'm hoping for are some recommendations of specific products (or types of products) that the non-salespeople on this List have experience with. Do enzymes work better than disinfectants? What type enzyme? Or what type disinfectants? Seems to me one of the biggest challenges would be getting a product with good residual kill on the offending bacteria without also killing all the people downstream. Also, how about application? Drain pans would be easy enough (toss in some tablets), but it would be tough to get good saturation of the coil surfaces (which is where I think the bulk of the odor is coming from).

Curtis

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of MoffettSent: Tuesday, June 27, 2006 10:22 AMTo: iequality Subject: RE: coil and drain pan odorSensitivity: Private

Curtis,

The symptom you are talking about is called “dirty socks.” This biological condition has been around for 25 years that I am aware of. There are cleaning and disinfectant chemicals specifically designed to get rid of this problem.

Moffett

From: iequality [mailto:iequality ] On Behalf Of Redington, CurtisSent: Tuesday, June 27, 2006 6:59 AMTo: iequality Subject: coil and drain pan odorSensitivity: Private

Group,

A long standing problem with the building I work out of, along with many others I'm called to look at, is the chronic summer-time musty odor coming from the cooling coils and/or condensate drain pan. Any recommendations of products/treatments (other than ozone or UV lights, please!) that you know to be successful - especially for the cooling coils?

Curtis Redington, RS Environmental Quality Specialist City of Wichita Dept. of Environmental Health Wichita KS

[Guest guest]

What are the coils made of aluminum,

copper, ???

" Tony " Havics, CHMM, CIH, PE

...............................................

pH2, LLC

PO Box 34140

Indianapolis, IN 46234

Cell

Fax

90% of Risk Management is knowing where to place the decimal point...any

consultant can give you the other 10%(SM)

This message is from pH2. This message and any attachments may contain legally

privileged or confidential information, and are intended only for the

individual or entity identified above as the addressee. If you are not the

addressee, or if this message has been addressed to you in error, you are not

authorized to read, copy, or distribute this message and any attachments, and

we ask that you please delete this message and attachments (including all

copies) and notify the sender by return e-mail or by phone at .

Delivery of this message and any attachments to any person other than the

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privilege. All personal messages express views only of the sender, which are

not to be attributed to pH2 and may not be copied or distributed without this

statement.

From: iequality [mailto:iequality ] On Behalf Of Redington, Curtis

Sent: Tuesday, June 27, 2006 8:59

AM

To: iequality

Subject: coil and

drain pan odor

Sensitivity: Private

Group,

A

long standing problem with the building I work out of, along with many others

I'm called to look at, is the chronic summer-time musty odor coming from the

cooling coils and/or condensate drain pan. Any recommendations of

products/treatments (other than ozone or UV lights, please!) that you know to

be successful - especially for the cooling coils?

Curtis

Redington, RS

Environmental

Quality Specialist

City of Wichita

Dept. of Environmental Health

Wichita KS

[Guest guest]

What are the coils made of aluminum, copper, ???

Generally aluminum fins, copper coils, and galvanized end plates for direct expansion systems. Flooded systems can use steel tubing and fins...depends on the application and refrigerant used.

Odors are always a service pain. Do your systems draw unconditioned air in as make up air? I have found many chronic problems with systems condensing outside air in the cabinets once the thermostats are satisfied . Hence mold, odors and bacteria really get a hold in the insulation. Also check the usual suspects drain pans, too high delta T ( belts)...

I have used BBJ products with success but note any fogging tends to disrupt the natural balance , sometimes the bad guys get stronger. UV lights eat belts, wiring , motor windings, plastic drain pans, and service people's eyes , as well as destroying bacteria, in irradiated areas.

If the systems are found clean ... I have had problems with one mfg's coil. When they were exposed to diesel exhaust in low concentrations they reeked as they corroded . There again is a fresh air intake problem.

Good luck

Valin

[Guest guest]

Try

talking with Grant Shallcross at Aeris technologies in Australia, gshallcross@.... He

has a company that has developed an enzyme treatment for cooling coils.

Initial results look interesting although I don’t think in has been scientifically

validated in a controlled study in the field. I know of some HVAC

cleaners who are using it with many favourable reports.

Robyn

Dr Robyn Phipps

Institute of Technology

and Engineering 456

Massey

University

Private Bag 11 222

Palmerston North

New Zealand

DD ++ 64 6 350 5107

Fax ++ 64 6 350 5604

-----Original

Message-----

From: iequality

[mailto:iequality ] On Behalf

Of Redington, Curtis

Sent: Wednesday, 28 June 2006 1:59

a.m.

To: iequality

Subject: coil and

drain pan odor

Sensitivity: Private

Group,

A long standing problem with the building I work out

of, along with many others I'm called to look at, is the chronic summer-time

musty odor coming from the cooling coils and/or condensate drain pan. Any

recommendations of products/treatments (other than ozone or UV lights, please!)

that you know to be successful - especially for the cooling coils?

Curtis Redington, RS

Environmental

Quality Specialist

City

of Wichita Dept. of Environmental Health

Wichita

KS

[Guest guest]

Curtis,

Serious drain pan issues caused by

biologically contaminated coils is an issue that seems to keep coming up in my

life. I have had very little success with chemical cleaners and disinfectants,

no matter what the chemical product manufacturer states or claims. In one case,

we could not get rid of the problem for a state hospital and instead of putting

up with the nuisance odors transferred into the patient population, we decided

with the building engineers to replace the HVAC coils. (Yes, the HVAC system was

a roof type, to where we were not dealing with a major HVAC system.) With an

ongoing cleaning and maintenance program, this took care of the problem.

Moffett

From:

iequality [mailto:iequality ] On Behalf Of Redington, Curtis

Sent: Tuesday, June 27, 2006 9:47

AM

To: iequality

Subject: RE: coil and

drain pan odor

Sensitivity: Private

,

Yes, that's what I'm referring to. I also

know that there are many, many products marketed to treat this problem. What

I'm hoping for are some recommendations of specific products (or types of

products) that the non-salespeople on this List have experience with. Do

enzymes work better than disinfectants? What type enzyme? Or what type

disinfectants? Seems to me one of the biggest challenges would be getting a

product with good residual kill on the offending bacteria without also killing

all the people downstream. Also, how about application? Drain pans would be

easy enough (toss in some tablets), but it would be tough to get good

saturation of the coil surfaces (which is where I think the bulk of the odor is

coming from).

Curtis

coil and

drain pan odor

Sensitivity: Private

Group,

A

long standing problem with the building I work out of, along with many others

I'm called to look at, is the chronic summer-time musty odor coming from the

cooling coils and/or condensate drain pan. Any recommendations of

products/treatments (other than ozone or UV lights, please!) that you know to

be successful - especially for the cooling coils?

Curtis

Redington, RS

Environmental

Quality Specialist

City of Wichita Dept. of Environmental Health

Wichita KS

[Guest guest]

The fins on cooling coils are aluminum and the tubes through which the

refrigerant or chilled water flows are copper.

Tom in St. Louis

>

> What are the coils made of aluminum, copper, ???

>

>

>

>

>

> " Tony " Havics, CHMM, CIH, PE

> ..............................................

> pH2, LLC

> PO Box 34140

> Indianapolis, IN 46234

>

> Cell

> Fax

>

> 90% of Risk Management is knowing where to place the decimal point...any

> consultant can give you the other 10%(SM)

>

> This message is from pH2. This message and any attachments may contain

> legally privileged or confidential information, and are intended

only for

> the individual or entity identified above as the addressee. If you

are not

> the addressee, or if this message has been addressed to you in

error, you

> are not authorized to read, copy, or distribute this message and any

> attachments, and we ask that you please delete this message and

attachments

> (including all copies) and notify the sender by return e-mail or by

phone at

> . Delivery of this message and any attachments to any person

> other than the intended recipient(s) is not intended in any way to waive

> confidentiality or a privilege. All personal messages express views

only of

> the sender, which are not to be attributed to pH2 and may not be

copied or

> distributed without this statement.

>

>

>

> _____

>

> From: iequality [mailto:iequality ]

On Behalf

> Of Redington, Curtis

> Sent: Tuesday, June 27, 2006 8:59 AM

> To: iequality

> Subject: coil and drain pan odor

> Sensitivity: Private

>

>

>

> Group,

>

> A long standing problem with the building I work out of, along with many

> others I'm called to look at, is the chronic summer-time musty odor

coming

> from the cooling coils and/or condensate drain pan. Any

recommendations of

> products/treatments (other than ozone or UV lights, please!) that

you know

> to be successful - especially for the cooling coils?

>

> Curtis Redington, RS

> Environmental Quality Specialist

> City of Wichita Dept. of Environmental Health

> Wichita KS

>

[Guest guest]

A long standing

problem with the building I work out of, along with many others I'm

called to look at, is the chronic summer-time musty odor coming from the

cooling coils and/or condensate drain pan. Any recommendations of

products/treatments (other than ozone or UV lights, please!) that you

know to be successful - especially for the cooling coils?

Ok, I am going to ask the question, since it hasn't been asked so

far. Did you try to clean the coil and pan? Coils need to be

cleaned at least annually, unless the filtration system is REALY

decent. And, BTW, do you have plans to make improvements in the

filtration system so that the problem doesn't reoccur if you should get

rid of the odor problem?

I am also going to also suggest another possible problem that is not

coil-esque. The insulation in the air handler as well as in the

ductwork might also be contaminated with mold. Some molds have the

ability to go into a dormant or lower activity state when they become

dry. They don't die out completely. When adequate moisture is

once again supplied, as it is when the air handler goes into cooling

mode, these molds flourish again. Older insulative liners, coupled

with poor filtration that supplied spores and food source for the molds

to grow, are great homes for mold. They tend to hold some moisture

themselves and provide nooks that provide growth areas protected from the

air stream. Set-back cycles enhance the growth because they provide

quiescent periods for mold to grow without the bother of the air

stream. Put the air handler or insulated ductwork on a roof or

other unconditioned location and you can add warmth during off cycles to

further enhance growth.

There are also some cases in older air handlers where the manufacturer

(Trane for sure) put a foam type insulation in the pan. It did not

have an even surface, forming multitudes of valleys where debris could

accumulate. I am not certain that such areas are great for most

molds, but it sure is ok for slime molds and yeasts that like really wet

conditions. These were definitely found on samples I collected from

such areas. However, I collected them back in the days when we were

just becoming aware of indoor air quality and the samples sat in a

refrigerator for a couple of weeks before being processed. (It also

had something to do with the government agency I worked for at the time

having to set up a contract to have the samples analyzed. Back

then, samples were usually analyzed by college biology departments or

individual specialists because the proliferation of labs we have today

did not exist.) So, my results were tainted. Still, some

odors could be caused by such members of the mold family.

I also want to add on the comment about the condensate drain sticking up

above the pan floor. I have also seen cases where the debris in

pans that are not regularly cleaned forms its own dam at the pipe inlet,

even if it is even with the bottom or comes out of the side of the

pan. The problem gets really set when going from cooling into

heating back into cooling modes. During cooling, the condensate

pushes the debris to the edge of the pipe inlet but just doesn't have

enough flow to push it into the pipe. When the system goes into

heating mode, the debris hardens and becomes a dam for condensate when

the system again goes into cooling mode. The funnel-shaped drain

inlets are intended to help prevent this problem and seem to work, but

that also depends on installation and upkeep factors.

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

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: mkklein68@...

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

Wouldn't it be nice if common sense were really common?

[Guest guest]

Curtis:

My recommendation....pressure wash (clean) the coils.

--

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

Geyer PE, CIH, CSP

PRESIDENT

KERNTEC Industries, Inc.

3703 Columbus Street

Bakersfield, California 93306

P

F

mgeyer@...

www.kerntecindustries.com

www.michaelgeyer.com

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

Group,

A long standing problem with the building I work out of, along with many others I'm called to look at, is the chronic summer-time musty odor coming from the cooling coils and/or condensate drain pan. Any recommendations of products/treatments (other than ozone or UV lights, please!) that you know to be successful - especially for the cooling coils?

Curtis Redington, RS

Environmental Quality Specialist

City of Wichita Dept. of Environmental Health

Wichita KS

[Guest guest]

Direct expansion (DX) coils can also have problems with

dehumidification due to the staging of the compressors with the

cooling load. On smaller systems, the compressors are either on or

off. When they are off, unconditioned outdoor air is being mixed with

and being circulated with the return air. There have been a number of

articles about this situation in the ASHRAE IAQ Journal.

Tom in St. Louis

>

>

> In a message dated 6/27/2006 4:56:29 P.M. Eastern Daylight Time,

> ph2@... writes:

>

>

>

>

> What are the coils made of aluminum, copper, ???

>

>

>

>

>

> Generally aluminum fins, copper coils, and galvanized end plates for

direct

> expansion systems. Flooded systems can use steel tubing and

fins...depends on

> the application and refrigerant used.

>

> Odors are always a service pain. Do your systems draw unconditioned

air in

> as make up air? I have found many chronic problems with systems

condensing

> outside air in the cabinets once the thermostats are satisfied .

Hence mold,

> odors and bacteria really get a hold in the insulation. Also check

the usual

> suspects drain pans, too high delta T ( belts)...

> I have used BBJ products with success but note any fogging tends to

disrupt

> the natural balance , sometimes the bad guys get stronger. UV lights

eat

> belts, wiring , motor windings, plastic drain pans, and service

people's eyes ,

> as well as destroying bacteria, in irradiated areas.

>

> If the systems are found clean ... I have had problems with one

mfg's coil.

> When they were exposed to diesel exhaust in low concentrations they

reeked

> as they corroded . There again is a fresh air intake problem.

>

> Good luck

>

> Valin

>

[Guest guest]

Matt, your suggestion to investigate the insulation is a good one.

"The insulation in the air handler as well as in the ductwork might

also be contaminated with mold."

I had a rooftop unit that served a single classroom that drove me nuts

trying to figure out what caused an odor that smelled slightly metallic

sometimes and other times like an overheated computer. We deep

cleaned the carpet four times--no change. Replaced carpet with tiles--no

change. Removed some of the funishings--no change. Pressure cleaned

the guts of the HVAC unit--no change. When I put my nose up to the insulation

in the HVAC unit I could not smell the odor. Even when I put some of the

insulation in a jar for three days, then opened it for a whiff--nada. But out of

desperation I tore all of the insulation out of the unit. Bingo! Odor gone.

Miles Athey, PhD

ACS

Ritzville, WA

[Guest guest]

Mathew,

Good questions. Yes, in both the buildings I'm currently working with, maintenance staff have cleaned the pans and coils. The pan cleaning was probably more thorough than the coil cleaning. Filtration is also pretty good - better than average efficiency pleated filters (although with typical bypass between filters in the racks). Interestingly, these buildings are served by multiple air handlers, but the odors seem to be associated with certain "problem" units in each of the buildings. No apparent problems (or noticeably different conditions) at the outdoor air intakes. Also, no visually apparent fungal problems with the insulation up or downstream of the cooling coils. Nasal appraisal of the pans, insulation, and coils points to the coils as the odor source. In the building I work out of, the problem is an every summer issue (same unit affecting the same part of the building). In the other building (that happens to be next door), the odor problem first showed up several weeks ago. Odors persist despite a variety of products that have been experimentally added to the pans. Usually just results in a more "pleasant" odor somewhat masking the dirty sock smell. Not really any more effective than putting cologne on a billy goat.

Thanks for everyone's comments and suggestions. I didn't really expect any easy answers, but the discussion has certainly been worthwhile.

Curtis

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of Matt KleinSent: Wednesday, June 28, 2006 8:33 AMTo: iequality Subject: Re: coil and drain pan odor

A long standing problem with the building I work out of, along with many others I'm called to look at, is the chronic summer-time musty odor coming from the cooling coils and/or condensate drain pan. Any recommendations of products/treatments (other than ozone or UV lights, please!) that you know to be successful - especially for the cooling coils? Ok, I am going to ask the question, since it hasn't been asked so far. Did you try to clean the coil and pan? Coils need to be cleaned at least annually, unless the filtration system is REALY decent. And, BTW, do you have plans to make improvements in the filtration system so that the problem doesn't reoccur if you should get rid of the odor problem?I am also going to also suggest another possible problem that is not coil-esque. The insulation in the air handler as well as in the ductwork might also be contaminated with mold. Some molds have the ability to go into a dormant or lower activity state when they become dry. They don't die out completely. When adequate moisture is once again supplied, as it is when the air handler goes into cooling mode, these molds flourish again. Older insulative liners, coupled with poor filtration that supplied spores and food source for the molds to grow, are great homes for mold. They tend to hold some moisture themselves and provide nooks that provide growth areas protected from the air stream. Set-back cycles enhance the growth because they provide quiescent periods for mold to grow without the bother of the air stream. Put the air handler or insulated ductwork on a roof or other unconditioned location and you can add warmth during off cycles to further enhance growth.There are also some cases in older air handlers where the manufacturer (Trane for sure) put a foam type insulation in the pan. It did not have an even surface, forming multitudes of valleys where debris could accumulate. I am not certain that such areas are great for most molds, but it sure is ok for slime molds and yeasts that like really wet conditions. These were definitely found on samples I collected from such areas. However, I collected them back in the days when we were just becoming aware of indoor air quality and the samples sat in a refrigerator for a couple of weeks before being processed. (It also had something to do with the government agency I worked for at the time having to set up a contract to have the samples analyzed. Back then, samples were usually analyzed by college biology departments or individual specialists because the proliferation of labs we have today did not exist.) So, my results were tainted. Still, some odors could be caused by such members of the mold family. I also want to add on the comment about the condensate drain sticking up above the pan floor. I have also seen cases where the debris in pans that are not regularly cleaned forms its own dam at the pipe inlet, even if it is even with the bottom or comes out of the side of the pan. The problem gets really set when going from cooling into heating back into cooling modes. During cooling, the condensate pushes the debris to the edge of the pipe inlet but just doesn't have enough flow to push it into the pipe. When the system goes into heating mode, the debris hardens and becomes a dam for condensate when the system again goes into cooling mode. The funnel-shaped drain inlets are intended to help prevent this problem and seem to work, but that also depends on installation and upkeep factors.

******************************************************If what is written looks too stupid to be written by me, I disclaim it. Onthe 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, MBAIndoor Air Quality Solutions, Inc.2523 SR 133Bethel, OH 45106-0007VOICE: FAX: (with notice)E-mail: mkklein68@...*******************************************************Wouldn't it be nice if common sense were really common?