Condensation on unit and ducts during winter.

[smitty18]

I was looking for input on this situation.. I installed a air handler in attic of a ranch style home about 3 years back. The home has hot water base board heat.
Every year I get a call from the home owner about a smell. the first year one run of flex pipe had about 3 gallons of water in it.. We replaced the line. told the owner to shut off all the registers so warm air will not get in to system.Next year the return had mold in it. replace the return to unit. Instructed him that he did not properly seal system. This year we are back again!! The unit has heavy condensation of water dripping off all the metal.. What am i missing here?
Smitty

[John Markl]

Is the return near the floor, or in the ceiling ?

Sounds like warm house air is condensing in the cool attic ductwork. (ok, duh)

Perhaps occasional cycling of the air handler will solve this? Thus my question about the return. If it's in the ceiling, the occasional cycling would pull warm air from the ceiling, and not be obnoxious to the home occupants.

[bullmoose]

You have an air-handler in the attic, but you have baseboard heat? Is this system in the attic an a/c only system or is it an Aquatherm type system? Just need some more info to offer any suggestions for you. Is there a boiler installed somewhere else in the home?

[mcair8]

Have you checked your static pressure? When is the condensation present, during cooling?

[teddy bear]

Ducts in cold attics get condensate on the inside unless kept warm. Surfaces that are damp for 24 hours grow mold. Fixing this is complicated. A couple hour drying cycle everyday may stop the mold. Get the wizard that installed the ducts in a cold attic to fix it for you. Regards TB

[smitty18]

@John Markl ceiling located 3 feet from a bathroom. I think which was a
mistake.
@bullmoose "Is this system in the attic an a/c only system" yes
"Aquatherm type system" no
"Is there a boiler installed somewhere else in the home" yes
basement
@mcair8 No i have not..
@teddy bear.." Get the wizard that installed the ducts in a cold attic to fix it
for you" Cant !!!

I assume what is happening the warm air is getting in to the system by vent/return even know they are turned off..The home owner feels he should not have to place bags over system vents/return every year.. In turn causing condensation in unit....recommended turning fan to circulate air in unit.. The home owner was unhappy with that due to the fan would run 24 hrs a day and raise electrical bill..

Looking for other options for this home.. I have install many of theses system over the years with out problems..Its as basic as it gets..Trying to figure what makes this home so different..

[John Markl]

Does the bathroom have a "fart fan" ?

[t527ed]

wrapping another layer of duct wrap over trunks and flex supplies solved the problem in my fathers house many years ago.

the other thing you could do is install a thermostat with the circ feature on the fan switch so the indoor blower runs occasionaly to dry out the ducts.

[IdealCo]

Are they running a humidifier in the house? Sounds like a lot of humidity must be present in the air for condensation to be forming.

[smitty18]

@John Markl Yes it does have a fan. Don't know if they really use it.
@t527ed This time it is the unit that has water on it.
@IdealCo That was something I thought of also.No they claim ..I even went as far as putting humidy gauges all with in normal range..

I will Attach a pic of the condensation. from last call over weekend.
Pic 1 Is the Aprili Air filter housing.


Pic 2 IS the Air handler in attic.Looking thought the air filter opening

Thanks everyone so far..

[teddy bear]

@John Markl
Looking for other options for this home.. I have install many of theses system over the years with out problems..Its as basic as it gets..Trying to figure what makes this home so different..

Most of these types of systems are slowly growing mold unless the homes are extremely dry. Check the ducts in all these system, most have mold growing. Regards TB

[Kevin O'Neill]

It is not that air is warm that is the problem. It is the high humidity in the house air. That air has a dewpoint that is higher than the inside surface temperature of the ducts.

Running the indoor blower on a fan cycler will help.

Insulating the april aire cabinet will help.

Running the humidifier less will help.

Putting foam blocks in the register boots and return duct in the winter will likely stop the condensation altogether. Then take them out in the spring. Read up un psychrometrics...that will explain what is happening.

Good luck.

PS send me an email, I will send you more info back. My email address is in my profile.

[ascj]

You are getting migration of air from the house through the poorly sealed and poorly insulated ductwork. The hot air rises through the vents(closing the vents is not 100% shutoff), then cools in the ductwork and air handler. When it cools you hit the dew point and you get water.

The damage is done. I'm sure the flex, ductwork, and air handler are loaded with mold.

Next time do yourself a favor and recommend a vs air handler, so they can run the fan all the time or circulate.

[seanddd]

limiting HO's use of humidifier is not an option in most cases, I would pay 2 visits every year to seal and re-open the returns and vents, FREE of charge. This may be the most economical, and also the most satisfying gesture to the HO.

[smitty18]

limiting HO's use of humidifier is not an option in most cases, I would pay 2 visits every year to seal and re-open the returns and vents, FREE of charge. This may be the most economical, and also the most satisfying gesture to the HO.

Talking about economical.. Ho wants completed new unit due to mold as seen in pic..
I was hoping to clean it some how.

[allphase]

Will running a steam humidifier on a heat pump cause mold issues?

[smitty18]

You are getting migration of air from the house through the poorly sealed and poorly insulated ductwork. The hot air rises through the vents(closing the vents is not 100% shutoff), then cools in the ductwork and air handler. When it cools you hit the dew point and you get water.

The damage is done. I'm sure the flex, ductwork, and air handler are loaded with mold.

Next time do yourself a favor and recommend a vs air handler, so they can run the fan all the time or circulate.

Yes they are full of mold.. Replacement time I believe is necessary
I was thinking of a heat pump system or putting a heating coil in the unit.
this way it will circulate warm air verse cool.

[John Markl]

Talking about economical.. Ho wants completed new unit due to mold as seen in pic..
I was hoping to clean it some how.

Is the HO willing to pay for the replacement? Was there a defect in your material and/or workmanship? Or, is the defect in the HO usage and conditions?

[smitty18]

Is the HO willing to pay for the replacement? Was there a defect in your material and/or workmanship? Or, is the defect in the HO usage and conditions?

Ho wants free system.. I offered all labor for free. and parts at cost.
I dont think there is any workmanship concern. I am to find a smart fix. So i dont have to com back every year with him...
Possible lazy HO does not want to close off registers.

[John Markl]

Ho wants free system.. I offered all labor for free. and parts at cost.
I dont think there is any workmanship concern. I am to find a smart fix. So i dont have to com back every year with him...
Possible lazy HO does not want to close off registers.

Yah, a lot of variables here.......did you spec and design the system, did the HO spec what they wanted, etc.....I'm with the others. I think the best solution is occasional (or constant low speed) fan circulation.