Water in bathroom vent ductwork


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Old 12-13-09, 05:45 AM
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Water in bathroom vent ductwork

I noticed this morning that I have a large amount of water in my bathroom vent ductwork. We have a 50CFM fan that runs approximately 20 ft and vents out the side of our house. Could my fan not be strong enough?
 
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Old 12-13-09, 05:57 AM
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Two steps needed.
one: Should be a solid pipe, no flex, and sloped to the outside in case of condensation.
two: It needs to be extremely well insulated to prevent condensation.

With all of the warm moist air from a bathroom, this is a common occurrence.

Bud
 
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Old 12-13-09, 06:25 AM
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Thanks for the reply. As far as insulation, just lay batt insulation over the pipe?
 
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Old 12-13-09, 07:42 AM
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Air moves freely through fiberglass so I would (if metal with seams) seal the pipes and wrap them in insulation. PVC works also. Then bury them. There are some mineral wool insulations that block air flow. BUT, if fiberglass is what is available, just use a lot.

Bud
 
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Old 12-13-09, 12:33 PM
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50 cfm is small even for the smallest bathrooms. Id get at least an 80 cfm unit. Bath fan must run for at least 20 minutes after showering to remove RH. If this is done water in duct should go away.
 
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Old 12-14-09, 04:13 PM
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Thanks all. So, if my fan were too small would it have a hard time pushing the moisture out of the house?
 
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Old 12-14-09, 04:33 PM
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The bigger fan and the delay off of 20 minutes will help to dry the bathroom and dry the duct. I would still recommend the other changes so any moisture will drain to the outside and hopefully not form in the first place.

They have switches with adjustable off timers built in. Turns on normally, but when you turn it off, it continues for a preset time interval.

Bud
 
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Old 12-14-09, 07:01 PM
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If you have an older 50, the ducting may only be 3" instead of the recommended 4"?

Be safe, Gary
 
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Old 12-18-09, 12:52 PM
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Thanks for all of the replies! The first thing I need to explore is empyting this water in a safe way. i dont want to spill it on the isulation/drywall.

After that I will go for the insulation idea. Cover the duct up and make sure it is insulated well. Then Ill likely install a new fan; something a little larger. The fan that is in there is only a couple years old but I think Id benefit from something bigger. I also like the idea of a timer switch.

The one thing I wont be able to do it make the duct slope I dont think I have the clearance to make such a long run with the duct and get it out of the opening. Hopefully the insulation will help.
 
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Old 01-07-10, 08:04 AM
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One additional question here. I went up to remove the water and the flexible duct tore. Luckily I was ready for such an occurance. Now I am left with a flexible duct that is slightly too short to fit the vent. The vent is basically a dryer vent with a 12" long or so 4" duct that the flexible stuff connects to. So, my question, how should I got about connecting the flexible up? Is it possible to get a peice of rigid duct that can connect from the vent to flexible or should I forgoe this and purchase a whole new peice of flexible duct?

I would like to do rigid ductwork the whole way and slope it down but I dont see this as an option due to the location of the vents and ceiling height.
 
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Old 01-07-10, 09:42 AM
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Rigid is better, plastic (pvc pipe) or metal. I like to minimize the amount of flex.

Bud
 
 

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