Insulating damper to prevent condensation

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  #1  
Old 03-16-19, 07:21 AM
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Insulating damper to prevent condensation

I had a duct cleaning company clean all my attic AC ductwork last year. They didn't do a very good job putting everything back together, so the result is that I had a lot of condensation where they did a lousy job taping seams back up. It is metal rectangular plenum with flex ducts leading to each room. This is our 3rd winter in this house and condensation was not an issue the first 2 winters before the ducts were cleaned.

The ductwork is old (30 years approx.) and has seen better days, so now I'm going to re-insulate the plenum with duct wrap and replace all the flex ducts with new, making sure to apply mastic to all joints on the plenum first and use zip ties with tensioner tool to hold the flex duct in place.

My question involves the dampers that are on the flex branches - they are a source of condensation because the metal is slightly exposed so the damper can be adjusted. I know that I won't need to adjust them very often, so how do I ensure they don't sweat in the winter? Just cover them with more insulation? I was thinking of doing that and securing it gently with zip ties rather than foil tape.

The existing dampers are in the middle of the flex duct - I plan on moving them to where the flex comes off of the plenum.
 
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Old 03-18-19, 05:58 AM
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Adjust them to desired airflow then insulate over them. We normally keep the handle sticking out so you can find it easily but you know the location of them so hide them if you like.
 
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Old 03-18-19, 07:18 AM
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Do I need to seal the insulation around the handle with foil tape to prevent cold air from touching the handle?
 
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Old 03-18-19, 08:18 AM
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Yes everything must have FSK tape on it.
 
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Old 03-18-19, 11:30 AM
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Thanks very much for confirming!
 
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