Dryer vent condensation....HELP!

[Ultrarunner]

Originally Posted by Janipoo

I know that but my question is: If the air flow is increased with the fan, will that decrease the condensation that builds up? I am just wondering if the air is forced outside than condensation wouldn't build up like now that the air isn't moving out so well.

Yes... we use fans, i.e. air movement to dry wet carpet after a pipe or roof leak.

The fan can be wired to a common bathroom timer fan switch if you don't want to make a second trip to turn it off.

[windtimber]

Originally Posted by sailordave

...The condensation is from when the dryer is off...

Well, not necessarily. You're correct that warm, moist household air can still migrate up into the cold portion of the vent line when the dryer is off, condense, and run back down. Hence your comment on keeping the fan on all the time or getting a damper of some sort to close off the vent line.

However, if the line is uninsulated and extends through a cold attic space, if its chilly enough condensation will occur even when the dryer is operating and the condensate will flow back down the vent line - particularly if it's a vertical line to the roof.

So, we're back to relocating the line or making sure it runs on the "warm" side of the insulation up to the point it immediately vents outside. If the line is on the "warm side" of things all the way to the outside vent and there's still condensation, then the run is just way too long. In that instance the booster fan may work, but why use more electricity, have a piece of equipment that can fail, and the possibility of flammable lint building up on an electric fan? Either properly insulate the vent line or reroute it so it exits the house in as short a distance as possible.

You know, if appliance installers, builders, and "scorched air" HVAC guys had ever worked with steam heating systems, they'd know how to run dryer vents so there wouldn't be this problem!

[Deubie]

I would argue condensation does not occur when the dryer is "off". I recently purchased a new dryer & have started having the same problem. I have about a 4' to 5' run of venting. I cleaned out my vent hose today because I noticed water building up in the dryer vent hose. after doing so I put another load of clothes in the dryer. I checked the dryer vent towards the end of the cycle & found several ounces of water in the hose vent hose again. I'm not sure what I'll do for a solution & when I do, I'll post again (if I remember where I found this site.

[tikki23]

lots of good info and alternatives posted above. Janipoo, are you able to post an update with what you ended up doing about your situation and how things turned out?
I'm experiences the exact same issues as those you described (long ventilation run and lots of condensation).