Condensation in dryer vent line

[DL]

I noticed the other day that when my wife was doing a considerable amount of drying, that there was condensation in the dryer vent piping.

The piping comes from the upper floor, down through the main level into the basement and then goes to an exterior wall and exits our home.

I noticed dripping from the vent piping at the 90 degree turn in the basement where it comes from the upper levels.

Is this normal? Don't know that I have ever noticed this before, mainly because it is not something have ever looked for.

David

[RBM]

Sounds like the vent pipe may be to long. Check with the dryer manufacturer as to the maximum length and bends allowable for the machine. You have hot,moist air flowing through it, and the longer it is, the more opportunity it has to cool and condense

[John Grabowski]

I had a similar problem with my dryer vent passing through the attic. I insulated the duct with duct wrap and it has been fine since. You might want to make sure that your vent pipe is clean. Too much lint will absorb moisture and restrict air flow.

[DL]

Good point. I will look into it.

The day she was doing the laundry and I noticed the condensation, it was a very very cold day, which makes me think that I need to check the outside vent to see if any cold air could be getting in.

I am also thinking about purchasing a dryer vent cleaning kit to make sure that there is no major buildup of lint so that the dryer is able to properly vent.

David

[DL]

Thanks for the advice.

Being in a heated basement, I am not sure the duct wrap is necessary, though I did see a very lousy / non-existent attempt to tape the joints between the sections of vent pipe. I agree that I should make sure that the ducts have been cleaned.

David

[EXT]

In my own situation, while I did not have moisture dripping, I found that aluminium pipe draws the heat out causing condensation. The moisture inside the pipe quickly gathers lint, so much that I was having to clean out the pipes every 3 months. The 4 inch diameter tubes had about 1/2 to 3/4" of lint stuck to the tube walls.

I replaced the run (this is for an electric dryer, do not do this for a gas dryer) with 4" PVC sewer/drain pipe. I have not had to clean it out for the past 12 years. The plastic pipe holds the heat in and prevents or reduces any condensation. My idea to use PVC was based on seeing furnaces that used ABS or PVC drain pipe as a vent.

[whodat]

your dryer vent is definatly too long, no doubt about it.

[DL]

Really good idea. though it would be major surgery to replace the 16' run from the dryer upstairs (3rd level) to the basement.the basement run would be simple. How did you connect from the dryer to the PVC?

I am almost scared as to what I will find in the vent ducts when I clean them.

David

[EXT]

I used a short length of flexible vinyl tubing, just enough to allow me to make the connection and move the dryer that last few inches against the wall after I had extracted myself. Had to reduce the diameter of the PVC sewer pipe slightly to fit the vinyl tubing over it. Used a heat gun to soften the pipe and a tightened large gear clamp to shrink the diameter until it was the right size. Worked like a charm.

[CDET 14]