Humidity problems

[trimguy]

I have a planer that has a dust collection fan blowing outside my building. I'm going to upgrade the fan in the near future, while I am doing this is there something that I can do to prevent the hot, humid air from causing condensation on my pipe and on my machine? Would a flap on the end of the pipe be worth the trouble? There is about four or 5 feet of exposed pipe outside.


 

 

 

[Don P]

can you pitch the pipe out the other way.

[doc henderson]

yes, slope to the outside going downhill.  is this just in the winter?  why are you getting cooling of the exhaust enough to cause this problem?

[trimguy]

The pipe angles up to the ceiling 
 ( about 8' 4" ) then runs a crossed the ceiling to the blower and then elbows and goes out the wall. I can't really change the pipe unless I run it straight up then elbow over. The pipe on the outside angles down. I haven't been using it lately, so it's not the exhaust air. It's a conditioned space inside.

[doc henderson]

so warm humid air from outside, coming in the pipe and the cooler space in your shop condensing water on the inside of the pipe and running downhill?

[doc henderson]

so, a flapper may work.

[customsawyer]

Try sitting a trouble light inside the machine.

[tule peak timber]

Looks like a Northfield. I like the tilt down pipe idea..

[kelLOGg]

Slide a cover over the table? Won't keep condensate off the knives if that is a problem too. 

[Don P]

I like some kind of flap outside to keep hot humid air from backing into the cool pipe,  or a tiny fan exhausting your indoor air out of that pipe all the time to keep the outside from entering the pipe. Damp in the dust pipe ain't good.

[trimguy]

 

 

 
Here are pictures of the ductwork inside and outside. I guess I will try to find a flap  to go on the end of it to see if that will help. Tile peak, it is a Powermatic 221. Thank you for your help, I will let you know if a flap works. Also, I'm still open to suggestions.

[Old Greenhorn]

Arnold, that's not good and must be really annoying. First, as you say, add a closure, like a gate valve at the outside end on the duct run, maybe add a second one over the machine. In order for that process to happen, you need to have air moving in and out freely, then condensing with the temp change. Stopping the free air flow should cut the problem considerably. Lastly, I would shove a drip pan under that duct on the machine. It won't prevent corrosion issues on the blades, but it will save the table and that cleanup.
You could add a drip leg on that down sloping pipe to the machine to catch the condensate, but I think preventing it's entry in the first place is a better way to go.

[Andries]

I think Tom's advice is on the right track. 
Stopping the free flow of air in and out of the pipe when the planer isn't in use will stop the condensation from forming.
A blast gate near the wall should stop any air from moving. They are made for dust collection ductwork, so it won't cause any blockages the way that a flapper may do.
Remembering to open that blast gate will have to become a habit before turning on the planer, but it should save your planer from rusting up. 

[K-Guy]

I think the blast gate is probably the best answer but have the gate wired to the on switch for the planer so it opens on startup. You can't forget what happens automatically.

[trimguy]

Yes a blast gate. I don't know why I didn't think of that, I have them on 
my drops for the other dust collection and that would probably be easier to come up with. Thank you.

[Old Greenhorn]

Well, that's why we beat things around here at (our equivalent of) the local pub after work. ;D

[doc henderson]

are you getting moisture in the turbo separator trash can?  you could also run the planer on the inside dust collector but have to empty more often.  

[trimguy]

Not that I noticed. The planer pipe is the only one that goes outside. The trash can is in line for the other dust collection for other tools that don't produce the volume of chips that the planer does.

[trimguy]

My blast gate came in Friday, and installed it yesterday around lunchtime. It seems to have taken care of my issue, but I will keep an eye on it for a while. A while back, I was having problems with the finished product out of my planner with the advice I was given in another thread I had gotten it pretty close to right, still was not real happy with it. Today was a good day to stay out of the heat and clean up and wax the planer and with the covers off I understood the adjustments I needed to make better now I am happy with it.

 

 
Thank you.