Need help with exhaust system dripping

[flyfshrmn98]

I did my first brew on my new eBIAB setup yesterday and everything went great minus the exhaust system dripping about 30 min into the boil. It wasn't dripping from the hood part, but the fan and a couple joints around the fan. Its currently setup horizontally with about 24" flexible duct and an elbow between the fan and exhaust bowl and then a straight shot to the window about 12 feet away. The fan is a 6" hurricane blower fan with 430 cfm

I'm wondering if I should attempt to mount the fan vertically right about the bowl and then run 1 piece of flexible duct to the window? As of right now I don't think there is enough room above the bowl for the fan and then duct so I might have to lower everything. I don't want it much lower so I can still get the basket out of the kettle without hitting it. Also thought about siliconing all the seams on the fan

 

[ButcherBoy]

If you can get all the joints sealed it will stop the dripping, but not the condensation. The condensation will still be there, just not able to get out. I would attempt to provide a place for the condensation to drain out so it doesn't buildup and damage your blower. I've seen that happen in dryer vent systems from time to time, it is amazing how much water can build up in a vent system.

 

[daphatgrant]

I've been looking at ventilation options and haven't made it far. I'll be watching this thread.

 

[flyfshrmn98]

If you can get all the joints sealed it will stop the dripping, but not the condensation. The condensation will still be there, just not able to get out. I would attempt to provide a place for the condensation to drain out so it doesn't buildup and damage your blower. I've seen that happen in dryer vent systems from time to time, it is amazing how much water can build up in a vent system.

Do you think it would be better if the fan were mounted vertically right on top of the bowl? I drilled a small hole in the bottom of the fan during the last boil and there was no water collecting

 

[ButcherBoy]

Hmmm, not really sure. You might have to try several configurations to get something that works well. If it was me... I would eliminate the flex vent, replace it with rigid vent sloping down from the fan. Drill a hole in the low point and provide some kind of a drain hose to get rid of the condensation. Moving the blower to a vertical mount close to the origin may help keep condensation out of the blower, but if I did that I would be keeping a close eye on it until I knew for sure.

 

[Deece]

Love your hood

 

[schematix]

I've got a similar set up, with exactly the same issue. After a few minutes of boiling it pretty much drips continuously back into the pot.

When i first had the issue i did some investigation with some process mechanical engineers I work with. They said the standard procedure when dealing with steam condensation is to either allow for drainage, or to keep all the components hot enough so there is no condensation.

So I sealed the fan housing with silicone caulk. I also wrap the hood in a towel prior to brewing and it soaks up what does come of of hard to seal areas.

For your situation i'd probably seal the joints with caulk, and if you really are worrying about the water in the fan, drill a tiny hole in the bottom of the fan hosing and install a small fitting you can hook to a tube, and drain it to a bucket. Vertical installation could help too. I attached my fan directly to my hood.

 

[flyfshrmn98]

I've got a similar set up, with exactly the same issue. After a few minutes of boiling it pretty much drips continuously back into the pot.

When i first had the issue i did some investigation with some process mechanical engineers I work with. They said the standard procedure when dealing with steam condensation is to either allow for drainage, or to keep all the components hot enough so there is no condensation.

So I sealed the fan housing with silicone caulk. I also wrap the hood in a towel prior to brewing and it soaks up what does come of of hard to seal areas.

For your situation i'd probably seal the joints with caulk, and if you really are worrying about the water in the fan, drill a tiny hole in the bottom of the fan hosing and install a small fitting you can hook to a tube, and drain it to a bucket. Vertical installation could help too. I attached my fan directly to my hood.

Ive already got it all taken down so I think I'm going to try to mount the fan vertically and see what happens. Also going to silicone the fan seams and then either silicone/red guard the the duct fittings. Also building a track that I can slide the hood out of the way to swing in a pulley as well to help drain the mash.

 

[Chrisl77]

I have a long run going from my fan to where it exits my house. Instead of using that flexible foil duct stuff that doesn't even work great for dryer vents I bought some insulated flex duct for hvac. Its been there for a few years now and I have never seen a drop come from any joints. In the cold weather when I am brewing you can see the steam cloud coming from the vent outside.

 

[BrunDog]

The insulated duct might make good sense as the vapor temp will hold longer, causing less condensate to drop out of gas vapor. That said, the best cure is to make sure that your fan and vent are set up to take in lots of dry air along with the wet air. That will reduce the amount of saturated air. A weep hole at a low point is probably needed either way.

 

[steveoatley]

Tap a whole in your Fan,
add hose barb
add hose to drain

That looks like the lowest point in your system

There is were most of the water could be.....

just an idea

2 cents
Steve

 

[steveoatley]

Tap a whole in your Fan,
add hose barb
add hose to drain

That looks like the lowest point in your system

There is were most of the water could be.....

Don't bother - this solution did not help me at all
Not to hijack your thread - i was working on another solution as well.

https://www.homebrewtalk.com/showthread.php?t=570312

Steve