Electric Brewing Vent fan - HUGE leak - any help ?

[poptarts]

fair enough, I suppose it drips off the lid as well back into the pot.

 

[mongoose33]

Mongoose's dew point comments are possibly misleading. You are not concerned with the dew point temperature of the room - that is the temperature which the moisture in the ambient room will condense out (air has reached saturation). Problem is steam is already saturated, that is, at its dew point or darn near it. So any cooling (or pressure reductions) at all causes condensation, hence liquid build-up and drips.

The dew point you're concerned with is the temperature of the items (fan, ductwork, hood) that the moisture-saturated air comes in contact with. Perhaps that wasn't clear in my post, but that's the key.

It doesn't matter a whit what the air is--it matters whether the equipment temperature is below the dew point of that air. If the dew point of the air is higher, it means the equipment must be warmer in order to avoid condensation.

I have a nearly super-insulated house (well, 2/3 there ) that is so tight I have to mechanically ventilate it with an air-to-air heat exchange ventilator. By design, I might add--I had the house built, insulated and sealed it myself.

I control the humidity in the house by how much I run it the air exchanger, and depending on the temps outside, I may need to drop the inside humidity so I don't get condensation on the windows. When it's below zero, I have to take the inside humidity to an indicated 34-36 percent (I have a meter, not sure it's accurate, but it shows relative values which is all I need).

When it warms up outside, I can let the inside figure rise to 40 or 42, and I won't get window condensation.

The key point is what the temperature of the window glass is. If it's low enough, you'll get condensation. It's the temp of the glass in conjunction with the inside humidity that is the combination that produces condensation--or not.

 

[TexasWine]

Ever consider intentionally condensing the vapor that comes off the kettle? I haven't thought it through, so it may not be practical. But instead of fighting certain laws of thermodynamics you might get creative and find a way to get those laws to work for you. Not an approach I've ever seen for collecting steam from a brew kettle.

 

[BrunDog]

The dew point you're concerned with is the temperature of the items (fan, ductwork, hood) that the moisture-saturated air comes in contact with. Perhaps that wasn't clear in my post, but that's the key.

Yessir, agreed. Sorry if I misinterpreted.

 

[steveoatley]

So, if anyone is keeping track.

I tried my New 6 inch fan - with my 4 inch duct work - 2 weeks ago
Still lots of dripping - so that was a waste of time - 4 inch duct had to go !
I was creating back pressure at the 6 inch fan to 4 inch vent

The plan was to go to 6 inch all the way
1- Cut 6 inch hole in Bowl Hood - remount Bowl Hood
2- Knock out 4 inch vent in Glass Block window - put 6 inch vent in
Center that 6 inch vent on where the fan sits - straight shot out
3- 6 inch flex i duct from Bowl to Fan and Fan out the house.
4- Caulk the F*ck out of the Fan - every seam & screw hole CAULKED!
oh, and i had to lengthen the cord by 2 feet, to reach my speed control.
5- Added drain hole for Fan - so i can control where the water comes out.

Took WAY longer to get everything done than I thought
AND i spent WAY to MUCH time on a ladder, for building a Basement Brewery !
I have a very tiny space to work in - with this fan to the vent window

I did my Boil test last night - and everything went great !!
58F in basement - 37F outside temp

Yes there was some leaking/dripping
1- where the Fan connects to the duct/vent out of the house
a. very minor dripage - so slight i could not get a pic
b. going to live with it - this is the hardest connection to make because of space issues - so there will be a drip pan up there - only got 50ml after 1 hr boil
2- I had a leak at the 6 inch Duct and Bowl - seepage from the duct work
on to the top of the bowl - a lot of CAULK will fix that !
3- I want to wrap all the Duct work with Insulation - to help stabilize the temps - reduce any other condensation

I am happy enough with the results, that I am "cleared to brew"
I only had 50 ml of water come out of the fan & the drip at the connection
I only had 1 wet paper towel - from the drip on top of the bowl - that i can fix with caulk!
My first Brew i had 2 sopping wet towels at the end of the brew !!

I don't expect the Brewery to be 'dry' during a brew
But this is in my basement - and dumping 1 gallon of water into the ceiling
would surely do more damage than I can imagine.

I am now in the range of needing Make Up air
The 4 inch 190 CFM fan, would have been fine - no make up needed
But the 6 inch 460 CFM fan means I need make up air - my furnace is 10 ft from the Brew kettle.

So I am turning my unused 4 inch fan into a "Sucker" - it will suck air from outside
and dump that air near my Furnace. ( eventually there will be a wall that separates the Brewery from the Furnace )

Pics are in the Next post
and of course I am sure they will show up the wring direction.

Steve

 

[steveoatley]

Pics didn't post ??
At least they are not upside down

 

[lupulinaddict]

What do you feel was the most effective change? I think I have the same fan you have. I tried a brew yesterday with it and I had water leaking like when you started this post. I need to start making some changes and wondering if you had any advice on where is best to start? Also, what type of fitting and how did you mount it as a drip line? Is it flush on the inside of the housing?

 

[steveoatley]

lupulinaddict

I think there are a number of factors at play
Changing any one thing did improve the water problem

I was just being too cheap, and tried to use a 6 inch fan with 4 inch duct
and that was a waste of time.

1. moving the fan all the way UP to the vent - away from the Boil
- helped the most - the vapor is more likely to turn to liquid inside the fan
2. 6 inch fan = 460 CFM vs 190 CFM
- i do not know how other brewers get away with 190 CFM fans ?
- 190 just did not move enough wet air !
3. 6 inch ducts all the way threw
- i was being cheap, and trying to use the 4 inch i all ready had
- I was going from a 6 inch fan to 4 inch vent out the house
- that created back pressure, and that creates water out in the fan

I got a 1/2 inch hose barb from the Home Depot ( 3/8 inch hose )
I drilled a 1/2 inch hole in the bottom of the fan, and I ground off most of
the threads inside the fan - only 1 or 2 threads holding it in the fan
Then i caulked the heck outta it !

I only get about 25 - 50 ml of water out of the fan, when i brewed on Saturday

Atmospheric conditions will effect your water vapor

it was 40 F outside when i brewed on Saturday ( 58 F in my basement )
I bet when it's 5 F next February, i will get a lot more moisture
in my drip cup

S

 

[lupulinaddict]

Ok thanks Steve. I have 6" duct work now. I have a three vessel system so I have it branched off to the hlt too. On sat when I started to boil and get lots of water i duct tapped the hlt opening to get more suction out of the boil side. I think this week I'll try to put a damper to be able to run both sides, and boil at more suction, and try to insulated the ducting.

You mentioned moving the fan away because most moisture is created in the fan. I think I'll work on that too. My fan isn't turned 90* like yours it's parallel with the boil, but I do have some duct Elbows before the inlet of the fan. Inside those elbows it sounded like rain because I think so much water trying to get sucked up and falling back down. I thought of trying to install a drain there, but if the fan is creating the water... I'll try to move it down stream because outlet duct work has about 20'-25' of travel To outside. I'm in my garage and the fan is in the attic.

Thanks for your help Steve. Good luck!

 

[steveoatley]

Yes,

Insulating the Duct will help as well !!

I do plan on doing that....
I'd just like to get in a Brew or 2 before i do that

Kind of tired of having to fix something every time i brew.

Good Luck

S

 

[mheitt]

This is what I do... I made a 4 ft x 2ft hood out of foam board and hung it over the top of my window I brew in front of.. I open the top of my window and run a dual 12" window fan in it... I get no dripping at all this way.

augiedoggy, do you have photos of your foamboard hood? It seems like foamboard would be better than stainless steel with regard to the temp change/dew point issues.​

 

[DuncB]

Don't muck about with a hood, fit a condenser lid. Quieter, better and will save energy.