Direct Brew Kettle Ventilation - No Hood

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Chemkrafty

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I thought I would post here since most of the ventilation threads apply to coming indoors with electric brewing as I am doing. Currently I am just hijacking the kitchen like back in the day with a basic extract on the stove. It got me thinking how to remove the moisture if I move to the basement.

I see lots of folks install hoods above the brewing area and that requires a ton of air flow to capture a good portion of the moisture. I was thinking about industrial brewing and how they can be covered and use a port to vent the moisture.

SOOOO...what I was thinking is why not attach a flex hose the BK lid creating the vent for the boil. An additional hole could be created for makeup air to come in. You would still capture the DMS and blow that off and also capture the ,oisture directly and remove that. For the few times you need to remove it to stir, add hops, etc, it should not generate enough moisture to be a problem.

Anyone try this? I would love to hear whether or not anyone has made something like this work.
 
How would you keep the condensate from dripping back off the vent tube into the boil? That tube would get nasty pretty quickly and cleaning might be difficult.

Good point...I wonder how the big guys do it? I would think its possible to mitigate that if the vent dips down right away, making the low point NOT the kettle. I'm sure there's some way to make it easier to clean.

I just see hoods as being inefficient. I'll have to see if I can find a book on industrial brewing equipment to see how they manage this.
 
I'd still put a blower in-line to get that air moving. It would just require a smaller unit and be more focused.
 
I don't know why a smaller "hood" directly on the kettle won't work.

I'm doing something similar. I just this weekend fabbed up a cone to go on a 4"->6" expander. The cone is 6" at the top to fit on the expander, 15" at the bottom to be as wide as the keggle, and 7" tall. I'm using a smaller squirrel cage blower to pull air through it. I'll either have it in intimate contact with the keggle, (it fits JUST inside the rim with the handles on it), or an inch or two above. My thoughts were the same as yours - big industrial kettles have conical tops that go into vents, why not mine?

As for condensation, I'm hoping it won't be a huge problem. With such a concentrated flow of steam and air, the ducting should heat up quickly, meaning the steam won't be likely to condense much on it especially with a high amount of forced air flow, (on a hood, there's a lot more surface area, so it doesn't heat up as much, stays cool, and condenses water back down). I'm thinking it won't be an issue....and I can always run the fan for 30 minutes or so after I chill (or while I chill), to remove any excess moisture from the system.
 
I would think if your hood/ cover was slightly larger than your pot (maybe 1" diameter) then your condensation would fall outside the pot and you would have a place for makeup air to come from. As for cleaning I wouldnt think it would be too bad as long as its smooth. The large "off the shelf" brew houses the hood is also jacketed with steam so they dont condence.
 
Great ideas... I am actually liking the idea of the slightly larger conical top to eliminate the condensation issue and allow for makeup air. That may be the ticket versus a huge overhead hood. I bet you can run significantly lower CFM with a direct draw system than the overhead hood and save some $$ on the fan...especially if the makeup air is flowing up and around the BK directing steam into the system.
 
What atlest some pro systems (the one at my work) use is a cooling system in the vent hood. The stack is a upside down J shape. A short rise out of the kettle, a horizontal run till clear of the kettle side, and then the stack drops to about a foot off the floor (about a drop of 8 feet. Inside the stack are cooling coils that are feed with cold water. The cool air is less dense than the steam creating a pressure differential and a draw from the kettle. This gets rid of the steam and turns (most of it) into water that the floor drains take care of.
Cleaning is a bit of a hassle, but it is simple, no electricity and the steam is gone for good.
 
Sure, why not. If you do go horizontal pretty quickly, any condensate can be collected rather than having it run down your inverted funnel. Something like a 12" to 8", then 8" to 6" duct reducers followed by a 6" elbow. Figure out a way to add a hose barb there at the bottom. A blower outside pulling a negative pressure would probably even help you boil off with reduced power, maybe. I don't think you need any makeup air. Think about the expansion when water turns to steam. 1:2500 ratio.
 
Here's what I just made:
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Fits pretty well right on top, I'm going to make an arm so it can swing out of the way.
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I've got a blower that'll exhaust it through the dryer vent on the right.
M2eD7l.jpg


That's a 4"x6" reducer on top, I used a sheet of 18" x 30" sheet metal to make the cone, found an online template to calculate how to cut it to get the dimensions I wanted.
 
remember that when you are pumping 100's of CFM of air outside, it has to be made up from somewhere. in the dead of winter, that is going to be in the form of very cold outside air being sucked in thru every crack in your house. you want an exhaust system that has as low a CFM as possible while still removing the amount of water vapor that boils off. you really dont need a 500CFM hood for that.
 
shortyjacobs said:
Here's what I just made:

Fits pretty well right on top, I'm going to make an arm so it can swing out of the way.

I've got a blower that'll exhaust it through the dryer vent on the right.

That's a 4"x6" reducer on top, I used a sheet of 18" x 30" sheet metal to make the cone, found an online template to calculate how to cut it to get the dimensions I wanted.

How do you have your brewing exhaust tied in to your dryer exhaust? Do you just disconnect from dryer/connect to brewing? I've thought about a similar system but always baulk at how to tap into the existing exhaust without causing cross flow/poor venting issues.
 
remember that when you are pumping 100's of CFM of air outside, it has to be made up from somewhere. in the dead of winter, that is going to be in the form of very cold outside air being sucked in thru every crack in your house.
Proper venting should have a make-up air vent, not rely on cracks around the house. Ideally you don't want to vent out all the heated (or cooled) house air to the outside as that's a waste of energy. Ideally you want the brewing room to be enclosed with a sealed door so that the make-up air comes from the make-up duct that pulls from the outside (that's what I do).

Kal
 
How do you have your brewing exhaust tied in to your dryer exhaust? Do you just disconnect from dryer/connect to brewing? I've thought about a similar system but always baulk at how to tap into the existing exhaust without causing cross flow/poor venting issues.

See the white thing on the dryer vent line in one of my pics? It's a lint cleanout quick disconnect thing, I think 8 bucks at Menards. I bought two of them, although I really need 1.5 of them, (two male parts, one each for the dryer and the exhaust from my kettle, and one female part for the connection to the vent). I just disconnect the dryer, and connect my kettle vent for brewing days, (already have to unplug the dryer to get power for the rig, so there's a nice symmetry there).

I considered using a Y and a bunch of butterfly valves so I wouldn't have to unplug one and plug the other in, but it looked like it would be expensive and I'd risk blasting the inside of my dryer with steam, which could cause all kinds of issues if it condensed into there, (dryers handle moist air, not puddles of water).

(Edit: here's the disconnect: http://www.amazon.com/dp/B001AHASUO/?tag=skimlinks_replacement-20 )

Proper venting should have a make-up air vent, not rely on cracks around the house. Ideally you don't want to vent out all the heated (or cooled) house air to the outside as that's a waste of energy. Ideally you want the brewing room to be enclosed with a sealed door so that the make-up air comes from the make-up duct that pulls from the outside (that's what I do).

Kal

Yup, my laundry room closes, (not really seals, but whatever), and on the left edge of my pictures you can see a big black duct. That's the make-up air duct for the gas furnace and water heater that's a few inches out of frame on the left. Figure it will work equally well for make-up air on brewdays.
 
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Yup, my laundry room closes, (not really seals, but whatever), and on the left edge of my pictures you can see a big black duct. That's the make-up air duct for the gas furnace and water heater that's a few inches out of frame on the left. Figure it will work equally well for make-up air on brewdays.
Yup! That'll work!

Kal
 
I also use those lent disconnects and it makes switching out the vents a snap. I used to curse it every time I was switching it out trying to use clamps.
 
Any idea if having a conical vent system similar to the one in shortyjacobs pics would increase the internal heat of the kettle assist boiling efficiency? I was just considering trying to hack a similar set up for my stove top brewing in an attempt to loose less heat from the exposed surface area on top of the pot and hopefully allow me to more easily achieve and maintain a vigorous boil.
 
Fid said:
Any idea if having a conical vent system similar to the one in shortyjacobs pics would increase the internal heat of the kettle assist boiling efficiency? I was just considering trying to hack a similar set up for my stove top brewing in an attempt to loose less heat from the exposed surface area on top of the pot and hopefully allow me to more easily achieve and maintain a vigorous boil.

My setup will have a blower sucking air and steam out, which should actually increase the amount of energy required for boil.

Loss of heat due to radiant, connective,and evaporative methods is aided with venting, especially forced venting. The only thing I could see helping you is the passive "inverted J tube" mentioned earlier in this thread, but even then I'm not sure... Might help you, might hinder you...
 
What atlest some pro systems (the one at my work) use is a cooling system in the vent hood. The stack is a upside down J shape. A short rise out of the kettle, a horizontal run till clear of the kettle side, and then the stack drops to about a foot off the floor (about a drop of 8 feet. Inside the stack are cooling coils that are feed with cold water. The cool air is less dense than the steam creating a pressure differential and a draw from the kettle. This gets rid of the steam and turns (most of it) into water that the floor drains take care of.
Cleaning is a bit of a hassle, but it is simple, no electricity and the steam is gone for good.

Interesting concept and I like the simplicity of it. The only variable is cooling water flow. I wonder how much water and what sort of temps are necessary to get this to work...might have to break out some of my old chem eng math for this one to see if its even feasible on the small scale. I'm guessing with industrial cooling water it just loops back to the chiller though, whereas on the homebrewer scale it would just get wasted or need to be collected for use in the washing machine or something. I doubt the cold basement is enough cooling surface area!
 
Interesting concept and I like the simplicity of it. The only variable is cooling water flow. I wonder how much water and what sort of temps are necessary to get this to work...might have to break out some of my old chem eng math for this one to see if its even feasible on the small scale. I'm guessing with industrial cooling water it just loops back to the chiller though, whereas on the homebrewer scale it would just get wasted or need to be collected for use in the washing machine or something. I doubt the cold basement is enough cooling surface area!

Energy to condense 1.5 gallons of steam is 11900 kJ. Energy in melting 1 kg ice is 334 kJ. Damn, you need over 35 kg of ice, or over 78 lbs, if you were to use it in a recirculating ice bath with a small pump. So much for that brilliant idea. :drunk:
 
Chemkrafty said:
Interesting concept and I like the simplicity of it. The only variable is cooling water flow. I wonder how much water and what sort of temps are necessary to get this to work...might have to break out some of my old chem eng math for this one to see if its even feasible on the small scale. I'm guessing with industrial cooling water it just loops back to the chiller though, whereas on the homebrewer scale it would just get wasted or need to be collected for use in the washing machine or something. I doubt the cold basement is enough cooling surface area!

We just use tap water and it also gets dumped on the floor...I would guess 5 gal in the whole boil
 
100_4306.jpg


Mine works well with no fan. The pressure differential creates a draft that evacuates all the steam. I need to add a door for hop additions.
 
wow... that looks like a lot of moisture on the outside of your pot... did you have a boil over or is that how much the hood drips?

PS that is a kick ass hood how did you make that?
 
Yeah that's the other reason for a door is to watch for hot break, I had a wicked boil over, hence the towel. Once it starts drafting, there's very little condensation.

I had it made at a sheetmetal shop, it was kinda pricey.
 
100_4306.jpg


Mine works well with no fan. The pressure differential creates a draft that evacuates all the steam. I need to add a door for hop additions.

Have you done some pilsner type brews?
No issues with DMS or anything?

I am considering something similar but have been jumping between a closely attached cone hood like this and a reducer/expander with an inline fan. Trouble is, pretty sure galvanized metal isn't the way to go with this kind of hood. I assume you used a thin sheet of stainless?
 
Good point...I wonder how the big guys do it? I would think its possible to mitigate that if the vent dips down right away, making the low point NOT the kettle. I'm sure there's some way to make it easier to clean.

I just see hoods as being inefficient. I'll have to see if I can find a book on industrial brewing equipment to see how they manage this.
The big guys use a design similar to the steam slayer just on a bigger scale. I'm sure that's where the steam slayer idea came from.
 
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