Exhaust hood idea: blue tarp & pvc. Thoughts?

[jwb96]

So I have an idea for a hood build, wondering if anyone has tried anything like it.

Use PVC & elbows to make the bottom frame as big as you need (square for one kettle, or rectangular to fit over 2-3).

Install an inline vent fan into a square or rectangular piece of ply/mdf/etc, that matches the proportions of the frame but only large enough to fit the fan.

Use a blue tarp, with a hole in the center to go over the fan, secured to the ply/mdf (top side), draped down to the outside of the PVC frame, wrapped under the bottom, and secured (glued?) to the inside of the PVC frame. This creates your drip channel.

If you want to get really fancy, cut your PVC lengthwise for a really big channel, and add in a T somewhere you can run a drain tube from.

Suspend the whole thing through the ply/mdf.

May be something better than ply/mdf, since it will need to deal with moisture.

My though is that the pyramid shape will guide the moisture up to the fan, it will be CHEAP to build, will be lightweight.

Thinking about tackling it. Will let you know how it goes, if you don't let me know first.

Jim

 

[andrhamm]

subscribed. if you could make it collapsable for storage that would be awesome


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[jwb96]

subscribed. if you could make it collapsable for storage that would be awesome


Sent from my iPhone using Home Brew

Another benefit I was thinking of. I'd use flexible duct to connect the fan to my window, so it can all come down and pack away easily.

 

[ChrisL_]

Very interesting. I am looking to move my brewing indoors and have been looking for a cheap easy way to set up an exhaust fan.
I saw a thread where someone used one of these hung by some rope.
http://www.homedepot.com/p/Behrens-16-3-4-gal-Galvanized-Utility-Tub-3GS/100186673

In fact, I just found the thread.
https://www.homebrewtalk.com/f51/my-ghetto-basement-exhaust-hood-setup-375726/

I have also read one person who simply opened the window and put a fan in front of it and found that to be sufficient. I think he ran it for a couple of hours after brewing.

I may try that with the addition of putting up some plastic to cover the floor joist over top of my brew kettle.

I will be interested to see how your project turns out.

 

[LandoLincoln]

I found out if your inline fan is big enough, then the water vapor won't even have a chance to collect on the inside of the hood and thus you don't need to worry about drip channels, etc. The hood is nice to effectively channel the vapor to the fan, but that's about all it needs to do in my case.

I boil off about 2.75 gallons an hour and I have an 8" inline fan which pulls about 750 CFM's. My hood stays dry the whole time.

But I do get a significant amount of water that leaks from the bottom of the fan housing. Once that vapor hits the fan some of it cools enough to become water again. I estimate that I get about 12 ounces of water that leaks from my fan every brew day. Just make sure to drill a weep hole or two for the water to get out of the housing.

 

[jwb96]

I found out if your inline fan is big enough, then the water vapor won't even have a chance to collect on the inside of the hood and thus you don't need to worry about drip channels, etc. The hood is nice to effectively channel the vapor to the fan, but that's about all it needs to do in my case.

I boil off about 2.75 gallons an hour and I have an 8" inline fan which pulls about 750 CFM's. My hood stays dry the whole time.

But I do get a significant amount of water that leaks from the bottom of the fan housing. Once that vapor hits the fan some of it cools enough to become water again. I estimate that I get about 12 ounces of water that leaks from my fan every brew day. Just make sure to drill a weep hole or two for the water to get out of the housing.

Interesting. I was thinking I'd mount the fan to the hood, so it would be vertical. With flexible duct, I could basically build a trap for any condensation by just letting it sag. With rigid duct, I would slope it downhill to my window. The other way is to mount the fan away from the hood. Does anyone know if it makes much difference where the fan is placed - at the intake or output end of the duct?

 

[kwadric]

I did something similar. I built a rectangle out of the blue half inch high density styrofoam insulation from Lowes. I taped the joints with duct tape. Light weight and easy to move, but it is not collapsable like OP's idea.

 

[jwb96]

Picking up a free tarp tonight with one of Harbor Freight's coupons. This thing is just getting cheaper and cheaper. I don't have the fan yet, but with a rainy weekend I plan to build up all but the fan and report back.

 

[southwoodbrew]

If you get the right fan it should work. I bought a 6" inline fan off eBay for ~$75 shipped and built my hood out of wood for about $30. I don't see why this idea wouldn't work.

 

[wilserbrewer]

I have no issues simply placing a window fan in an open window behind and slightly above my brew kettle. If I were brewing everyday, sure a hood might be the way to go.
Running the fan for 20 to 30 minutes clears out the basement quite well. I have no concerns about the short humidity spike during the boil as the fan does a decent job but falls behind a bit, or doesn't catch all, just most.

I have thought a 55 gal. poly drum cut in half lengthwise would make a decent hood on the cheap.


Wilserbrewer
Biabags.webs.com

 

[sumbrewindude]

I have thought a 55 gal. poly drum cut in half lengthwise would make a decent hood on the cheap.

Wilserbrewer
Biabags.webs.com

That's the route I'm chasing down for my basement corner - already got a drum free from work!

 

[jwb96]

Need to grab some pics, but I brewed with my tarp hood this weekend. Expenses went something like this:
1. Tarp: $3.99 at Harbor Freight. Couldn't get in early enough to get a free one.
2. Scrap 2x4: Free. Had some laying around so skipped the PVC.
3. Gorilla Tape: $5. Hoping it holds.
4. 6" in-line duct fan: $22 at Amazon. Could have gone up to an 8" for a few dollars more, but didn't bother.
5. 4 eye hooks: $2.36 at Home Depot.
6. Cable for hanging: free. Scrap from another project.
7. 6" flexible duct: $10 at amazon.
8. 6" worm-drive clamp: $5
9. Scrap ply: free
10: Corner brackets: $3

So $50 range. Worked well - basement did not feel damp, had condensation on the window screen at the exhaust. And it's collapse-able, as intended, as well as very light. So pretty happy.

Pics coming.

 

[LandoLincoln]

Good job! This is a very reasonable alternative to building a wooden or metal hood, since we're not working around the flames and grease combo.

 

[BadWolfBrewing]

Pics?

 

[jwb96]

Here it is, in place:

Turned out to be a little overkill as my brew kettle ended up right under the window. But I had to do it . . .

Collapses to almost nothing.

For just the brew kettle, I built a square frame. I then cut a square from the tarp, after figuring out how much drop I wanted. Tape the middle of each side of the tarp to the middle of each side of the frame, work you way to the corner and fold neatly. The Gorilla Tape seems to be holding, but I might put some staples in it at some point to be safe. I also reinforced areas that would be subject to wear and weight with Gorilla Tape.

I had a scrap of plywood, so that was cut into a square, cut a hole for a union, rounded the corners to prevent tears in the tarp, and put eyehooks in the corners for hanging. My scrap was about 11" square. I used small screws from inside the duct into the ply to hold it in place.

I have basement windows that pop out by lifting them, so I ripped some 2x4 to the same dimension as the window sash, cut a rabbit and glued in a piece of MDF (what I had, not the best material though) to match the window sash size. Cut a hole, and installed the 6" inline duct fan with corner brackets. Make sure the screws don't interfere with the fan blades. Attached flexible duct with bad clamp. I don't attach the flexible duct to the hood - just let friction hold it.

Here's the window assembly in place:

So cheap, easy, light, compact. I might add hinges to opposite sides of the frame for more compact storing.

The 8" duct fans aren't much more and pull more air. If you have a longer run, might be worth it.

 

[rayf]

Have you used this yet? Any problems with condensation?

 

[Call_Me_Tex]

That looks quite good. I was expecting some horrid monstrosity. Well done Sir.

 

[jwb96]

Have you used this yet? Any problems with condensation?

Towards the end of the boil, I've gotten some dripping where steam has condensed on the duct. I wonder if the larger fan would move more air and avoid that or if there's an inherent flaw in the design. I might put a lip around the duct where it enters the hood to start with.

 

[NewBrewB]

Any idea what the cfm rating is for your fan? It should really be okay with such a short run, if it has enough juice to move the air before it condenses.

Sorry if you already said it. I skimmed the thread but didn't find anything other than the price and the fact that you got it on Amazon.

 

[schematix]

Subbed.

I have a very similar configuration where I'm building my electric set up. Almost exact same type and size window right above the BK. I had envisioned something similar to what you've put together here, but i like the use of PVC and the tarp. I would guess you don't have to vent aggressively to get the condensation out on the short pipe.

 

[augiedoggy]

I used foam board and tape to build lightweight hood and just have it over a window with a dual exhaust fan unit in the top of the window...l works very wel

 

[jwb96]

Any idea what the cfm rating is for your fan? It should really be okay with such a short run, if it has enough juice to move the air before it condenses.

Sorry if you already said it. I skimmed the thread but didn't find anything other than the price and the fact that you got it on Amazon.

It's 240 CFM: http://www.amazon.com/gp/product/B005KMTYFK/?tag=skimlinks_replacement-20

The 8" is 400: http://www.amazon.com/dp/B005KMUHWY/?tag=skimlinks_replacement-20