Ventilation options

Feurhund · Joined: 01 Feb 2011 Posts: 89

Guys looking ahead at venting this monster I was surprised, yet again at the cost of a hood and fan setup. I wanted to see what people are using to vent their systems and if there are any more economical option etc. Thanks.

MillWerks · Joined: 16 Dec 2010 Posts: 35 Location: Seattle

Hey Feurhund, I had a guy at a local sheet metal shop make a hood out of 20ga galvanized sheet metal for about $150. He took a 5' wide sheet and bent it into a large "U", so that it was 5x2x1 feet. Then they put some ends onto it with what he called a Pittsburgh roll (no welding). He also rolled all the edges so that there aren't any sharp edges.

My hood doesn't have a condensation trap, but I've brewed a few times and I haven't had any dripping. I imagine that some of the condensation is collecting in the rolled edge so that it may start to rust in a few years. I'll cross that bridge when I get to it.

I used a slightly different blower than Kal, a Fantech RVF 6xl, which is mounted outside to help reduce the fan noise. Not that it's quite with almost 400CFM pulling through the hood. All in all, I'm very happy with it.

longarmbrewing · Joined: 16 Dec 2010 Posts: 74 Location: WA

Why would you mount the CP under the hood? Aren't you concerned with the potential with condensation getting onto or into the box. I realize we went with a water resistant box but I don't see a reason to ask for issues.

MillWerks · Joined: 16 Dec 2010 Posts: 35 Location: Seattle

I had the same concerns, but I put there because of space concerns. It's hard to see in the picture, but there's a door to the left of the CP, so the only other place was over the sink. That being said, after a 90 boil and the fan going, there is no moisture to speak of on the CP.
It would be nice to have more space, but I'm just glad to have my own inside space and be out of the kitchen. Next year, I'll searching for a house with more space for the growing family. Hopefully the new place will have space for my growing brewery Mug

**kal** · Posted: Tue Mar 08, 2011 1:44 am Post subject:

I suppose you could have made the vent hood smaller - the only place it's really needed is over the boil kettle as the other two are typically covered all the time.

For what it's worth, a couple of years ago when I was testing things I had about 7 gallons of water in the boil kettle boiling away at 100%. I left the room for a while and completely forgot to turn on the ventilation! When I came back the walls were dripping wet all over the place as was the control panel. Moisture was quite litterally dripping off the panel on to the floor. Remember that my brewing room is tiny so it didn't take long to saturate the air with moisture. I was basically brewing in a sauna!

(And I don't mean some wimpy North American sauna... I mean the ones I'm used to growing up with Estonian parents/grandparents who had saunas at their cottages that were wood fired and started in the morning and heated all day so that you'd hit 180-200F and above for the sauna at night. TONS of water thrown on the rocks such that you couldn't see more than 2 feet... smacking each other with birch branches... but I digress....) Wink

So anyway, I killed the power, turned on the fan for a few minutes to clear the air, and then open up the panel and was happy to see zero moisture inside. Just like I planned it! Nobody means to get moisture inside the panel but, well, sometimes accidents happen. A lot of what I designed was exactly for that reason. In many other setups I would have shorted something out/popped a breaker/who knows what.

Kal

silverspoons · Joined: 21 Dec 2010 Posts: 555 Location: Webster NY

Check out the pics in my photo album.. i built my vent like the prototype that Kal had made out of 1" foam board, painted it and covered the outside with some scrap plexiglass. spent around $25 for the hood. I used a 4" Vortex fan instead of the 6" because i already had a 4" port in the wall.. works great and i get no moisture build up in the hood.

silverspoons

tri_joel · Joined: 05 Jan 2011 Posts: 15 Location: Northern Virginia

I would think with 400 cfm you will not have a condensation problem. The amount of condensate build up on the inside of the hood is also effected by the ambient temperature in your brew room.

If the noise is too much for you, you can increase your exhaust duct size which would decrease the turbulence, this is assuming the fan motor is not located in the room with you.

Feurhund · Joined: 01 Feb 2011 Posts: 89

MillWerks · Joined: 16 Dec 2010 Posts: 35 Location: Seattle

I located the ceiling joists and then drilled holes in the top of the hood to correspond with the joists above. I used SS #8x1 1/2" (i think) sheet metal screws. I used 3 screws per joist (joist running perpendicular to the hood) for as many joist that were under the hood. The hood was fairly rigid, so it didn't matter if there were no screws at the very ends of the hood (because the joist spacing didn't work out that way). it's still working great and I'm very happy with it. Good luck!

Feurhund · Joined: 01 Feb 2011 Posts: 89

Does anyone know how deep the hood has to be. I have low ceilings and will. Use 4" duct and fan. What is the shallowest you would go? 8 inches?, 6? Thanks

Feurhund · Joined: 01 Feb 2011 Posts: 89

Sorry to bump thread, but does anyone know how shallow you can make the hood per my above question. I am going to get quotes and need to finalize design. Again 4" duct work.

**kal** · Posted: Fri Apr 15, 2011 5:22 pm Post subject:

Feurhund · Joined: 01 Feb 2011 Posts: 89

Good advice. I will do the foam hood at 12" and then cut down to 8" then 6" and confirm it still works with my 4" vortex at full boil. I will report when done to add to the data pool.

Feurhund · Joined: 01 Feb 2011 Posts: 89

Another design question. I have no drywall in my basement ceiling and thus have open rafters. For the sake of saving space, can i make the vent hole on the top of the hood to a 90 degree piece and then place my duct in between the rafters? does this diminish the exhaust potential as it is pulling directly up in the hood and not across? Is there any other reason not to do this?
Hoping someone with an understanding of how these works can give me feedback. Thanks again.

TheZer · Joined: 26 May 2011 Posts: 2 Location: Florida

Venting from top of hood will increase capture, thus allow decrease in cfm/ft . One 90 degree duct bend will cause minimal increase in static pressure. Remember to slope your ductwork (if possible) 1" for every foot so that condensation flows back toward the hood. Pools of water in your ductwork will cause rust.