Vent hood

[Roger]

So I'm about to install my vent hood and I was wondering what are the advantages to having it close to the boil pot or high above it. Will it be more efficient the closer it is? Or does it make more sense to have lots of head space? Its a 680CFM range hood 30" wide. Its going to be right against the exterior wall so the fewer holes for experimentation the better! I was thinking 18" above it to leave room for my immersion chiller. Any feedback would be great I plan on installing it very soon.
 

[Chris Craig]

I'd say, get it as close as you can practically get it.  What about your HLT?

[Roger]

The hlt is right beside the bk I'm not too concerned about the amount of steam coming from my hlt the hood is 30" ant the kettles aer 16 the amount of steam it creates should get sucked away. Or am I missing something!
I wanted to keep the hood over the bk mostly due to all the steam it creates also I have a lid for thr hlt.

[Chris Craig]

The HLT won't generate much steam.  You're not boiling in it.  The closer to the kettle the hood is, the more of the steam it will catch.  You could even consider leaving your chiller in the kettle the entire brew.  Just a thought...

[JohnQ]

My HLT is nowhere near my Vent Hood, it doesn't create a problem at all.
My BK is 14" from the lowest trim on the fan hood, but I don't need to put in a chiller.
JQ

[Roger]

It's up now I decided to go with 18"  above the kettles.  Thanks for the feedback gentlemen! 

[fakr]

at 680CFM you'll have no issues, even 24" above I'd say....

One word of warning...with that many CFM, your hood will create major negative pressure in the house\building so your brewery will get very hot in the summer, and very cold in the winter.  Could cause some bad condensation issues around windows, doors, recepticles, etc.

Real good idea to install an intake from the outside close to the exhaust...like underneath your brew table.

I found this out when I completely smoked out my garage when I turned the fan on with a little fire in the wood stove.  The fan sucked air down my chimney and into the garage...Mine is a 450CFM and way more than enough to exaust a 30GAL kettle at full boil.

[Chris Craig]

Good point fakr! If you done have an intake close by, you'll need to open a window if your house is fairly air tight.

[fakr]

A nearby window would be ideal.  I'll have to crack my door open this winter and freeze ....or cut another hole through the wall...

[Roger]

I don't think I'll put another hole in the wall but I do have a window about 6 feet away from the hood so I'll just crack a window while I'm brewing.

[JohnQ]

Guys who were around for the first Mash Occur will remember what happened when I had my fan installed in the main floor brewery...Just had the discharge vent hanging out the nearby window.  When I turned the fan on, the return air coming back in through the same window was enough to fly a kite in!
Had to cover the window around the discharge with plastic, duct tape it to the wall and it would bulge in as hard as it could.
I used to let all the cracks in the house provide my makeup air. Opening a window 6 feet away is probably a better idea, but you will likely be surprised how much air is coming in.
JQ

[Roger]

Thanks for the tip John. I have a lot of windows to choose from luckily it's summer and there is always a window open somewhere.