Request for Steam Ventillation Information

[brettwasbtd]

Similiar to Geoffm33's thread for induciton information I wanted to try to pool together some more information surronding venting of steam in electric setups. Through extensive searching I am seeing some users saying their 200cfm range hood fans are working fine, and others who state they had issues even with a 400 cfm fan.

Please try to provide the following information to help all of us out

• Pre-boil batch volume
• boil off/hr
• fan speed/type
• duct length, diameter, and bends
• hood distance from kettle

Feel free to provide any other additional information you may feel is necessary like your location, average humidity, and if you insulate your ducting.

 

[IslandLizard]

Excellent idea!

I've seen some very creative and also very simple venting solutions on HBT. The one that stuck was the guy who used a very large stainless mixing bowl as the vent hood, together with a fan and regular round ducting. That round hood is a lot easier on the head too.

Many range hoods don't even vent to the outside. They rely on filters, some with charcoal, which are obviously pretty useless.

 

[jeffmeh]

Angles and bends in the duct work are relevant also, as they reduce the cfm throughput.

 

[brettwasbtd]

Excellent idea!

I've seen some very creative and also very simple venting solutions on HBT. The one that stuck was the guy who used a very large stainless mixing bowl as the vent hood, together with a fan and regular round ducting. That round hood is a lot easier on the head too.

Many range hoods don't even vent to the outside. They rely on filters, some with charcoal, which are obviously pretty useless.

Yes! I think you are referring to this one which is very nice: Easy & Cheap Stainless Vent Hood

Angles and bends in the duct work are relevant also, as they reduce the cfm throughput.

Good call, I adjusted the 4th bullet to mention this.

 

[AnOldUR]

I'm interested in this thread because I'd like to do a hood someday, but for now I use a Vornado 1700rpm, 370cfm fan that blows over the kettle toward an open window. I get a little over 1 gallon per hour of boil-off with a 12 gallon boil. Without the fan running there's condensation build up on the wall and ceiling. With it, none.

 

[klyph]

I had this made by an hvac sheetmetal shop. It works well, requires no fan, gets about a gallon per hour boiloff. Initially there will be some condensation that runs down the inside of the cone until it heats up, but after that, it drafts well like a chimney. The main downside is I have to lift it off for hop additions, but this hasn't been enough of an issue for me to cut a door in it. Yet...

 

[deprecated]

Here is mine:

Pre-boil batch volume:
Varies.

boil off/hr:
1.75-2.00 Gallons/Hour

fan speed/type
6 Inch ValuLine Centrifugal Inline Fan (435 CFM). Link.

duct length, diameter, and bends:
Approx. 25 ft, 6" diameter with 2 90 degree bends.

hood distance from kettle:
Approx. 2.5 ft.

Additional notes:
Purchased a Hi/Lo variable speed controller. Works great and build link for fan/hood is HERE.

 

[showcow]

Please try to provide the following information to help all of us out

• Pre-boil batch volume
  
• boil off/hr
  
• fan speed/type
  
• duct length, diameter, and bends
  
• hood distance from kettle
  

Feel free to provide any other additional information you may feel is necessary like your location, average humidity, and if you insulate your ducting.

Pre boil: 7 gallons
Boil off/hr: 1 gallon
Fan: 6"inline vortex 450CFM
Ducting: 6 feet of 6", 3 feet of 4", one 90° elbow during 6" section
Hood distance: bottom of hood is 2' above top of kettle.

I'm going to make a post of my own for this, but here's my DIY vent hood. Total cost was around $75, and that includes a $40 pocket hole jig!

Frame is 1 x 3's, and box is made of 1/4" MDF. The whole thing is 4' x 2' x 2', so I bought 4 sheets of 4' x 2' MDF to minimize cutting necessary.



Here it is after paint (satin)


And here it is mounted (it isn't crooked, just a weird angle)




I've had pretty severe condensation problems around the fan. Only done one text brew (with water) and one actual batch, but i think I need to silicone the seam running down the center of the vortex fan except for the bottom. Most people leave the center mounting screw but I have it mounted vertically so that wasn't an option. Thinkin about doing a horizontal mount in the future.

 

[kal]

Pre-boil batch volume:
Typically 13.9-14.9 gallons

boil off/hr:
1.9 Gallons/Hour

fan speed/type
6 Inch Votex 452 CFM

duct length, diameter, and bends:
Approx. 8 ft, 6" diameter with 2 90 degree bends, located above my condensate hood with access doors.

hood distance from kettle:
Approx. 2 ft.

Additional notes:
Complete writeup on ventilation requirements including sizing calculations for both gas and electric can be found in my ventilation article.

Kal

 

[trussell]

I bought a cheap 190-200 cfm black Broan range hood off of Amazon. I boil right next a door that goes outside. I cut a hole in an old closet door that fits the opening when the main door is open and the vent goes through that. Using an IC3500 and last brew probably boiled a bit over a gallon per hour. Mon did a 90 min boil didn't notice much extra humidity.

 

[NewBrewB]

[*]Pre-boil batch volume (11-14 gal)

[*]boil off/hr (1.8-2gal)

[*]fan speed/type (ss 540 cfm inline vortex fan for 6" duct)

[*]duct length, diameter, and bends (hood made from a ss mixing bowl and riveted to the fan...from the top of the fan, 6" expandable dryer vent goes up vertically about 3', turns 90 degrees towards the wall, and punches through the brick exterior wall of my house. For the record, I'm sure smooth-walled vent pipe would be far more efficient than the expandable stuff but this was easy and didn't require measurements to put it in place.)

[*]hood distance from kettle (About a foot....long enough to look, stir, add hops, and never have the hood be in the way)

[*]Other comments (Used a variable speed control designed for vortex fans and I use it at low 70 % of the time, medium 25% of the time, and blast high 5% of the time to clear any overall humidity in the room since my hood is only over my BK. The room is indoor, and about 6' x 13'.

 

[tolonen]

Another helpful data point would be exposed wort surface area of your kettle. More surface area leads to a higher rate of evaporation.

I put a pot on top of my wort during boil and it decreases evaporation and energy consumed as less surface area requires less energy to make the wort boil. May be some formula that takes this into account? I'm not sure.