[philm63]

New system showed up last week from High Gravity - gonna do my 5-gallon batches in the basement now - all electric! Got a condensate hood on the way, and I've been pouring over the requirements for ventilation to be sure I duct this hood the right way.

The system is a 3-vessel HERMS on a 5' x 2' stainless table so... I am having a 5' x 2' stainless hood made to match! My pots will sit inside these specs so capture should not be an issue, and the fan that will show up on my doorstep tomorrow is a Vortex S-800 inline 700+ cfm fan unit with a separate speed control. My duct riser will be 8" so all ducting will also be 8", straight rigid smooth ducting - mechanical codes and such. Short run (10' max) and only one 90 from the top of the hood straight out to the wall.

The crux of my question is this: Must I vent to the outside or can I vent to a wall just inside my garage door, and have that garage door open during venting? I'm talking maybe 18" from the garage door opening.

It's really the difference between crowding a space that already has a dryer duct and a fresh air intake just outside that same garage door - there's enough room to add an 8" wall vent there, but if I could put it just inside the garage door, that would be easier - no holes in the exterior wall.

Code requires any forced ventilation (that is required ventilation) shall vent outside, and then there are the usual constraints as to where, how high, etc. This is to prevent such ducted air from entering a dwelling, but does that also mean a garage space?

A garage space is not an occupied space - technically - so one could interpret that code requirement to make an allowance for venting condensate into a garage space that is open to the outside world.

Or am I asking for trouble here?

[Gary Glass]

I have a 2-vessel 10 gallon electric system from High Gravity in my basement.  I have a hood with a similar CFM (700 or 750, I can't remember).  It vents outside, but I never have it running at anything higher than the lowest fan setting.  I live in Colorado where we have very dry air, so you may need more exhaust power than I do. 

I don't know if it would be to code, but venting to the garage with the door open would probable be okay for the amount of vapor you are generating with your 5 gallon system.

[rburrelli]

You speak of code requirements.  If you are having this inspected then contact your local code department to get the definition of a living space and ask them to be sure.  Anything we tell you will not matter.

[philm63]

Good point. Code came into the equation because that is essentially what I do for a living, but for electrical safety to UL, CSA and IEC standards and the electric code; I really do not have any practical experience with the mechanical codes, but I'm sure there are some creative interpretations out there.

The house could conceivably be inspected in the future should I decide to have an appraisal, or if I decide to sell the house - I certainly would not want a permanent fixture to be discovered during such an inspection unless I was sure it met all applicable codes. I could ask some local inspectors - I'm sure they're around as there is plenty of new builds going in around here.

[BrewBama]

If you’ll be 18” from an open space why not simply extend the duct that 18”?


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[Visor]

   It's been about 15 years since I did any pleasure reading of the mechanical codes, but I know the circulating air intakes must be located at least 10' away from, or 3' higher than the nearest exhaust discharge, unless this has been changed, which I doubt.
   Based on past experience, I'd almost guarantee that if you let your local code authority know about this project, they will require that you obtain a building permit and have an inspection. Since you have a lot of experience dealing with codes, my suggestion is pick up a current copy of the Uniform or International Mechanical Codes, depending on which one is in effect in your locale, and get smartified about vents and venting. It might require a couple hours of your time, bit it aint exactly rocket science, especially if the IMC is used as it generally is simpler and a bit less stringent than the UMC.

[MNWayne]

Do it right the first time. Run the duct to the outside. Some day you may wish to brew with the garage door closed. If you ever try to sell the house and have a vent terminating into the garage, then it's just one more thing you have to correct for the sale or take a reduction of selling price.

[philm63]

It really boiled down (a bit too quickly) to me not wanting to add another 90 in the duct run and instead just stopping at the interior garage wall. I'm ducting through a crawl space in the basement to the garage, and while I believe the codes will require venting to the outside, I thought perhaps some creative interpretation of the codes was in order.

I see we have (essential) consensus in that I should run it to the outside instead of stopping short at the garage interior wall. I'll just need to add a 90 at that garage wall and poke a hole in the exterior wall and put my wall cap there where it should be - venting to the outside. I also confirmed the second of the two existing wall caps near that same location are both exhaust vents (dryer and bathroom) so no intakes on that wall - we're good to go.

Thanks to all for your input - much appreciated.

[chinaski]

Sounds like you did what you thought you could do safely.  I think its always good to understand the intent of the code to ensure that you are not missing something vital to safety or longevity of your home.  Despite what some might think, codes don't exist to be a PITA but have an intent to them.

[Visor]

    Realize that any single item in a building code and every OSHA or MSHA rule resulted from at least one death, and significant ventilation shortcomings can kill you just as quickly and just as dead as faulty wiring. You'll be glad in the end that you done it right.

[Kevin]

Use a steam slayer condenser and don't worry about vent hoods, ducting etc.

https://www.brewhardware.com/product_p/steamslayer.htm

[Frankenbrew]

Use a steam slayer condenser and don't worry about vent hoods, ducting etc.

https://www.brewhardware.com/product_p/steamslayer.htm

This^^^^^!

[Visor]

   One more thing you might want to think about is make-up air, any air exhausted from a structure must of necessity be replaced from outside the structure. Using the fan you listed, running at full capacity it will do one complete air change in a 10'x10'x8' room in a little over a minute, at 400 cfm you'll get an air change every two minutes. Depending on how airtight your home is, the make-up air will come from infiltration, deliberately opening doors or windows, or by backdrafting of other venting devices or fuel burning appliances if you have any. FWIW.