Advice/experience with steam venting in basement brewery

[jamorgan3777]

I am finally pulling the trigger on building out a dedicated brew space and am working on the ventilation. Going full electric BIAB 5 gallon with maybe a separate 10 gallon option later. I think I have a good idea how I want the plumbing and electrical, but I am less sure about the ventilation.

I want to be able to use ratchet/pulley to raise and drain the grains so I am thinking how to combine that with a hood/vent. My idea is to have a "side pull" vent. See poor txt graphic below.

| |
| |
L<- Vapor

^ ^ ^
|...........|
|...........|
| Kettle |
|______|

That would leave the top open for the pulley system. What I am imagining is something similar to the vents on an "island cooktop" if you know what I mean. Those ones that pop up from the side and draw smoke and vapors from the range across to the side except build a larger one with decent flow (powering it with a 400CFM 6" duct fan).

What I was wondering was if anyone had any experience with this or had tried this. I have read many threads about building/piecing together various hoods, but have not seen anything like this.

On one level I think it should work to draw most of the vapor away at the point of origin, on a different level (please correct me if I am wrong here) I think people get way too fired up about water vapor from boil off. Many activities happen in your house all the time that put way more steam into the air than a 5 gallon (or even 10 gallon) brew session (e.g. 3-4 15min showers, a full day of home canning , etc.).

On another level, I feel that if venting is needed, why do I need it right at the source. The shower vent in our bathroom works well and is many feet from the shower (source). As long as I have adequate turnover of the air in the room, condensation or high humidity from a brew day should not be an issue.

Any basement brewery veterans (or anyone else ) please let me know your thoughts. I am at the "stud walls" phase so changing plans now is a lot easier than its going to be in a month or so.

Thanks!

 

[dyqik]

It depends on how hard you are going to boil. If you keep boil-off to <10% of your volume, then you don't need much venting. I'm using a 4" vent and 6" vent fan (yes, I know this is wasteful), with it drawing through the side of a shallow storage box screwed to my basement rafters (could easily attach a pulley inside the "hood" there). That pulls all the steam out easily at less than maximum speed with a 0.75gal/hr boil off rate. I don't get condensation, even on the cold water pipe just above a little to the right of the kettle.

However, condensation forms in the fan unit, so I've had to let that drip into something - usually the mash tun which is waiting to be emptied.

 

[Braufessor]

On one level I think it should work to draw most of the vapor away at the point of origin, on a different level (please correct me if I am wrong here) I think people get way too fired up about water vapor from boil off. Many activities happen in your house all the time that put way more steam into the air than a 5 gallon (or even 10 gallon) brew session (e.g. 3-4 15min showers, a full day of home canning , etc.).

I agree with you in regard to people getting overly worked up about the steam...... Showering FOR SURE puts more steam in the air in our house than brewing does..... People don't put in industrial level venting for that.

I have the benefit in my house that I have a walk out basement - so, this is my brew room - benefit of a window. I also did put a modest vent fan in the wall (we build our house from scratch 18 years ago and I was planning this as a brew room.) To be honest, I basically never even use the vent fan at all.) I usually/often crack the window open at the top 1-2 inches. Not always though. I am heating 3 vessels throughout the process. I have 10 gallon kettles, 6-6.5 gallons at finish of boil. I boil off 1-1.25 gallons/hour in the boil kettle.

I have been brewing for 18 years in this room. For the last 6 years I have been brewing 50-70 batches per year. I have had zero problems with the steam/moisture at this point. Your situation and results may vary or be different - but I have had no issues with my situation.

 

[mongoose33]

I'm going to throw a little Wisconsin advice at you, though Braufessor's NE Iowa experience isn't far off at one level.

Two key elements of moisture are damage to insulation/structure, and mold. I would submit it is in your interest to keep moisture at as low levels as you can. Once you have damage or, worse, mold, remediation is hugely costly to say nothing of the inconvenience and health issues attending to it.

If--if--your space is well sealed, i.e., there is solid vapor barrier between your interior spaces with high moisture and the insulation, you may be ok. If you have no insulation on the walls this won't matter as much (though it will w/r/t mold), but let's assume you have something like fiberglass insulation in the walls--or even above.

During cold weather there is a temperature gradient through the insulation. Exterior temp on the outside, interior temp on the inside. Within that insulation will be a temperature that is the dew point for the level of moisture presented to it from the inside moist space. At that location in the insulation the moisture will condense, making the insulation wet. That wetness will not only greatly reduce the insulation value of the insulation, it may provide a wet environment whereby the structural members like 2x4s begin to decay.

Short version: you don't want that. If your insulation is foamboard, it's impervious to vapor (it is its own vapor barrier), or spray-foam, this wouldn't matter. If your vapor barrier is perfect, i.e, plastic sheeting (sometimes known as visqueen) that is placed over batt insulation, or the insulation has a craft backing impregnated with asphalt to act as a vapor barrier, then the moisture cannot get into the insulation and cause problems.

Now, if your house is very leaky, which isn't all that unusual, such that there are cracks and such that allow the house to "ventilate" or breathe, you may be ok as well. If during the coldest stretches of the winter there is a lot of static in your house, this is a sign of such leakiness.

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Mold. You don't want that. I'd make sure I was well-ventilated regardless simply for this potentiality, especially since you're going to be doing this in a basement which already would tend toward moisture.

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Yeah, sometimes people take a lot of showers. I have exhaust fans in every bathroom where there's a shower. There's a reason code requires that, or an outside window that can be opened.

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I brew in my garage. During the winter I've struggled to figure out how to do this without dumping a lot of moisture into that space. The walls and ceiling are insulated and I do...not...want...moisture getting into those insulated spaces.

When temps are moderate enough I just open the garage doors, but when it's 10 degrees outside that's not....comfortable. Over time I developed a way to do this that works very well.

I brew in front of a window in which I've placed a box fan. I seal the sides w/ a couple of boards and the space is a sort of corridor through which air passes (including moisture) to the fan.

In order for it to work properly I needed to put a sort of "Hood" with pressedboard over where the steam rises so most of it would be pulled outside. Here's a pic. I'm not suggesting you do something like this, not at all, but if I were doing what you are, I might have a "hood" that can be folded up out of the way when using a pully, then dropped down over the kettle when you're boiling. You could do this easily with a piece of aluminum sheeting attached to hinges to the vent.



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Whatever type of venting you do, if your house is very well sealed, you'll probably need to provide some makeup air. In my setup the fan doesn't work well at all as the space is well-sealed. But if I crack the service door about an inch, it provides enough such that the steam is easily exhausted to the outside.

That's an issue when it's 10 degrees outside as, well, that makes the garage pretty darned cold, which I do not care for. So I have a Mr. Heater Convection Heater that I place near the door to warm the air entering through the cracked-open service door.

That's how I get makeup air. If your house is very leaky, that may not matter. If not, you'll probably have to crack a window.

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Anyway, if I were you, I'd fashion a hood that can swing down over your kettle when not using the pulley. But regardless, you want to get that moisture out of there as much as you can.

 

[jamorgan3777]

Thanks for all the input so far. House is relatively new and I am in the basement in an unfinished corner. I will be venting directly to the outside through a spray foam covered rim joist. I will have makeup air through the return air duct for the power hot water heater (code in our development).

Again, brewing only a couple times a month and with only an hour or two of boiling I dont see as much of a problem as 5 of us showering every day. That is a LOT more moisture and it is "managed" with a couple of air vents that run during our showers.

I totally agree with you on the mold issue. Dont want to mess with that.

Thanks again.

 

[mabrungard]

Your need to hoist the bag will limit what you can do, but you definitely need a vent to get the steam out or you will end up with a soggy environment. Locating the vent intake close to the kettle will help. Also, locating a fresh air supply duct close to your kettle to replace the air you are venting, will help avoid wasting too much of your house's AC or heating. John Blichmann authored an article in BYO on this subject less than a year ago.

 

[mirthfuldragon]

Another option would be to put the vent in the ceiling and then mount the pulley system on a set of blocks or risers 8 or 10" below the fan. Even with a a high gravity 10 gallon batch, the total lifting weight is going to be less than 100#, so as long as you are mounting it securely, it should hold the weight without issue. Think something like a pullup bar.

 

[daveMN]

I E-BIAB with a similar 440 cfm fan like you described. I have the fan off to the side and can hang the bag to drain. I run the heating element at 40% with the lid mostly on and boil off about a gallon per hour. The fan does a pretty good job getting the moisture out. I did some measurements and the humidity in the room goes up about 5% on a brew day. It keeps the glorious brew day smells out of the rest of the house for the most part.

View attachment 1502471024801.jpg

 

[highland_brewer]

Why not put a regular hood over top and construct a lift arm for your bag that will swing out of the way when your done. Then you can remove the bag by swinging it to the side and then swing it back flat to the wall when boiling? I have a HERMS system in my basement and have been thinking of doing something similar to what I am talking about to do small test batch biab.

Here is a photo of a lighting arm similar to my thoughts, it probably is not strong enough to lift a biab bag, but you should get the idea.

 

[highland_brewer]

Your need to hoist the bag will limit what you can do, but you definitely need a vent to get the steam out or you will end up with a soggy environment. Locating the vent intake close to the kettle will help. Also, locating a fresh air supply duct close to your kettle to replace the air you are venting, will help avoid wasting too much of your house's AC or heating. John Blichmann authored an article in BYO on this subject less than a year ago.

And a recent podcast with Brad Smith..