I was going over plans for my e-brewery build in my basement with my Dad this weekend and he seems to think I will have moisture issues with boiling in my basement. I explained that I will be using ventilation with a fan but he still thinks I will have issues with my basement wood rotting. My plan was to DIY a hood and possibly tile all around the brewery so all moisture is contained. Any of you guys out there that have been brewing indoors for a while have any sign of moisture issues?
Indoor E-Brewers: Moisture Issues?
- Thread starter xsists
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I am moving towards e-brewing. It seems that the bigger setups so indeed have a big vent. I would think that at least a stove hood of some type with an external vent/fan would be important. Even when I do a small brew on my stove the house steams up. It quickly clears up since our winters are so dry, but just to say it is a LOT of water we're pumping into the air.
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I still brew in my garage because I have the same concerns your dad expressed. I think it depends on batch size and capacity of the ventilation system. I brew 35 gallon batches and routinely lose 5-7 gallons during the boil. I am sure there is a way to do this properly but for now I will be brewing in the garage.
as long as your fan is powerful enough to remove the water vapor as fast as it is evaporating, you wont have problems. if you have the vent sucking directly from the top of the kettle, you dont need nearly as much CFM of airflow as you would if you only had a hood a few feet above the kettle.
if the hood is not powerful enough or is too far away, it will be removing mostly air in the room instead of the water vapor coming from the pot.
if the hood is not powerful enough or is too far away, it will be removing mostly air in the room instead of the water vapor coming from the pot.
xsists
Well-Known Member
My whole point of moving my brewery to electric is to be inside. I cannot use my hose in the winter (as it will freeze) to chill in my garage. But even so, are you running into any moisture issues in your garage? I understand that there is a large open door, but some of that moisture has to be retained in the garage, I would think.
With the dryness of winter air, I would not be concerned with this in a garage, though there might be some condensation/freezing on some cold surfaces.
I have the same hose issue as you and this is why I am building electric, too. I am concerned about the water given off in a big brew and must come up with a solution.
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shortyjacobs
Well-Known Member
Here is my setup:
I use a dayton exhaust fan I got for $30 on ebay similar to this one:
Used Dayton 115V Blower Fan / Good Condition | eBay
The cone rests on the rim of the keggle nicely:
I've done a 1 hr test boil with absolutely no moisture escaping - the fan is actually overpowered for this, and it's pretty small, (guessing in the 100-200 CFM range, at the most, although it's not rated). Holding a lighter flame near the edge of the keggle shows there's a large negative pressure, even under full 5500W boil.
So my advice is, build a cone you can place close to the keggle, which reduces the airflow required to evacuate all moisture. A large hood is great, but requires a LOT more airflow.
I use a dayton exhaust fan I got for $30 on ebay similar to this one:
Used Dayton 115V Blower Fan / Good Condition | eBay
The cone rests on the rim of the keggle nicely:
I've done a 1 hr test boil with absolutely no moisture escaping - the fan is actually overpowered for this, and it's pretty small, (guessing in the 100-200 CFM range, at the most, although it's not rated). Holding a lighter flame near the edge of the keggle shows there's a large negative pressure, even under full 5500W boil.
So my advice is, build a cone you can place close to the keggle, which reduces the airflow required to evacuate all moisture. A large hood is great, but requires a LOT more airflow.
(I removed the images in the quote)
How does this setup effect your boil-off rate?
I'm intrigued by the idea of a hooded kettle.
shortyjacobs
Well-Known Member
No flipping clue :cross:. I'm experiencing SSR issues (see my other thread in this forum about how hot should an SSR run), and haven't been able to brew. Never measured boil off when I did my test boil...was more interested in how well the fan worked.
I'm guessing, with the fact that my fan is sucking far more than it needs to, that I may require a bit more power (75% vs 65%, for example), to keep it boiling at an acceptable rate, just going off of the idea of a covered pot of water vs. an open pot of water. I figure that the amount of energy required for a certain level of boil goes closed pot < open pot < open pot under forced ventilation....
As a ChemE though, my guess is that although I'll need a certain amount extra energy to boil at the same "vigorousness", that the boil off rate won't change. Boil off rate should be pretty closely tied with energy put into the water that goes towards vaporization of the water. The partial pressure of water vapor at the surface is negligible, in this case, since we're talking forced boiling, (for the most part, most of the boiling happens at the element, NOT at the surface of the water....we just see the surface "boiling" because of water vapor bubbling up from the element). SO, since my kettle is under forced ventilation, the heat transfer rate from water -> surroundings will be increased, and thus I'll need more power to maintain a certain level of boil. Put it this way, if you need, say 3000 watts of power to get a "good boil", and a covered pot loses 300 watts of power to the surroundings, then you need your element to put out 3300 watts to get your desired boil. An open pot may lose 500 watts to the surroundings, so you need 3500 watts total. My forced ventilation pot may lose 800 watts to the surroundings, so I need 3800 watts total. In all THREE cases, however, you're only putting 3000 watts into boiling the water, so the boil rate, and thus the boil OFF rate, is the same, (although, of course, with a covered pot a decent amount of steam will condense back down into the pot...ignore that).
Long story short - I don't expect a big change in boiloff, as long as I keep the boil rate, or how rolling a boil I have, the same.
All conjecture, at this point. Partial pressure of water vapor may play into it more than I'm assuming, and I may be full of crap.
LordUlrich
Well-Known Member
I am fairly certain that when the wort is boiled under negative pressure alot of the chemistry changes. For instance you will likely be pulling out more dms. This brings up the more important point, that it is the finished beer that matters, not specific numbers. Perhaps you don't need as much boiloff with the vacuum.
shortyjacobs
Well-Known Member
Hrm, I should have clarified negative pressure. I most likely have VERY slight negative pressure, with a decent amount of volumetric flow. It's the high flow that stops moisture from escaping. I am NOT forming any significant vacuum, and in fact I'd estimate my pressure in the keggle headspace is only a few millimeters of water less than atmospheric at best.
You're right, the volatility of things like the DMS precursors will change with pressure, as will the boiloff rate of the water....but again, I'm guessing I'm only changing the pressure in the headspace by a fraction of an atm, so again I doubt it comes into play.
Thanks for the very thorough reply. :rockin: I'm not an engineer by any means, but I think I understand most of it.
I'll be interested to hear whatever results you observe once you're able to test. I know the final beer is all that matters, but we all know the process is a big part of how the final beer turns out.
inkedfireman
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The hooded kettle is brilliant, I was searching on here to see if anyone had done it with a homebrew setup. I went on a tour of New Glarus, and realized that every professional brew kettle is topped with a cone and vented outside, no one puts up a huge hood feet above the kettle!
