jbaysurfer said:
LOL...I'd put some exhaust in. Cheap as can be, but the only basements I've been in out here (west coast) are damp. I'm imagining it's damp where you live. I believe the answer is: Yes. You are inviting mold.
Sorry to dissent. You probably will be fine if you can crack a door and get a fan going. But I own, so I generally try to fix stuff the way I want it. Is there a window or vent nearby? maybe a single fan drawing air into that vent with a door cracked insures you'll have no problems?
I have to agree with this guy. If you're not boiling off much, you're probably not boiling properly.
So, on the low end, a half gallon. On the high end, let's say two. Even with "just" a half-gallon boiled off, that's still a great deal of water, and that water's gotta go somewhere, unless you live somewhere extremely dry. In my old house I'd brew in the kitchen in my 15gal Blichmann kettle. I did have a good range hood, but the best burner was at the front of the range, so part of my kettle stuck out a bit further than my hood... probably around 20% of the surface area of the kettle.
Now, since the hood sucks air, it got the vapor from more than just 80% of the kettle, but not all of it. And so, by the end of the boil, the ceiling around the hood (and part of the cabinets) would be soaked and just dripping wet. The Blichmann kettles come with a small rectangular sheet of stainless steel for use as a heat shield for the ball valve and sightgauge, which I used to solve most of the problem by standing it up on the handle and leaning against my range hood, so that the water vapor would either have to flow into the hood, or condense on the sheet.
That solved most of the issue, but not all of it. The point is that, any way you look at it, it's a LOT of water. It would soak the ceiling so bad that, as I'm building an ebrewery in the basement of my new place, I felt I had little choice for my situation but to get a commercial, 6 foot, custom-made stainless range hood. That's a little (a lot) overboard for the vast majority of brewers and circumstances - my system will be able to make ½bbl batches and have a very high boil-off rate - but a cheap off-the-shelf range hood, vented out of the house, is more than worth it for the piece of mind. My dad was a contractor that specialized in fire, floods, and mold, and mold can be a VERY serious issue. I'm not saying it's guaranteed, but if you run into a mold problem down the line, there's no doubt you'll be wishing you had spent the under-$100 (or even if it was a couple grand) and just avoided the issues.
I'm trying not to exaggerate, and the truth is that you will usually be fine. But mold is no joke, and a cheap hood costs so little, that it just seems silly to me not to do it.
