Fermentation Room

So I have this space under our basement stairs. It is 38.5" wide and is probably 10ft deep. It has a useful depth of about 6ft. I thought there was a floor drain, but it is just a sump hole. I guess you put a pump or something in there. I'm wondering if I insulated this room and made a proper vapor barrier if a small 5000 BTU AC unit would hold it at fermentation temps. I could buy a condensation pump to remove any condensation from the AC unit. As a matter of fact, there are two condensation lines running through this space overhead. I wonder if I could pull another hose through the same space. I have a book on building walk-in wine cellars and it goes into a lot of detail about vapor barriers and insulation. The best part about the space there is already an outlet in there on the left side.

So does anyone have any experience with a space like this?

Uninsulated you need about 800 BTU's for general a/c (that's about 20 degrees below outside temps). If you insulate, vapor barrier, put window unit on shelf high up with the condensor end outside this space etc. I could see you getting the room temp lower than 20 degree differential. The only real problems are condensate, (You would definitely need to pump/pipe it somewhere), newer high efficiency model window units use this to help remove heat build up but can breed mold spores, and temp control. May need to use a separate temp control like the ones used for using a frig/freezer for a fermentation chamber. Of course all beer fermenting in this chamber at the same time will be roughly the same temp +/- a few degrees. Depending on what stage of fermentation. I would say it is definitely do able. I've considered doing the same thing at my house. Never got around to doing it for a ton of different reasons unrelated to brewing. Let me know how you make out. Good luck.
Cheers
Kev

I have a 48" square, 9' tall room setup like this. Walls are insulatedand then ccoveredwwith 1" foam, and sealed. I use a home Depot 5000 btu ac Window unit with two temp controllers to keep the room at 46 degrees.

I use one temp controller to set the room temp. The second controllerturns off the acompressor when the evaporator coils get below 28f. This keeps the ac unit from freezing up.

Thanks guys. One would think a basement being underground would stay a lot cooler. But for some reason, in summer, ours gets quite humid...much more than any other part of the house. It is completely finished with it's own separate HVAC system. But if we did not have a dehumidifier in the HVAC room, it would be very humid in there. I also keep three ceiling fans running 24/7 for air movement. We recently removed a wall to open it up a bit and I hope that creates more air flow. As for the room under the stairs, it would be perfect since I have a keezer directly across from it. If I want to keep the keezer filled this summer, I have to be able to brew, so I need something for fermenting. The window AC idea is probably not going to work because other than this little room, the basement is 100% finished space. We have a second fridge in the garage but that is for extra food storage and it's too cold for ales. I may just do something with a small mini-fridge in that space or the garage.

If keeping your keezer full is your aim, the money may be better spent going to 10 gallon batches, with a full sized freezer (chest or upright) for temp control.

Quick question what temp are you trying to achieve?
Cheers,
Kev

I normally ferment ales around 68F. I also cold crash them before kegging. My goal is to avoid lifting 10gal fermenters into a chest freezer. I'm 52 with degenerative discs and use a shop crane to lift my mash tun in the garage. I'll probably just buy another fridge for our garage or build some type of ferm chamber for the garage. I'll probably buy a new fridge and use the one we currently have in the garage for beer stuff. I won't buy a used one: been there done that and had to pay someone to haul it away after it broke in two months.

The small space under the stairs just seemed like a nice spot for fermentation if I could control the temp. We had a walk-in wine cellar in our previous home that was temperature and humidity controlled with a Vinotemp cooling unit. I could do that again but that means $1000 for the cooling unit plus all the panels and floor treatment. Our basement is 100% finished space with a large dedicated cinema and a game room. If I were to do anything related to brewing in the basement, it would have to be hidden or on the high-end side. My keezer was lucky to get a corner.

Here's a thought. If there is a supply and return air trunk duct that you could tap into and bring that air into the area under your stairs. The big question is if you can bring a small insulated duct about 4" over to the area without upsetting the finished area of your basement. Like in a drop ceiling or through a wall depending where the trunk duct is. Then vapor barrier and insulate. Maybe more cost effective. Also might be able to get that are down to the 68 degree mark depending on how cool your basement gets when the a/c is running. The supply duct is more important than the return unless you "zone" that area with it's own t-stat. If you are still playing with the idea I will ask my co- workers what their thoughts are about it are. But I will need to know what temp your basement gets down to on a hot summers day. I am in the hvac trade. You probably won't be able to get the space cold enough to cold crash, but you may be able to achieve fermentation temps. Let me know.
Cheers,
Kev

The basement (terrace level as they call it around here) has it's own HVAC system. I keep it at 68 in winter and 76 in summer. Three sides are under ground and one side is daylight. In summer, the dehumidifier runs a lot down there. The window AC would have been great if there was a way to vent the exhaust and condensate, but that won't happen. I may look for a deal on another wine cellar chiller. They are kinda like window units but made for this type of installation.

Jamil used a small AC unit for his walk in in California and the differential was far greater than 20 deg. The key is properly insulating the area and making it air tight. You can bypass or remove the thermostat on the AC and replace it with your own. So long as you run the fan all the time or most of the time you will not freeze over the unit. Jamil got away with using a $100 AC for 5 years and that kept his room down into the 30's IIRC.

http://www.mrmalty.com/brewstuff.php

So in your house if you did it right you could insulate it and maybe even partition it off so one side is cold storage and the other is fermentation. Just a thought.

Cheers!

No doubt an AC unit will work. I've seen too many examples of that. There is also the coolbot controller that really works well and keeps them from freezing. It still won't work in my closet under the stairs. The basement is finished space except this little storage closet and I can't point the rear of an AC unit into my basement hallway or my office. The exhaust and condensation have to go somewhere. I live in a golf community and an AC uint sticking out the window is just begging for HOA sanctions So I have abandoned that plan.

Plan B: I'm buying a 10 cu ft fridge at Home Depot. At $400, that is cheaper than buying an AC unit, insulation, vapor barrier and something to cover up the barrier and insulation inside the unfinished closet.

Cool, good luck.
Cheers,
Kev

Ah crap, I went to HD last night to buy a 10 cu ft fridge and while a nice "little" unit, it is just too freakin small. I could never get two fermenters inside. At $400, it was a pretty good buy and takes up less space than a chest freezer. April is basically here and it will start to warm up. Now that I have a keezer, I need to brew more than just the winter months to keep the thing full. Looks like I'll be building some sort of fermentation chamber to custom fit my brewing area in the garage. I'm also back to using an AC unit. At least I can run a condensation drain outside from my garage.