Looking for thoughts on a small combined keezer/fermentation chamber.

I'm in an apartment right now without a whole lot of extra room for brewing.

I'd really like a little more control over my fermenting temperatures, since in the summer, the temps are higher than I want, and in the winter it gets colder than the yeast will like, and I'm unwilling to temperature control the entire apartment more than I do right now (we're fairly frugal and tend to just shut the heat off at night, letting the house drop pretty low, or in the summer we turn the AC off during the day and it gets very warm).

I would also like to eventually be able to keg my beer.

However, I really can't be putting more than one compact freezer/refrigerator unit anywhere in the house. As it is, it will be a little bit of a stretch but I am justifying it because we'll get the guest room bathtub back

I'm rattling around an idea in my head of buying a 5 cu. ft. freezer and partitioning it into two sections using insulation, a "hot side" and a "cold side".

I know this has been done with much larger units, but I am wondering if there are any brilliant ideas in this forum on how to do it with a smaller unit. For the hot side, I'd have to insulate all the way around to keep the wall with the cooling coils from cooling the fermenter. I'm thinking cutting a small hole in the insulation and installing a fan hooked up to the temperature controller might provide my cooling air into the fermentation chamber. I can use a fermwrap or similar to heat it when necessary.

Suggestions on types of insulation? Thoughts on doing this? Is this asking for a headache? I was assuming I could put the keg on the compressor hump and use the main chamber for the fermenter.

Well, I really like the idea. I'm currently running a keezer with a 4 keg capacity (two taps currently installed) and a fermentation heating/cooling chamber built as an insulated extension from a dorm fridge. However, I'm moving in about six months, and these will stay here with my current brewing partner. So I've started to sketch out plans for my new setup, and had recently worked myself around to this idea.

I think the fundamental question is whether or not it's possible to make a "box within a box" design in a chest freezer and not totally destroy the efficiency of the device. You need to keep half of the space at 40F for your serving kegs, and the fermentation chamber part would ideally have a range between about 55F and 73F, though if your brewing habits are like mine, most of that time would be spent around 68F. This is where I'd really like one of the people on the forum who are much smarter than me to step in and help with the numbers. It's pretty trivial to imagine making an R-8 or higher insulated box out of insulation sheathing, but I'm just not sure what heating that space will do to the rest of the freezer.

It would require two controllers. At least something "smart" enough to not cycle your freezer to death and a cheap thermostat for the heating side.

Moisture is a potential problem here. Always something of an issue in keezers, and now you're adding fermenting beer to the equation. Maybe you can actually run a blow-off tube through your collar and outside the freezer entirely.

Fermwrap or heating pad or some other resistor is a sensible choice for heating. In my fermentation chamber I've used a small space heater with good results. It's an easy way to get heat as well as air circulation. One random thought is that I wonder if this is a job for a peltier heater/cooler? I can imagine an insulated box, hot side in/cold side out to the freezer, with fans running on both sides. Just a thought.

Sorry my reply is longer on ideas than actual information or experience. Hopefully more fully stating the problem will encourage some replies.