Looks good! Nice work. Right now i'm only using a 2 gallon bucket on the hump (still haven't made a bigger reservoir from HVAC ducting like I intended), but I agree the system does great at maintaining temps, but it takes a while to bring 10 gallons of wort down 10 degrees. Thus I usually spend a bit more time chilling with my cfc to get within 3-5 degrees of pitching temps. I've also found if I have to chill more than that adding a few blocks of ice to the ferm chamber really helps add some cooling power for the initial cool, after which the water pump is sufficient to keep things rolling at your set temp.
Well this isnt going as planned so far. Ive got 10 gallons of pumpkin ale in the chamber and the system is struggling to keep temps in the low 60s where I usually ferment (last night the beer was at high krausen and was reading almost 70 and the reservoir water was in the 60s).
Some of this is my fault. I put the wort in the chamber at around 69F and expected/hoped it to cool down to pitching temp overnight
after a whole night it only got down to around 66. Not wanted to wait any longer I put a few frozen water bottles in the chamber, two frozen water bottles in the reservoir, pitched the yeast and hoped for the best.
Since fermentation started it hasnt gotten below 66 yet, the closest I got was when I added four frozen water bottles to the reservoir after about an hour the temps were down at 66.1 but soon went back up.
A few thoughts on why this isnt working so well. I would love to hear input/ideas.
1. Pump may be too small (I dont think this is the culprit. If it were I would expect the reservoir temp to still be cold i.e. the water is not transferring the heat properly).
2. Not enough exchange from the keezer to the reservoir. I have a fan blowing at the corny keg but do not have a separate pump constantly recirculating water (water only recirculates when the ferm chamber is calling for cold). That might help. I already adjusted the recirculating pump so that the input pulled from the bottom of the keg and the output dumped into the top. Didnt seem to help much.
3. Chamber is not insulated enough or is too big
Ambient temperature (~72F) is not much more than ferment temps since this is in my basement but this could be a possibility. Its 2 inches of polystyrene sandwiched with basically drywall on both sides. Inside dimensions are about 3x3x2 ft (18 cf). I also could seal up some of the very small gaps in the front panel/door but they are very very small.
Does anyone have any other ideas? I think the first/cheapest thing I can do is seal everything up better, and maybe add another skin of insulation to beef up the R-value a little bit.
My mind continues to race back to a thought I had previously
putting a second transmission cooler in the keezer and recirculating through that. This would basically give me close to 100% heat transfer, the keezer temperature controller would probably react quicker to call for the freezer to turn on, and it would take up less room in there. But if my problem is truly not enough insulation or too big of a chamber this wont really help me much.