Day-afternoon temps have been in mid-60s; night temps in mid-40s. Shop is uninsulated, and currently at 58F, outside air temp, 53F. Supposedly, temps will hit 68F by this afternoon.
I have a side-by-side refr/freezer that holds 2 carboys, stacked, on the fridge side. I use a Johnson thermostat/controller to maintain ale/lager temps in Summer. Since temps are dropping at night, I’m thinking of hanging an incandescent (halogen, maybe?) light bulb inside to keep it warm. What watt bulb would you guess would suffice?
You should look into the reptile heating options. They make bulbs and heating cords for terrariums that are made to operate in a wet environment. I use a ReptiHeat cable which is made to heat, but not get hot to the touch (so it’s plastic safe).
I have one of the ceramic reptile lamps with the metal “safety cage” around it. I place the safety cage on a pyrex pie pan that fits perfectly onto the condenser box in my fermentation freezer. I works great and has consistently for a couple years now.
I don’t like to use a bulb, but I have (on a separate thermostat) and then I face it away from the beer to minimize heat intensity and to help screen light (my fermenters are buckets or plastic Speidels). About a 40 watt incandescent will be plenty.
Two stage controller. You could also get a separate single stage controller. If the temp is low enough you could also switch an existing controller to heat.
As Steve mentioned, two stage Ranco controller is what I use.
Somebody else mentioned light as an issue with the reptile “lamps”. The one I have is a black ceramic bulb that emits no light. To minimize radiant heat intensity on the fermenters I set the lamp cage in a pyrex pie plate which also holds the lamp securely out of the way on the condenser shelf.
Most years in south Louisiana, the cool months are January and February. It’s still not unusual to have nights where the heater runs followed by days where the AC is needed. That’s why my thermostat has an auto setting.
Even today, I use no attemperation during the cool months. I have always fermented in an unfinished basement. A basement does not change temperature rapidly. I never used to brew during the warm months, so lack of attemperation was not a problem. I used to start fermenting English-style ales in mid-September. By November, my basement was cold enough to switch over to brewing hybrids. Late December through February was lager time. In March, I brewed hybrids. By April, I was back to English-style ale, and if I brewed into late May, I would usually brew a five-gallon batch of American-style Wit with malted barely, malted wheat, Tettnanger kettle hops, sweet orange peel, coriander, and BRY 96. I enjoy brewing with the seasons even though I have a fermentation chamber today (cooling only).
Well, to be clear I use Spiedels for 1 bbl fermentation but back when we were a 3 bbl brewery I used plastic conicals with the same tape and insulation and could control 90+ gallons of beer temp the same way!
