Thought I'd share this idea with the group. Last year, my first year making wine, I was trying to find a location in the house with a steady 60-65 degrees for secondary fermentation. The fieldstone basement was a logical choice, but it can dip down to 40 degrees in the winter, but never gets above 67 degrees in the summer. I built several "environmental chambers" out of foam insulation board.
I bought several sheets of the 1" stuff, and some foamboard liquid nails. The box is a bottom, four sides and a top that is a little over size and has cleats glued to the inside to fit it into the box. I built a thermostat-controlled electrical outlet and plugged a pair of 25 watt lightbulbs in porcelain bare-bulb fixtures into it. These fixtures should be mounted in ceiling boxes for safety. These lightbulb fixtures simply sit on the bottom of the chamber on one end. Between the carboys and the lightbulbs, I put a "baffle" of insulation board across the inside of the chamber, that is about half the height of the interior. This prevents direct light from hitting the carboy, or allowing the light bulbs to cause hot spots. The reason for having two lightbulbs is that if (when) one burns out the other will simply run twice as long and the wine will not suddenly lose temperature before I can discover the bulb is out.
Inside the box, I mounted the outdoor sensor of a digital indoor/outdoor thermometer, and mounted the display on the outside of the box, set to "outdoor".
The thermostat-controlled electrical outlet was made using a 3-gang plastic outlet box. On one side I mounted a bi-metal strip thermostat. Mercury switch thermostats must be mounted vertically, so such would have to be mounted to the inside wall of the box. The thermostat is also of the house power type rather than the low-voltage type.
Inside the outlet box, the thermostat is wired in series with the outlet. The power cord from the outlet box exits the chamber box through a small hole near the bottom. Now, I can simply plug in the box and set the thermostat. The box must be 3-gang, since an outlet and thermostat will not fit well together in a double. There is a gap left between the two devices that I covered with a strip of Lucite plastic screwed to the center holes.
To experiment and calibrate the thermostat, I filled a 5 gallon carboy with water and placed it inside the box as if it were a secondary fermentation vessel of wine. Over a period of a week or two, I monitored the temperature on the indoor/outdoor thermometer display and tweaked the thermostat inside accordingly. I found that 65 degrees is actually about 62 on my thermostat.
Someday, I intend to refine this design into wooden cabinets with shelves spaced for my fermenters and carboys in their various sizes. The cabinets will be lined with this insulation, and both the thermostat and the thermometer will be built in such a was as to display to the outside. I'll have one for primary fermentation, and another for secondary.
If this design sounds interesting enough to anyone, I can post some pictures of the completed chamber.
John Price