Son of Fermentation Heater

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tmyoung

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Mar 30, 2012
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Hey folks,

I recently built a son of fermentation chiller, the weather has been hot and it seems to work great. However, fall has hit hard, and when I checked on my fermentor this morning it was a couple of degrees below temperature. I think it's time to ad heat. Has anybody done this before? My best idea is to ad a heat pad on the bottom, or use a belt heater. I think I should be able to wire either one to the temperature control circuit.

Any ideas would be appreciated.

Thanks
 
A small reptile heater worked well for me.. I've since moved on to a chest freezer, but the heater followed.

Heater1.jpg
 
I love that idea. How do you have it mounted in yours? Were you able to wire it through the thermostat? I was about about to buy a belt heater at my local homebrew shop, when I realized that the belt will stay hot for a period of time after that thermostat shuts the belt off. This period of time will be extended by how well the fermentation chamber is insulated.

I think to do this right, I'll need to set up another baffle on the other side of the fermentation chamber. I must admit, I never read through the whole write up about the Son of Fermentation Chiller, but as I understand the baffle is what makes it work so well. Because hot air rises, and cold air settles, when the fan is off, the cold air hangs out in the little pocket near the opening of the baffle. When the fan turns on, the cold air is forced up, through the opening in the dividing wall, and settles around the fermenting wort, until it warms up, rises again and is drawn back towards the ice. For this to work well, and efficiently, there should be a second baffle system, with a baffle opening at the top, and openings in the dividing wall with a fan leading to the fermentation chamber in the bottom. Unless I could find a really skinny heating element, I will need to add some length, or do something creative to my chiller.

Thanks for the tip, it really got me thinking. I only wish I had a thermostat that could automatically switch between heating and cooling now.
 
tmyoung said:
I love that idea. How do you have it mounted in yours? Were you able to wire it through the thermostat? I was about about to buy a belt heater at my local homebrew shop, when I realized that the belt will stay hot for a period of time after that thermostat shuts the belt off. This period of time will be extended by how well the fermentation chamber is insulated.

I think to do this right, I'll need to set up another baffle on the other side of the fermentation chamber. I must admit, I never read through the whole write up about the Son of Fermentation Chiller, but as I understand the baffle is what makes it work so well. Because hot air rises, and cold air settles, when the fan is off, the cold air hangs out in the little pocket near the opening of the baffle. When the fan turns on, the cold air is forced up, through the opening in the dividing wall, and settles around the fermenting wort, until it warms up, rises again and is drawn back towards the ice. For this to work well, and efficiently, there should be a second baffle system, with a baffle opening at the top, and openings in the dividing wall with a fan leading to the fermentation chamber in the bottom. Unless I could find a really skinny heating element, I will need to add some length, or do something creative to my chiller.

Thanks for the tip, it really got me thinking. I only wish I had a thermostat that could automatically switch between heating and cooling now.

Mine was a "mother of a fermentation chamber" so it's a little bit different design. You should be able to make something like that work though.

I did just use the house thermostat that I picked up from Home Depot. The cool side would just pass the 12vdc to my circulation fan seen behind the heater. The heat side would both power the fan and a relay with a 12vdc coil to send 120vac to the heater.

I do have pics, but I'm my phone at the moment and down with a case of strep throat. Maybe when I make it to my computer I'll share them with you.
 
I got one of these seedling heat mats from Amazon. Its similar to the brew belt and those sorts of things, but cheaper, and better built. I also picked up the thermostat that they sell with these. I wrap the mat around the carboy with bungie cords, and tape the temp probe to the opposite side of the carboy. The mat covers about 2/3 of the surface of my carboys... approximately??? Links below. I highly recommend!!! Plus the thermostat can be used for other things, 1000W output I think it has.

http://www.amazon.com/dp/B0001WV010/?tag=skimlinks_replacement-20
http://www.amazon.com/dp/B000NZZG3S/?tag=skimlinks_replacement-20
 
Last edited by a moderator:
Oh, and I too was trying to come up with a way to put heat in my Mother of Fermentation Box... and decided the mat was the least likely to burst into flames. Haha!
 
Well, I got pretty distracted by school, and have yet to put a heater element in my box. The term just ended, and I'm hoping to brew some beer real soon, so it's time to put the heat in. I haven't had time to act on any ideas yet, but I've thought of several over the last two month or so. Here are the ideas I had.

  1. Add another foam board chamber, similar to the ice chamber, but with the heater and the baffle oening at the top, and the openings to the main fermentation chamber at the bottom. One of the openings will need a fan. Cons: Take up more space, requires expensive foamboard.
  2. Cut holes in the side of the main fermentation chamber, run insulated ducting to a small wood box that houses a heating element and fan. Cons, take up more space, requires expensive insulated ducting, requires epensive drill bit to cut holes.
  3. Place the heater element in the upper part of the ice chamber, just behind the fan. Tape uninsulated ducting over the fan outlet, run the ducting to the lower part of the chamber, do the same for the intake side. Cons: Will require removal when the hot season comes, but probably no big deal.

I think option three is a winner for me. I feel like the outtake for the heater element need to be directed at the bottom of the camber. That is because heat rises, and I need to direct the heat to the bottom so it can heat the carboy. I think the intake for for the heater can be at the bottom or the top, but I think the bottom would be a little more efficient.

Now I just need to source the parts and figure out the wiring. I think what ever terminal I use on the thermostat for heat will need to both energize the relay and power the fan. I just need to find the heating element and pick a relay. I went to my local pet store, and could not find a heating element that was not an actual bulb. I think that's not what I'm looking for.

The relay needs to be specified for both the wattage and the voltage of the heating element as well as the amperage of the power source, which would be the DC power source that runs the fan, right? Circuits are not a strength of mine.
 
120 quart ice chest - fits three 6 gallon carboys once you remove the lid.
200 watt aquarium heater set to 72 (just in case, read below).
Aquarium water pump for under-gravel filters for circulation.
Auber PID controller set to 68 degrees.
SSR to switch the 120V to the heater.

Works like a champ - my shop is fairly constant 42 degrees in the winter, heater duty cycle is about 20%.
 
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