Long Term Costs of Maintaining Fermentation Temps

I haven't seen any detailed discussions about the long term costs of maintaining fermentation temps. I'm specifically interested in using stainless steel conical fermenters, and I would like to choose the best system for heating and cooling that uses the least amount of energy as possible.

Does anybody have any insight or knowledge about the matter? Would a refrigerator use more energy than wrapping the fermenter with copper and pumping liquids through it? I realize it depends on the wattage of the fridge and the wattage of the A/C unit, but I also can't calculate the effectiveness of each solution because I have no experience with them. Or maybe there is another method that is even more efficient. I would prefer not to hide the conical in a fridge, but I would if that's the most energy efficient solution.

I realize many homebrewers aren't concerned with how much energy they use, but I prefer to conserve energy where possible. I'm not concerned with the initial investment costs, only long term efficiency.

Thoughts?

Thanks!

What is the ambient temperature and how much does it fluctuate? Ales or Lagers?

I would definitely think you would be concerned about initial investment costs versus l-t efficiency. Digging a cellar versus buying a fridge...

I've got an upright freezer that I use for fermentation and lagering... I know that to maintain 34F at a 1 degree differential that it takes 16-20 minutes of cooling power every 2-3 hours. I'll have to throw my kill-a-watt on the freezer and see how many kWh it actually uses over a week.

Edit - I also forgot to mention that I haven't noticed even a small difference in my monthly electricity bills since putting it in.

What is the ambient temperature and how much does it fluctuate? Ales or Lagers?

Click to expand...

Temps between 55ºF and 90ºF, as I rarely use air conditioning, and use as little heat as possible in the winter.

River City, what size batches are you fermenting? I'm planning to do 10-15 gallon batches. Thanks for all the info!

I do about 13 gallons in a half barrel... I also found the cooling cycles a bit less often after I filled up a handful of milk jugs with water and set them in the freezer as well... I guess the extra thermal mass helps keep the internal temp stable.

That's good thinking, River City. I'll remember to do that if I choose to go the refrigerator route.

The two major factors affecting the cost of operating a fermentation chamber will be the ambient temperature and how well the chamber is insulated. Obviously, the size of the chamber will also be a factor, but those are the main ones. When the ambient temps are anywhere in the vicinity of room temperature, ie say from 60-80 deg F, the cost to run the chamber at 60 deg F +/- will be very low. Probably only a few dollars a month at the most. Taking it down to lagering temps will cost more, but even then it shouldn't be more than about $6 or so per month. I'm basing this on some monitoring I did recently on the small chest freezer I use for serving. I was surprised at how efficient it was and how little power it consumed. Working against very high or very low ambient temps will run up the costs considerably, but even then it's not very expensive to run these things. The newer units are a lot more efficient than the older models.

I'm actually keeping an eye on the brewhemoths right now, so I'm interested in seeing how they design their jacketed kettles. Should be interesting to watch. I really don't want to keep a SS conical in a fridge, though with the insulation of a fridge, the efficiency would probably be better than open coils. But, open coils might consume less power.