Temp controlled brewing cabinet.

Try the Home Brew Digest for this type information. I typed in "site:hbd.org insulated brewing cabinets" on Google and found several references to what you seek. Bill Frazier Olathe, Kansas USA

Hi Bill,

There is an amount of related info but not quite what I'm after. I'm aiming at a miniature version of what I imagine commercial wineries may use.

What I've found is some fairly crude contraptions dealing with old refridgerators.

What I am in the process of attempting is a microcontroller system that had a resolution down to 1/100th of a degree C. My aim, particularly with wine, is to limit temperature flucuations to within 1 degree C.

In addition to all this, I will be logging the temperatures from 4 temperature sensors (brew temp, chamber air temp, heater/cooler tank temp and room temp) to a PC for use in developing some simple algorithms. These being to give some intelligence to the device enabling it to predict which way to influence the temperature and to what degree to prevent over-correcting.

It's a bit difficult to fully describe things without posting some very large messages.

Mike

I dont' think the Peltier devices are terribly effective. I haven't studied them though.

The cooling mechanism must overcome heat coming from the must itself, and the process of fermentation does generate heat, as well as heat coming through the insulation.

Because fermentation generates heat there will be a different temperature at the middle of the must versus the sides. I presume one of your temperature sensors will be imersed near the middle for data gathering there.

This sounds like an interesting project. Keep us posted . . .

Chris

From memory their are about 85% efficient. Info is available at

The peltier device that I have has about a 65w heating/cooling rating. I'm hoping that this will be enough but they're fairly cheap so, in theory, I can just add more. The insulation is 50mm (2") thick and the cabinet will be inside and out of direct sunlight so solar gain shouldn't be an issue ...but time will tell.

Apart from spiritwash fermentation with Turbo Yeast, I'm hoping the heat generated from wine/beer fermentation won't be too violent or excessive to be kept under control.

At the moment I just have a sensor sandwiched between the side of a couple of 23l (6 US gal) carboys and some polystyrene. One carboy is sitting in the open and the other is in a 18mm (3/4") polystyrene enclosure. This is to get a feel for things and to generate some usefull data for software development/testing. It's possible to waterproof a sensor with some heat-shrink but I haven't done that at this stage.

Am waiting on an 8-relay kit (currently out of stock) to complete the parts requirement.

I should have some honey from a bee keeper uncle arriving soon so the first test brew is likely to be mead. Just need to go searching for a suitable mead recipie....

Mike

I have been thinking same. In my apartment there is something like 30 C during summers and 25 C during winters so temperatures are absolutely too high especially for fast fermenting wines and beers.

I wouldn't use MDF as it don't handle spills very well. I think that I will use plywood or board made by laminating about 50 mm wood pieces (sorry, I don't know it's name in english).

Fermentation releases energy. 2 grams of sugar (8 kcal) yields 1 gram of alcohol (7 kcal) (12.5% of energy of sugar released) so with 8 kilos of sugar and total fermentation 0.125*8000*4000*4.19 joules will be released. If a peltier element can transfer 50 W (J/s) it will take about 190 days to get rid of the heat generated (I hope there is a mistake in my maths). I am going to use ice to cool.

Here is a nice plan of a fermentation chiller made from extruded polystyrene foam.

seismo malm

I don't know about your math (didn't check it) but you'd need a _huge_ Peltier cooler to handle that big a volume - especially with an active heat source (a fermenter) in it. My eyeball estimation says forget the Peltier. You need either a real refrigeration system or ice. Better still, just buy a chest type freezer and put a temperature controller on it. Then you don't have to build anything. You can also use it as a freezer when you're not using it for winemaking.

Tom S

Thanks for the formula. It looks like I may need to use Mother Nature 'assist' and tailor what I brew to suit the seasons. i.e. cooler brews in winter and warmer ones in summer. There is the thought of having a large body of water plumbed into the thing which is selectively exposed to the elements. Possibly using ice in it at the start when fermentation is most vigorous.

Your thoughts on MDF are valid and I'll have to make sure that I seal things very well to avoid swelling etc. I think the word you were looking for was plywood.

A few people have suggested using a freezer as the cooling source. Problem being that it's outside my meagre budget ...plus I have this habit of doing things the difficult way (pigheaded? me? ).

Mike

Yup but impoverished me can't afford to splash out on a freezer. It'd be nice to have but alas....

Plus it'd take all the fun (frustration?) out of the project.

Mike

So go find a used one that someone's getting rid of. It'll be cheaper than spending time building a monstrosity that won't do the job in the end.

You'll soon find that winemaking itself is capable of providing sufficient frustration to keep you happy (busy?).

Tom S

I'm pretty sure a 65W peltier is not going to get you anywhere at all. They were first used to cool nuclear powered submarines because they have no moving parts to make noise, nuclear power plants provide a whole lot of energy and the ocean is a pretty sizable heat sink.

Remember you have a hot and cold side too, so whatever you cool you have to have a way to get rid of the waste heat on that side too. It might do a quart well, not gallons.

I would agree with Tom, your time might be better spend finding a used refrigerator or freezer. I use an old refrigerator with a tweaked thermostat, the whole thing was free. I just plug it in and pray the compressor turns over when I need it...

My background is instrumentation and control so if you want some advice on controls I can probably help. Just email me.

Joe

cheaper than

I used about ten years ago a old (free) chest freezer and a timer with quite good success. Of course I had to check the temperature daily but the problematic time period (main fermentation) lasts only a few days so that isn't a problem. After that I have moved three times and will propably move again in a few years and getting rid of extra freezer is expensive (at least here in finland). Commercial temperature controls exists (for example see

and are pretty easy to use.

I think that I am making a small cabinet that holds a 22 liter carboy from plywood and using ice to cool it. I think that I will use a 12 V fan with a selfmade control to keep temperature even. It is quite easy to build a "temperature controller" from a LM317 and a thermistor.

seismo malm

You should think more like 0-30C since you'll want to be down just above freezing at certain times for both wine stabilization and beer lagering. Miker

The device I have (PELT2 at this URL

) has a large fan assisted heatsink. I was planning on mounting it through the side of the cabinet. The appeal was it's simplicity, price and the fact that it could heat as well. The cabinet was also to serve for bulk storage of brews that had fermented and needed to be kept at a temperature that was, at times, above ambient. I don't think a fridge can be made to do that without something like a heatpad?

I may end up having to do the fridge thing but... Another part of the project was for the practice with microcontrollers, sensors & robotics. I'm planning on starting a degree that is in the field of instrumentation & control. Am not sure at this stage whether it'll be a 3 year Systems Electronics or a 4 year Mechatronics.

Do you have the formulae for things thermal? Seismo posted one which was a bit scary with regards my plans. 190 days to disapate the heat from 8kg of sugar fermenting .

Could be that the cabinet will only be suitable as a wine cellar type device if that?

Thanks to everyone so far for your advice & comments. I hope that I haven't appeared unappreciative. I haven't been ignoring the advice, just being a big stubborn and reluctant to abandon the peltier & cabinet idea. ...Plus I jumped the gun a bit and already have the parts.

Regards Mike

..... and drunk

Actually, it would be more like -3 or -4C on the low end if you want to cold stabilize effectively.

Pp

Oops, you're right. I usually cold stabilize at about 27F = -2.8C, and lager (for a short period) at around 33F = 0.6C

Mike,

I suffer from the same affliction.

Try here, they have a free software package to help you calculate the heat load too. I suspect you will need a lot of these to do what you want, but see what it comes out to. Remember Peltiers can only do so much, somewhere they will specify a delta T, that's the practical limit across the device, hot side to cold. The link follows:

Joe

You should check my maths, I rejected the peltier device myself after a very hasty calculations. If you want to play with microcontrollers how about using both ice and a peltier? You can't get very low temperatures with that kind of system but you can definitely get lower or higher than ambient temperatures that way. That way you would use ice to absorb heat released from main fermentation and a peltier later to keep temperature even.

seismo malm

The next brew is going to be my first attempt at a beer kit. It says to run between 20 - 25C so I'll need to heat (summer has definitely finished here!). I use an old aquarium, water heater and pump for that :-)

I read that PDF on 'Son of Fermentation Chiller'. It uses the same thickness of foam I have which is reassuring. It also uses a fan system as a secondary control that I had in mind.

I think you're right about having to use ice for the main fermentation and hope the peltier will handle the rest. I'm considering maybe using up to 4 of the peltier devices (out of desperation) but I'll get the thing running with the one I have and gauge things from there.

I think I need to find a book that deals with physics and brewing. I faintly recall being taught at school the amount of energy it takes to raise 1 litre of water by 1C but that was many many moons ago. I assume that alcohol requires a different amount of energy?

Mike