Ghetto Brew Box Project

[squirt in the turns]

The obsession truly has taken hold! I became the proud owner of a kegging system on Saturday. Nothing fancy just yet – 2 kegs and 1 plastic picnic tap. Of course, this has led to valuable fridge real estate being re-purposed for keg storage, leaving my fermenter homeless.

My plan is to turn the box my urn came in into an insulated brew box, pumping coolant from the fridge. I already have a (really cheap and nasty) Bestway Flowclear pool pump that I scored from Freecycle, which may or may not be up to the task. I’ll be on the look out for abandoned AC units or anything else I can use as a heat exchanger. I might see how I go with one heat exchanger in the system (inside the fridge), just pumping coolant around a really long coil of tubing that’ll be wrapped tightly around the fermenter. Or is that just an absurd idea (due to the poor thermal properties of vinyl tubing)?

Obviously there will be variation between individual setups, but what I’d like to know from anyone who has experience cooling a brew box is what are the lowest temps achievable with this method, if the cold side of the system is located in a fridge at serving temperature (8 degrees or so)? I don’t anticipate ale temps being too difficult, but do I have any hope of getting down to lager fermenting temps?

Cheers!

[Bum]

Mick (billybushcook) has made a similarish system in a dead chesty. He's posted up his build before, have a look through his posts - it might be helpful.

[billybushcook]

if the cold side of the system is located in a fridge at serving temperature (8 degrees or so)?

Cheers!

Squirt, are you a Pom?

My serving temp is 0 - 1 deg.

In answer to your question,
Your system will be unique & take some time to tune to your needs, so I can only give you temps based on my systems performance which is:-
I struggle to hold Lager temps (12 deg) once the average daily temp gets over mid twenties, Lagers in winter are no problem.
Ale temps are no problem even in mid summer.

The fridge I use to chill my circulating water is not much chop either, hense I use my Engel fridge for beer & the other is mainly for running the brew box, cold conditioning full fermenters, yeast storage & brewing equipment.

Some sugestions,
Use a large qty, of water in your resevior, (mine is just the crisper filled with water, pump & return line submerged in it) this way you will not heat it up too quickly when the pump kicks in.
One thing Ivé considered trying is putting the resevior in the freezer & using Glycol (Antifreeze) as my medium.
The only worry is that the resevior will be higher than the brew box & if I get a leak on a hose it will drain it self into my brew box.

Definately install a heat exchanger in the box as soon as you can, along with a cowling & 12 V fan from a computer.
The plastic tube coils will not be very efficient at heat transfer (as I'm sure you are aware)
The heat exchanger can be any old radiator, car heater or Air con heat exchanger, even if they have a leak, just seal it up with some Silicon or Epoxy. The unit will not be under pressure as it was in it's former life & so will not require an expensive repair to hold water.

Your pool pump might be a bit of over kill, what is its flow rate??
I use cheap little submersible pond pumps like the one in the link, shop around, the local pumping place should be able to get you one for 20 Bucks.
Mine is rated at 500L/hr & will lift a 2m head (this is important)
http://www.rockaroundtheblock.com.au/pr ... 448&cID=83
They are only about 3 inches square/cubed.


Cheers, Mick.

[SuperBroo]

Squirt, are you a Pom?

My serving temp is 0 - 1 deg

Hey Billy,
Dont go knocking high temps mate, Dr Smurto will be onto you in a flash
He likes it Pommy style too...

cheers,
Grog

[billybushcook]

Yeh, I have suspected him for some time.

Mick.

[drsmurto]

I had a barleywine last night straight from the spare room.

Was probably around 16-18C.

To those serving their beers at 0-1C, a quote from the Wychwood Brewery is required.

'What's the matter lagerboy, afraid you might taste something?'

Whilst the original intention of this quote is to take a swipe at the lager drinkers it is equally valid with those who serve any beer at near freezing temps. At 8-10C, which is where i like to serve most beers, lagers included, there is so much more flavour. I don't even drink water at 0-1C.

And yes, i do like it pommy style

[billybushcook]

Gee, the fishing is good today.

I have tried some of my Ales at that temp & they weren't bad but I really do prefer them cold.
Probably for the same reason that I like Pale Lagers & Pale Ales, short, crisp, clean flavours.
Actually, when & if I get set up to hold Lager temps all year round, I probably wouldn't bother with Ales anymore.

Signed, Lagerboy

[drsmurto]

So what do you drink around the campfire when its bone chilling cold Extracoldlagerboy?

[squirt in the turns]

Thanks Mick, that's some really useful info!

Squirt, are you a Pom?

Indeed I am! I've lived in this beautiful country for 3 years now, and been brewing for 2. Ironically, it's only since then that I've really learned to appreciate good beer. While I did enjoy a good cask ale (Ringwood brewery's Fortyniner comes to mind - reminds me of my uni days in Southampton) I was equally happy drinking over-carbonated, over-chilled megaswill like Bud (US) or Corona. I never could stomach Carling or Fosters, though.

My first and only kegged batch, TL's SNPA, is being dispensed at 8 degrees and is bloody lovely!

Right, back to the box: The pump probably is overkill with a flow rate of over 2000L/hr. Can't find specs giving the head pressure. It's also noisy, bulky and non-submersible. If I can get a decent unit like yours, Mick, for $30, it's a no-brainer. Thanks for the link. Maybe the pool pump can one day serve the purpose I originally acquired it for, and recirculate water through a wort chiller (though I'm quite happy no-chilling for now).

So in your system, your reservoir is effectively the cold-side heat exchanger - you've only got one radiator in the system?

The freezer section of my fridge is currently empty, so I'll definitely look at utilising it. With the fridge at 8, the freezer sits at -20. A water/glycol mix in the right ratio should have no problems going down to -50, which will be more efficient and put less load on the fridge. Hopefully the chemical and temperature doesn't have any harmful effect on the pump. I'll figure out some way to minimise the leak risk (line the box with something waterproof?).

I just had a brain-fart, and after doing some fridge/keg/cube tetris, I reckon I'll be able to ferment lager at my ale serving temps. In a cube. With a blowoff tube. Balanced on top of the keg. And only if I don't mind having only 1 keg in the fridge, and getting a hit of sulphur when I go to pour a beer. Hey, I warned you this was a ghetto operation!

[billybushcook]

So what do you drink around the campfire when its bone chilling cold Extracoldlagerboy?

Wild Turkey

Mick.

[billybushcook]

So in your system, your reservoir is effectively the cold-side heat exchanger - you've only got one radiator in the system?
:

Yes.

Hopefully the chemical and temperature doesn't have any harmful effect on the pump. I'll figure out some way to minimise the leak risk (line the box with something waterproof?).

The Glycol won't be a problem.
One way I had thought of getting around the temp problem was to use an "inline" pump which would be mounted outside the freezer.

Mick.

[hirns]

Squirt, google "son of fermentation chiller" chiller. These are mainly based on a concept of using PET ice bottles, but I remember seeing a few good designs using a 12v bilge pump pushing glycol throogh old automotive oil coolers and even using cheap American 12V housing thermostats to activate the pump so that you can still have a beer fridge and a temp controlled fermentation box/fridge. I will try to dig up the sight if I get a chance.

Hirns

[hirns]

Have a look at the link below. Hopefully you can gleen a couple of ideas.

Cheers

Hirns

http://forum.northernbrewer.com/viewtopic.php?t=42735

[squirt in the turns]

Thanks Mick. Inline could work, but honestly I want to put the pump in the freezer to muffle any noise, as this whole thing is kind of in my kitchen/living room.

I've decided to pretty much go with what the guy from the Northern Brewer thread did (thanks for the link, hirns). His 12v bilge pump doesn't seem to mind operating in a freezer. I'll probably get one of these:
http://cgi.ebay.com.au/12V-Submersible- ... 3f039b7a17

If it craps out at -20, well, $30 isn't a huge investment.

My plan for the cool box is to find another box that'll fit inside the urn box with a gap of a few cm each side and on the bottom, and just fill the gap with expanding foam. I'll power everything with desktop computer PSUs, which, along with 12v fans, tend to be found lying around here at work. Temp control will be via a 2nd Fridgemate.

[hirns]

Squirt,

Big W also has aquarium pumps for about $19 (240V), could be another option if you go with a second fridgemate(and they are made to run 24/7. These are probably regulated down to 12v so you could possibly modify as well. Additionally have a look at some of the computer water cooling kits on Ebay and the net. These kits have a 12v pump(you can buy just the pieces) that plugs directly into a desktop power supply unit. In addition if you go this way and have an old PC, some of the kits have a thermostat that you can control with the computer so you won't need the fridge-mate(I realise that you were only intending to use the PSU). Why not the 12v thermostat controller as suggested on the site?

Cheers Hirns

[squirt in the turns]

Hi folks. I've dragged this thread up again as I finally have all the required bits to make this happen. My question now is: what are others using for coolant in these types of systems? Note that it will only ever be run sub-zero, so pure H2O is not an option.

I was going to use a pure propylene glycol/water mix, but Craftbrewer are out of PG ATM, and at $60, it'll push what was supposed to be a ghetto project even further over budget.

Is automotive coolant acceptable? Obviously if the system ever leaks, it's way more of a hassle to deal with, but I might be able to live with that. Is it likely to contaminate beer if it just leaks all over the side of the fermenter?

Cheers.

[barrelboy]

What about anti freeze from local auto shop, just add to your water per instructions. I would put fermenter in a plastic bag therefore no direct contact with solution.
Good luck BB

[matr]

I'd use an ethylene glycol based coolant. Probably because I can get it fairly easily for nothing.

Check this chart out for the concentration % required http://www.temperaturecorporation.com/p ... ements.pdf

It would contaminate your beer if it came into contact (got into it) as it is a hazardous substance and apparently cancer causing!!! Which is great to know as I spent years with this stuff soaking into my hands..

Cheers,

[billybushcook]

I use plain old Automotive coolant (glycol) in mine to stop it freezing, works fine.
I have no issues with leaks because the pump & reseviour is lower than the heat exchanger in the brew box (pump is in bottom of beer fridge)

Cheers, mick.

[squirt in the turns]

Cheers folks. I went for standard automotive coolant - mono-ethylene glycol + green chemicals.

I reconsidered the possibility of green leaking everywhere, and decided to place the heat exchanger at the highest point in the system. As the freezer section is above the fridge, the brew box will be on top of it. I'll get a nice arm workout lifting batches into it.