Fermentation chiller

[mysterio]

I've decided to brew a Ken Schwartz fermentation chiller, 'cause i've noticed brews fermented in the lower ambient temps of my porch taste much better:

http://home.elp.rr.com/brewbeer/chiller/chiller.PDF

I've noticed some of the ones you guys have made on other threads, I just need a couple of tips on the componants as my electrical know-how is pretty basic. I think I'm looking for a 12V fan - will any cheapo PC fan do? And can anyone point me in the direction of the kind of adapter I'm looking for?

Also, will this sort of room thermostat do? I'm hoping to do the whole thing for under £20...:

http://cgi.ebay.co.uk/ROOM-HEATING-THER ... 0044660386

Thanks!

[jasonaustin]

I think I'm looking for a 12V fan - will any cheapo PC fan do?

Yes

And can anyone point me in the direction of the kind of adapter I'm looking for?

Do you mean the power supply? 12v DC. I had one lying around. Doesn't need to be 12v - less just means the fan runs slower.

The thermostat needs to be SPDT (single pole, double throw). What this means is that it doesn't simply break the circuit when the temperature drops, but switches power to a different circuit (which you will connect to your fan). Sometimes they (suitable stats) are described as being suitable for cooling circuits also. I can't tell from the link whether this is suitable, sorry.

[noby]

I made one of these, and since then I've dismantled it again, as I chanced upon a free fridge. A PC fan is perfect for it. The thermostat also seems fine.
When I did use mine I often didn't use the electrics, as the box alone held a steady temp.

With ridged insulation (kingspan) and an old saw they're pretty simple to make.

[Andy]

Lidl were selling 12v PSU's for £2.99 last week, your local store *may* have some left. I bought one

[mysterio]

I have a few hours to kill this afternoon so I'll check out Lidl...

[mysterio]

I'm having trouble getting my head around this,

The PC fans i've been looking at have a 4 pin connector to fit to a computer PSU, how would I go about connecting this to a DC adapter? Also the DC adapters I've looked at just have one connector.

Is it a case of isolating the negative and positive wires on the fan and doing the same on the adapter and connecting them together somehow?

[eskimobob]

The PC fans i've been looking at have a 4 pin connector to fit to a computer PSU, how would I go about connecting this to a DC adapter? Also the DC adapters I've looked at just have one connector.

Is it a case of isolating the negative and positive wires on the fan and doing the same on the adapter and connecting them together somehow?

Hmmm. Original PC CPU fans simply had two wires (+ and -) and they were often wired into a 4 pin connector to allow you to connect it to the same connections that connect to the hard disk or floppy disk.

Later ones often had three wires on a small connector that plugs directly into the motherboard so the motherboard could read and possibly adjust (via PWM) the fan speed.

I've not come across a 4 wire fan myself but if you can post a photo of the fan and connector I'm sure we can work it out.

It may be that the 4 pin connector is simply to allow easy connection into the standard supply connections that power the hard drives. Put a pic up and things will be clearer.

[Andy]

It may be that the 4 pin connector is simply to allow easy connection into the standard supply connections that power the hard drives. Put a pic up and things will be clearer.

I'd imagine you're bang on the money there EB, probably just the "standard" 4 pin connector with only 2 wired up.