Electric Cold Box

[Punx Clever]

So, senior design for me in ME here at purdue rolled around this semester, and I managed to get a group together to build an "electric cold box." Some of you may be familiar with the cold plates sold so you can just take a coooler, put the plate and some taps on it, fill it with ice, and tailgate with your kegs. Not-so-cold beer goes into the plate, is cooled by the ice, and comes out the tap.

We decided that we would make one that required no ice. First plan focused on using peltiers, but they just didn't have the capacity to do the job... So we cannabalized a 5000 btu/hr window AC unit.

I tried to push for a bigger one, but costs were a concern.

Now, we have a device that will take 5 gallons of water from room temperature down to freezing in 40-45 mins. We are trying to take "beverage" from about room temp down to drinking temp with a 30s/pint pull time.

Pictures are forthcoming as is a detailed instruction on how to build one, and I'll be sure to keep this updated as to whether it works (I think we needed a more powerful unit myself).

 

[JKoravos]

From an enthalpy standpoint, chilling 16 oz. from 20°C to 0°C in 30s requires a heat flow rate of ~1.25 btu/s, which is equivalent to ~4500 btu/hr. You're essentially going to have to have 100% heat transfer efficiency to achieve your goal. I'm not sure that it's even possible without some serious modifications to the AC unit. Of course, everything is possible if you have enough time and money.

 

[beercity23]

BOILER UP! Love the ingenuity of Boilermaker engineers. I am a boiler, just not an engineer.

 

[Punx Clever]

WOW! Blast from the past...

As it turns out, we "won" the senior design contest with our box... here's the basics of the guts:

We later built a nice wooden cabinet to house it in.

It took root-beer from room temp down to ~40F or so as it was being poured... so it worked. I wouldn't reccommend it though... having the compressor kick on every time you pulled a pint was annoying.