7 replies to this topic

[scootertig]

Like everyone else, it seems, I got an idea for using Peltier devices to improve my brewing process. Instead of cooling my fermentor, though, I was wondering about using it to improve/speed my wort chiller. I haven't figured out exactly how it would work yet, but I'm thinking I could either use it to chill the wort after it leaves my Shirron plate chiller, or use it to chill the water going into the plate chiller. My gut suggests that the wort option would be more effective, but it may be an even swap.Has anyone a) seen or b) tried anything like this? It seems that for the relatively short period of time I'd need it to run, that I could keep the peltier device cold enough to really drop the wort temperature quickly, but since I haven't seen this mentioned, I'd guess that I'm missing the fatal flaw in the idea.Thoughts?aaron

[3rd party JKor]

The issue is going to be contact area. Even if you're maintaining the cold side of the peltier near 32°F, you're not going to change the temperature of the wort much if it's only in contact with 1-2" of the cold surface.Ideally, you would figure out how much cooling load your peltier can handle, then design a heat exhange system that has enough area to fully utilize the peltier's capacity. Not exactly a simple task.Trial and error is a viable system design method , as well.

[BrewerGeorge]

Peltier's can't absorb a lot of heat quickly. They're even worse than conventional, compressor refrigerators in this regard. They're good for keeping things cold, but not much good for getting them cold in the first place.

[HVB]

So would you not recomend them for cooling a conical? Sorry for the thread jack ..

[BrewerGeorge]

So would you not recomend them for cooling a conical? Sorry for the thread jack ..

I've seen pics of people using them for that. That's relatively easy, though, because the Peltier's only have to be able to absorb the heat of fermentation and the surrounding air. The amount of heat required to take wort from 210F to 65F is drastically bigger.

[scootertig]

I've seen pics of people using them for that. That's relatively easy, though, because the Peltier's only have to be able to absorb the heat of fermentation and the surrounding air. The amount of heat required to take wort from 210F to 65F is drastically bigger.

That's why I was thinking that I'd do it post-shirron. I can reasonably expect my ground water to get me to 70-75-ish during the summer, but getting any lower is a trick. I thought maybe it would let me get wort to 60-65, where I can pitch (for ales anyway) without having to wait...You think it's still asking a bit much?aaron

[3rd party JKor]

I've seen pics of people using them for that. That's relatively easy, though, because the Peltier's only have to be able to absorb the heat of fermentation and the surrounding air. The amount of heat required to take wort from 210F to 65F is drastically bigger.

Right, fermentation happens on a 'days' timescale, wort chilling happens on a 'minutes' timescale. Just as a reality check, if you were to cool 5 gallons of wort down from 95°C to 90°C that represents an enthalpy change of about 383 kJ (using the physical properties of water). If you wanted to do this over the course of 10 minutes (600 seconds), the power requirement is:P = 383,000 joules/600 sec = 638 wattsThe peltier elements I've seen aren't anywhere near 650W (although they exist). So you'd need a train of peltier just to chill the wort down a few degrees coming out of the kettle. I don't think it's an effective use of a peltier.One thing to think about is using an old window AC. Pipe the output of the AC directly over some copper coil, with heat fins if you can get it. That would probably be a pretty effective pre-chiller. Plus it's a lot less design work, and probably a lot less cost.I've actually started building a peltier-based fermentation chiller. I think it's doable, just not the most effective thing in the world. I'm doing it more for fun. I've had the materials for it for years. Based on where that project is on my priority list, I'm not sure I'll ever finish it.

Edited by JKoravos, 13 May 2009 - 12:07 PM.

[pods8]

That's why I was thinking that I'd do it post-shirron. I can reasonably expect my ground water to get me to 70-75-ish during the summer, but getting any lower is a trick. I thought maybe it would let me get wort to 60-65, where I can pitch (for ales anyway) without having to wait...You think it's still asking a bit much?aaron

Yes I think its a bit off. I'd either be looking at using iced cooling water or chill it to what you can then get a fermentation fridge/freezer to chill it the rest of the way and then pitch.