mysobry

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Hi
I have moved the discussion in a specific thread form the thread dedicated to fermentation chamber peltier cooled since the two project, a part from cooling technology, have different solutions and development.

The idea is to use an immersion water chiller inside the conical fermenter and recirculate cold water. The cooling is provided by a peltier air-water heat exchanger using a technology for PC watercooling (overclocking CPU)

I have sourced a surplus COOLIT freezone…that was made by a Canadian company. I got it from a surplus ebay auction



The basic principle is very simple the cool water is recirculated inside the conical fermenter via a stainless steal coil and is cooled by the peltier cells.



The coolIT exchanger is a very nice piece of engineering…very compact, colplete with pump, peltier cells, reservoir, fan…and it comes with a controller board that can control the power applied to the 6 cells and the speed of fun/pump according to set point and current measured temperature. So I expect that once the worth has reached the target temp the power will be adjusted in order to compensate just the heat produced by fermentation and loss of the system





The unit can be controlled by software PC via USB but it can works also stand alone…it is possible also to log temperature and power during the whole time !

The stainless steel coil has a diameter of 20cm and an height of 30cm. The pipe is 8mm OD , 7mm ID. The terminal are 90degree bended in order to exit the side wall of the fermenter so all the coupling and fittings are external (safer !). Two compression fittings keeps the coil in the canter of the fermenter



In order to avoid dispersion I have insulated the fermenter (both the side wall and the cone) using a foil of polistirolo and some neoprene.



Than after some trial I have substituted the original small 12V pump with a bigger one capable of 500l/h. The pump is a Thermaltake P500 pump and the fittings again comes from the PC modding / watercooling thecnology. It’s very low noise with ceramic bearings for long term usage. It’s compatible with high flow systems utilizing ID 6.4mm(1/4”) and 9.5mm(3/8”) tubing.



Last addition is a water reservoir..it’s very usefull when you fill the circuit and for eliminating bubble in the flow. It’s very compact and transparent so you can se water flowing. It has 4 1/4’’ port one used for the inlet, one for the outlet , one for temperature sensor and the top one for refilling.



I have also added a small water temperature monitor with a sensor inside the reservoir. It is not connected to the control board that has it’s own sensor but is just to monitor the temp without connecting to the PC via USB. The small circuit in front of the thermometer is a DC-DC step down converter in order to have 5V supply form 12V main power supply.





Here is the complete assembly. Up to now I have tested the fan, the controller and the water recirculation and it works fine…very compact , low noise, easy to mange. In order to complete the test I need to connect a proper power supply (12V -150-200W0 and I’m waiting for the delivery)

next post hopefully some results and experimental data
enjoy
Davide

microbusbrewery

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That's a pretty sweet setup! It's definitely more compact than a traditional fermentation chamber.

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wyzazz

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Nice, it will be interesting to see how it performs. Thanks for the write up!

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mysobry

Recipes 

At the end of the day after few tunings and mechanical/hydraulic optimization I succeed in testing the system.

Saturday I have brewed 30L of ESB and I had the chance to cool it in the new fermenter.

the video below show you details of the rig (as soon I have time I try to insert some label in English)


As far as performance concern it seem to work fine.. the temperature was dropped from 21C to 19.5C (my set point) in less than an hour...than the temperature was stable and the power applied to the pletier cells at the minimum (40%).

One point that I have to verify is that the controller software doesn't allow me to set minimum power=0 the lower value accepted is 40%...this could be an issue if the room temperature is not so hot the 40%of power continuously applied even if you reach the set point could lead temperature too low..
I have to verify this point when fermentation starts to produce heat..menwhile I try to contact the manufacturer in order to see if there is any chance to set lower limit =0

The system generally speaking is very compact, easy to manage, and …hi tech !

I will let you know further progress
Stay tuned
Davide

mysobry

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Some more picture with the final set up...all components have been have been tighten on the base and some neoprene foil have been inserted in order to reduce noise and thermal transfer








do you like it ?

Davide

Pilgarlic

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This is a gag, right?

ChandlerBang

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Very nice. What is the maximum theoretical BTU/hr rating on that?

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mysobry

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Sorry I don't catch the question...maybe is my not so good english...but the project and the implementation is very serious and....it works !

wyzazz

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This is very cool, once you've given it a good run through you should submit it to BYO Magazine.

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mysobry

Recipes 

Thank you for the compliment…I term of performance I have not calculated a sophisticated thermodynamic model…my approach was more empirc based on what I’m able to source on the surplus market at a reasonable price. Nevertheless some figures are available and I’m pleased to share..maybe you can help me in a math model.

I’m not familiar with US/GB unit measurement so everything is expressed in wat, Celsius etc..



The core of the unit are 6 peltier cells that are rated 72W maximum power..this is the absorption…I discovered that are under powered in order to work in a safer condition. Some PC modding project overpowered the cells or substituted with more powerful one.



According to this graph the unit is capable to dissipate around 120W with 0 delta to ambient temperature…so assuming that 30L of fermenting wort produce 100W heat you can cool at room temperature…If you want to go below room temperature you can dissipate 50W with 10C delta..

From my experimental test I was able to cool the fluid with no “load” (empty fermenter) up to 10-11 Celsius with 22C ambient.

One point that I’m still investigating is that the minimum power unit that you can configure via control software is 40%...even if the temp reach the set point the control unit still apply a minimum power of 40%...that is not so low..infact with water experiment I had a temperature slowing decreasing. In case of fermentation I’m still verifying if the heat produced by the fermentation compensate the 40% minimum power…I’m also investigating with the manufacturer if I can configure the minimum = 0



Last graph is related to thermal resistance according to power @100W it’s 0.1W/C that if I understand the number is quite low compared other cooling system (air-air)

Hope this data are useful..maybe we can start a more analytic thread for dimensioning peltier cells in such an application

Davide