Modifying a Wine Cooler to Reach -20°C: Internship Project Help

[cthor]

Hey all,

I currently have an internship with a Nanotechnology Company. I am currently working on a cooling separator for the company's product. Nevertheless, I was doing some research and found that something already exist that I can just modify and meet my goals. I found a cooling chamber, small wine cooler cellar, that uses a peltier strip to cool the materials inside the cellar. However, it can only cool down to 8 degrees C and I want to go down to as low as -20 degrees C. I know for a fact that the strip used in the machine can cool down to -40 degrees C. My question is, how can I modify the system to obtain my desired temperature? Can I just change the control unit? I believe peltier strips uses a voltage that runs through it to control its temperature. Any help or suggestions will be greatly appreciated.

Thanks
Chong Thor

 

[cthor]

any help?

 

[Mech_Engineer]

To get the little wine cooler to much lower temperatures, you will have to get a more powerful thermoelectric cooler and a more powerful circuit to run it, or you will need to increase the insulation of the cooler. It's likely that a combination of both would be the best approach, by getting a more powerful TEC and wrapping the cooler in thick insulating material.

 

[cthor]

I asked my boss again about the constraints again and we only want to go as low as 4 degrees C. He feels like we can do it with a different controller or thermostat. When we turn the controller to its lowest, 8 degrees C, the system sounds very efficient and smooth so we know that it can go lower. Any ideas?

 

[Mech_Engineer]

I asked my boss again about the constraints again and we only want to go as low as 4 degrees C. He feels like we can do it with a different controller or thermostat. When we turn the controller to its lowest, 8 degrees C, the system sounds very efficient and smooth so we know that it can go lower. Any ideas?

Well you're right if the controller only goes down to 8C you'll need a new one.

 

[tyroman]

You might be able to use the existing thermostat and controller if you can re-locate the thermostat somewhere "outside the box". Inside the insulation blanket there will be a temp gradient between ambient and inside temp. Relocating the thermostat to the right place inside the blanket will fool the controller into thinking more cooling is needed. A separate thermostat inside the box will allow you to know if your target has been reached.