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Q & A: avoiding thermal equilibrium

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Most recent answer: 07/03/2019
Q:
I would like to ask you something about prevention of temperature equalization. I would really appreciate it if you can answer.To begin with, I want to store specific material(Thermoplastic elastomere to be exact) into a breathable microfiber bag and place it inside a safe. This material is susceptible to heat and moisture.The safe has the following dimensions: 1.2 cubic feet,interior space measures 16.81 x 12.15 x 10.51 inches L x W x H.There are pre-drilled holes for bolting which I'm going to cover in order to 'make' the container airtight.My safe is stored in a house room, where temperature does not exceed 86-96.2 F now in the summer.Given TPE's susceptibility my intention is: a)to keep lower temperature inside the bag than the rest of the room. b)to decrease humidity inside the safeFor a) I'm thinking of putting the microfiber bag inside a cooler bag that is insulated, in order to achieve lower temperature.However, I know that due to temperature equalization sooner or later it's going to be increased eventually.I don't want to cool or freeze the TPE, just to protect it as much as possible from reaching room temperature.Ice packs or freeze boards might create moisture inside the cooler bag so I doubt that is an option.For b) I also thought of adding a mini defumidifier(the one I own works best in an airtight container,that's why I previously mentioned about covering safe's pre-drilled holes) to ensure that moisture is controlled and it won't affect the TPE material.Nevertheless, a dehumidifier may increase temperature, especially now in the summer.Hence, instead of dehumidifier, I'm going to use silica gel packets inside the microfiber bag.I need to mention that I do have a hygrometer/thermometer for measuring RH and temperature.Therefore my questions are:1)If I put ice packs/freeze boards outside of the cooler bag,but directly touching it(e.g.exactly above) can I achieve lower temperature or not?2)Similar question to 1 but instead of putting icepacks/freeze boards above the cooler bag place them directly above my safe.3)Do you have any recommendation for a) and b) issues after taking into account the description of my problem?Thank you in advance.
- Kostas (age 24)
Adel,Iowa,USA
A:

The key question is how long you need to let all this sit without changing things? 

One possibility that might work (no guarantee) would be to use a Peltier electrical cooler to keep the whole safe cooler than the room. Silica gel, changed occasionally when new moist air gets in, should keep the insides dry without adding heat load..

Mike W.


(published on 07/03/2019)

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