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I'm working on a project to measure the efficiency of a mono-crystalline solar cell based on the temperature in an enclosure.

The solar cell is 150x130 mm and the enclosure will match that size and be a bit taller so I can introduce a light source.

My first plan for increasing the temperature beyond ambient temperature was to use either a heat gun or a hair dryer.

I have a thermal sensor to see the temperature inside as it increases, but I'm wondering what other options I have to control the temperature in this small enclosure more effectively.

I would like to increase the temperature to at least ~50°C, and on the other end possibly 0°C, which would likely require a different tool. I've also thought of using a small thermoelectric cooler in order to cool down the environment, as well as heat it up, but that requires a bit of setup so I'm not sure what other options I have.

TL;DR: What can I use to heat (and/or) cool a small insulated box?

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    \$\begingroup\$ Dry ice and a fan are good for cooling. \$\endgroup\$
    – stark
    Jul 14, 2018 at 4:44
  • \$\begingroup\$ or even just regular ice (with some salt if you need to go below 0C) \$\endgroup\$ Jul 14, 2018 at 11:36
  • \$\begingroup\$ I have a heatgun with precision output temperature control. These are very useful. You can get to 50C pretty easily by just blowing the heatgun into the chamber through a tight fitting hole. There needs to be an escape vent somewhere also. If the back pressure is too high, the heatgun flow rate drops to near zero. \$\endgroup\$
    – user57037
    Jul 15, 2018 at 2:37
  • \$\begingroup\$ So your question is: I have a plan to use a heat gun to heat up a box. What can I use to heat up a box? \$\endgroup\$
    – user253751
    Nov 16, 2020 at 18:11

3 Answers 3

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to measure efficiency of a mono-crystalline solar cell based off temperature in the enclosure

So, presumably you will need a constant light source to illuminate it, and maybe a light sensor to measure the amount of light. If both of these are sensitive to temperature, then you're not gonna measure the efficiency of the solar cell, rather the drift versus temperature of the light source and light sensor.

So, I would simply take a standard kitchen oven with a glass window in the front. Put the solar cell in it, facing towards the window, and tape a temperature sensor to the back of the cell with some kapton tape. Preheat to 80°C.

Put the light source outside the oven so its temperature remains constant, illuminate the solar cell through the window. Turn off the heat and measure solar cell efficiency as temperature slowly drops. You don't want any heater to be on if it generates light, like an infrared heater or a halogen lamp.

If you want to go down to 0°C then you will need to care about condensation on your solar panel and window. In this case, instead of an oven, I'd use a DIY enclosure, basically an cube made out of PIR insulation panels from the home improvement store, with a window in the front to let the light in, and a round hole in the top side just large enough to stick a flat bottom kitchen pot in. Slap a large heat sink and a fan on the bottom of the kitchen pot, and fill it with salty ice water to cool the enclosure, or with boiling water to heat it. When cooling, condensation will occur on the heat sink, and that will take the water vapor out of the air, so there shouldn't be any condensation on the solar cell or the window.

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  • \$\begingroup\$ The only major problem I see with this is that many kitchen ovens only be set to like 250F (121C) at a minimum. You could measure temperatures between room temperature and 121C in passing, but not for long periods (unless you manually manage the temperature by turning the oven on and off). \$\endgroup\$
    – user4574
    Aug 31, 2022 at 3:02
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A 100W~300W Halogen utility flood lamp is an effective heat source on a Triac dimmer to simulate Solar heat and a Muffin fan to speed up cooling response time and regulate temperature. Adjust distance to short path equal to floodlight width and reduce power before target temp as sensor may have slight delay.

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if the measurements can be made quickly you could just pre-cool it and plot temperature against efficiency as it warms up.

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