An Idea for Using Solar Panels for A/C and Heat
 

Hello guys,
I was browsing around on the internet when i came across this:
http://www.thinkawesome.com/6-inch-c...ler-warmer.htm
It is a heater/cooling unit that can heat a beverage up to 149 degrees F or cool it down to as low as 35 degrees F. It runs on the 12V outlet (1.5 amps), and I believe it utilizes some kind of a heat exchanger. Upon further inquiry on this item, a smaller version of this device is available that runs on power from a desktop or a laptop's USB port. Both these power sources tell me that these devices could easily be powered by an inexpensive solar panel. Since these are built to heat water, which has a MUCH higher specific heat capacity than air, (specific heat capacity is the amount of energy required to heat one gram of a substance by 1 degree C), cooling/heating air should not be too much of a problem. Would it be possible to rig one or two of these to heat/cool the inside of a car? The heat comming out of the fan on the back would have to be redirected outside, but this could easily be accomplished. Cooling/heating the inside of the car could be accomplished by gluing a desktop CPU cooling radiator/fan assembly on the plate the beverage would sit on. By the way, I'm not trying to cool/heat my car as well as the built in climate control, but one/two of these rigged units running on solar power - combined with a windshield reflector to reflect sunlight could keep the car at a reasonable temp as it sits in the parking lot in the middle of summer. They could also be used to keep a car warm in the winter. Any thoughts on this?
Thanks

Re: An Idea for Using Solar Panels for A/C and Heat
 

They tend to use Thermoelectric coolers. One side gets hot, the other cold. Its a kind of a heat pump.

Now... with the cup holder when it cools the drink it dumps the excess heat out those vents at the back...

If you are going to "cool" a car with it... you'd have to somehow duct the heat dumping out the back to the outside of the car. Otherwise you are just moving it from the front of the device to the back of the devices (and since they aren't 100% efficient, you'd also add a bit of heat to the car.

Its sort of like taking a window airconditioner and sitting in on the bar and expecting it to cool the bar. (I've seen that done). The person doing it doesn't understand that more heat comes out the back than goes in the front.

Also... I think you are going to find out that it takes alot more energy to do what you are trying to do (even by a degree or two) than you are counting on. They make small refridgerators out of these things.. and even cooling the inside of that refridgerator takes a fair amount of wattage.

Re: An Idea for Using Solar Panels for A/C and Heat
 

A far better approach would be to simply vent the heated air via a fan.

The killer issue is the power level needed to get rid of heat being trapped by the car's glass; it's likely an order of magnitude larger current than you can generate via photovoltaic array with a car's surface area. The commonly available cells would be lucky to generate 100 watts covering the entire upper surface of the car. To keep it < 100F (in a 90F sunny location) would likely take upwards of 1000 watts using the thermoelectric blocks, which aren't all that efficient.

Re: An Idea for Using Solar Panels for A/C and Heat
 

Good to see some serious thinking on vehicle thermoelectric. I also recently saw that DOE has posted a Grant on Thermoelectric research on utilizing 'waste heat' from vehicle exhaust system. I hope this also covers the radiator cooling system; tho' not as hot as exhaust components, we hope thry can pull substantial WATTS from these
devices. With Hybrids and Plug-ins providing excellent platform for ELECTRIC power,
I am encouraged in weaning off the 'stored solar fuels' that we have been wasting in our day-to-day mentality. MF&KBY -- CDbear