Thinking about A/C, Its getting hot... Options

[Andyrew]

So... Im thinking about a portable way to make an A/C system for my v8...

But. here are the limitations.

I will not rob any hp by putting on a compressor. (more belts to possibly fail)

The unit has to be completely removable

The unit cant cost more than 150 in parts or 200 premade.


Here are a couple of options that im thinking. along with pro's/cons

ICE BOX
Build a box that holds ice packs and ice, throw some fans, some switches, ect, and get some ice cold air coming at me.

Pro's. Cheap, 20 bucks in airplane fans, metal/wood is cheep, Plastic sealing, Mesh for the ice to sit on, switches, and an lighter plug..

Cons. Sealing it will be a problem, Drain off might cause some issues, Ice will only last an hour max, ice packs will be maybe 2 hours cold.


PREMADE

Couple of company's are out there making beverage coolers and warmers..


http://www.amazon.com/gp/product/B00005R2M...&n=15684181
http://www.globalsources.com/manufacturers/Car-Cooler.html

Even

http://www.kooleraire.com/index.htm

Pro's.. No fab...

Cons.. Not for cooling the car, but food


Thermoelectric...

Now it gets interesting... I read some stuff, and noticed most of the coolers are using this thermo electric thing... Now how can I make this into something useful?

If I understand it right, one polarity heats up one plate, and one polarity freezes another plate.

So..

http://cgi.ebay.com/Thermoelectric-Peltier...1QQcmdZViewItem


http://cgi.ebay.com/Gigantic-62mm-350-Watt...1QQcmdZViewItem


If I used them instead of ice... I might get some pretty darn good cooling output?!?
But what about power usage?

Those little things I just dont understand... Anyone want to help me and tell me if im dreaming?

Thanks

Andrew

[Andyrew]

Michael, I understand that it will take some hp to make it cool... But as long as that hp is regainable (unplugging it is simple.. lol)



Mike, I saw the swamp coolers, and it seemed like a good idea! Yet, when the 914 gets moving and their is wind in your hair, the sweat from your skin does its own evaporative cooling.. The problem is, when your in stop and go traffic, and the cabin gets 120 degrees...


Mark, An intercooler, air passes through the intercooler, ice surrounding the intercooler, Maybe even some peleter things with the cold side to the cooler...Throw in some fans to move the air at the driver and passanger...


Johannes, I think im going to stay away from evaproative cooling, because I rather wouldnt want to throw water on my head while im driving to stay cool.....


My thought now is to do a mixture of Peleter things and ice... The reason for the peleter coolers would be to keep the ice cool for a longer period of time and to lower the temp of the air coming out.


Is it possible for these peleter coolers to be run off of solar pannels? Leave the pannel on the dash or in the sun while the car is sitting to keep the interior of the car at a decent temperature...


What do you guys think of those ideas?

[MBowman325]

Mark, An intercooler, air passes through the intercooler, ice surrounding the intercooler, Maybe even some peleter things with the cold side to the cooler...Throw in some fans to move the air at the driver and passanger...


My thought now is to do a mixture of Peleter things and ice... The reason for the peleter coolers would be to keep the ice cool for a longer period of time and to lower the temp of the air coming out.


Is it possible for these peleter coolers to be run off of solar pannels? Leave the pannel on the dash or in the sun while the car is sitting to keep the interior of the car at a decent temperature...

I think that with peltier junction, you may not realize that there are two sides, and it's not just one temp on both, but hot on one and cold on the other. If you have an efficient way to cool (an evap core or some other type of item willies with fluid) that you can bond to the cold side, AND you have a good way to dissapate the heat the hot side generates, then that's half of it.

For grins, I went looking. A 40mm sq peltier costs 12.75 ea from All Electronics (sorta surprised Digi-Key didn't list them..) The specs it shows are:

127 thermocouples per device
deltaTmax=79degC (or 174 dF)
Thot=50degC (or 122 dF)
Vmax=16.1V
Qmax=56Watts
Imax=5.6A
40MM x 40MM x 3.8MM

Assuming that the temps are listed as maxes for both, and seeing that the max current at 12 volts is over 56W, you won't see that sorta output. (Which is impressive I though BTW.) Assuming a linear scale, 12v, 4.6 A (56W), we could see a deltaT of (at least?) 59dC. Someone would have to clarify for me if this is Delta Ambient or Delta Hot. Assuming Delta Hot at a 25% reduction, then that will give damn cold temps (-21 dC), so I've screwed up somewhere. (IMG:style_emoticons/default/confused24.gif) My Physics teacher didn't like me in HS, and that was about eight years ago... (I could also need to be figuring more on a reduction in the current, at 17% instead of voltage for this application, but my direction is not correct either way)

Anyways, the cold side looks appealing (Max outputs are typically not reached in real world situations as well), but you still have to figure out what to do with that (up to) 122 dF it's pumping out from the hot side. If you don't carry a passenger, and don't mind ugly, it'd be easy to vent the hot out the pass window. At any rate, you don't want it dumping back and mingling with your cold air.

..

Looking around, an informative article (relating to use on processors) is at http://www.heatsink-guide.com/peltier.htm . You can translate heat to Watts and it may provide a rough idea on what is possible. I should be asleep already so I'll not dig out some notes I found a couple of weeks ago on that.

All I've said, I've never ment to imply that you shouldn't try, I just wanted to make sure that you're aware that it always does hot and cold at the same time. (Yeah, sorry, it took a lot of lines to spit that out) And find a good way that doesn't tax the electrical system on the 914. (A pump, plus a couple of peltiers for an air/fluid/air system would start to add up on Amps I'd think). If those two can be addressed "cheaply" then you're well on the way to being able to build something for well under $150.

(Heater core / used evap core, some plumbing, a couple of peltiers, related heatsinks and fans, fluid pump and a blower. A butchered small ice chest before or after the air flow through the core that allowed air to flow through a block of ice would be of benefit for a little bit. A felt covered bracket and hang the peltiers on the roll bar or off the other side of the door.)

(IMG:style_emoticons/default/unsure.gif)

OK, I'm going to bed now. Sorry for the long post...