Thread: Battling summertime heat issues . . .

kirk78h, if your comp dies at 80F (26C) maybe there something wrong with the components... 26C is regular temp for comps. I actually have 26C in my room rightnow. So check components and see what exactly causing the failure. You siuld not see problems at least untill temp heat 32-40C

My touch screen is pretty much in direct sunlight at times in parking lots and while the screen hasn't failed, the case of the screen has warped a little. It hasn't effected operation as of yet, but it makes me want to get some kind of silver reflective cover for it maybe when I know it'll be in the sun for a while parked.

As for cooling options, the peltier idea has been mentioned over and over through the years and I think I'm about to attempt a peltier solution. Most people go directly to one of two things when it comes to peltiers: condensation or the excess heat from the hot side of the thing. I think it can be managed though if the point is to simply make sure something like a trunk is in an operating range. The purpose isn't to get the computer or the environment down to 'cold' temperatures, but simply to bring the environment down under that 100F / 38C threshold that seems to be a breaking point sometimes.

My idea would be to install a peltier under the spare tire with the hot side of the device exposed to the outside air. Then have a fan blowing across the cold side into the trunk.

The air coming off the peltier may be super cold, but by the time it mixes with the trunk air when it's over 100F/38C I can't see the trunk getting much cooler than 80F/27C.

With that kind of a setup you would have a small footprint for the cooler, it would be out of the way, and I can't see any condensation issues since there's no way a small peltier could get an entire trunk down to a dew point. But it should be able to get the environment just that little bit cooler that the components like.

Comments?

You will HAVE to post details on how this works out!

I've been shopping for a peltier to use and I think I'm going to gut a portable 12v cooler to make my solution. They advertise being able to drop that small space down 40 degrees under ambient (so down to 70 degrees from 100). I think that should be perfectly sufficient for a car trunk. I'm thinking that I'll make a square duct from the bottom center of the tire well where the peltier will live to the back of the trunk (towards the rear of the car) for input air. Then I'll have a fan vertical in front of the peltier blowing across it to a square duct that exits towards the front of the car.

I wonder if I should mount a heatsink to the cold side to blow through? That makes sense right? (anyone who's worked with peltiers know the answer to that?) If it works for heat it'll work for cold too since it's the same principle I think.

I did a quick mockup just in case anyone didn't follow what I meant. Obviously the scale is way off, but this is the idea.

The target temperature for the trunk would be 80F / 27C when it's 100F / 38C outside.

http://www.dvigroup.net/share/pictur..._diagram_1.jpg

This also has the side benefit of cooling my car stereo amp. I don't thermal it very often, but on very hot days while I'm on a road trip and thumping pretty hard down the highway it's been known to happen. I usually just drop the back seat down to help my air get to it from the front in those cases.

I'm interested to see what the final solution you use for ambient cooling. I have been brainstorming a solution for this for a while for use with in-car solar power.

See my post regarding using solar energy in the car. I am still brainstorming this and my second main issue how to relieve some of the heat in my car while it is idle. I live in climates that can reach up to 120F in the summer. Imagine how hot that it ends up being inside the car. http://www.mp3car.com/vbulletin/how-...ur-laptop.html

So yes, I am curious to see what your cooling solution will end up being.

....I just wanted to add on other thing..it's funny someone in this post mentioned the idea of gutting a 12v portable cooler...LOL! I was investigating that idea also.

My question is how much power (electricity) does it take to drop the temp by 30 degrees? Would it overload the battery between an amp, pc, and a cooler for the trunk? I'm sure the little fan wouldn't take up all that much, but I know heating stuff takes a lot of juice so I imagine doing the opposite would require a fair amount too.

why don't you go in the offensive instead of the defensive and tint your windows, my car dropped 10 -15 degrees since i got my windows tinted.

PS: don't cheap out on the film buy the good stuff, it'll work better and it won't fade or peel off, i got Formula1

My windows are tinted now, and the environment outside ranges from 90-110 outside usually but can climb a little higher. My stuff is in the trunk, out of the sun completely so the tint didn't change the trunk temp of 90-100 after being in a parking lot for several hours.

No matter how dark it is in the trunk, it's still a metal box sitting in the sun. So eventually it will at least match the ambiant air outside. With insulation you might be able to keep it 5-10 degrees lower, but that may not be enough.

People reference the trunk being MUCH cooler than the car, and that's usually true since on a 100 degree day the inside of the car can get to 140 or 150 easy with the right conditions. The trunk will still be close to 100 though and that's too hot for a lot of the components to be running at.

My biggest problem right now is actually my startup/shutdown controller. The PC itself has never had a glitch even up to 120 degrees. The cpu and hard drive are kicking just fine, but that startup/shutdown controller starts fritzing out at 100 or so. It may not be GOOD for the PC to run that hot, but it will run none the less. The startup/shutdown controller isn't as tollerant.

Which is how *I* got to this peltier idea. The cooling should allow the startup/shutdown controller to function, and as a bonus the PC will be much happier.

I'm sure the current draw for the peltier is pretty high, but part of MY plan anyway is to put in a second battery with an isolator (seperate from the heat issue, I have a voltage drop issue now since the PC is right off the car power since I'm using a simple startup/shutdown controller instead of a DC power supply). The peltier would be powered off the second battery along with the PC while my stereo amp would remain on the normal power.

If the second battery dies, that's fine. But I bet I could come up with something that delays the starting of the peltier until I unlock my doors. And that same delay component might delay the startup/shutdown controller as well. Just to give the peltier a minute or two to start pushing some cool air around.