There's gotta be a better way

[hondaworkshop]

Circulating air or water past an external peltier then into the cabin or chair could eliminate the problem of ambient heat from its back-side.

[jdub]

Originally Posted by Bicycle Bob

The trouble with using Peltier junctions in the seat is that the heat has nowhere to go, and now there is more of it. If you are going to have to ventilate the seat anyway, natural evaporative cooling may be sufficient. If not, there are more efficient ways to pre-cool the air by a factor of four or so.
I'll be investigating the efficiency of just compressing air and cooling it back to ambient, or perhaps adding evaporative cooling, and then expanding it again to provide a flow of cold air. Just using a 12v tire inflator would probably not be very efficient, but it might concentrate the cooling effect enough to make up for that, and offer a savings over whole-car cooling.

Its a heat pump just like on a house, so you put one side on the outside of the car (connected to a heatsink for example, or just to the floorpan under the carpet and the jute padding), the other in the seat!

Problem solved.

[jdub]

Application - Amerigon

The names of some OEMs who are using them:

DRIVING: BELLS & WHISTLES; The Hot Seat (Or the Cool) - New York Times

Potentially some junkyard opportunties here, although understanding how the system is configured and where/how its set up to move the heat/cool to/from would be reqiured to make sure you get all the necessary parts to the system from the donor car.

[jdub]

Cool-or-Heat - Features and Uses

Datasheet
http://www.coolorheat.com/datasheet-sc.pdf

It looks like it uses a peltier to cool water that circulates through the cushion itself. Looks like it goes for $120.

Still trying to track down the version that you can retrofit under existing or new upholstry... Will post when/if I find it.

[Tango Charlie]

You guys with sunroofs could put these peltier things in a panel that replaces the glass panel. Put the hot side up and the cool side down. Imagine a cool draft over your sweating brow... ahhh.

[jamesqf]

Originally Posted by jdub

Thermoelectric couplers (or peltiers as they are sometimes called) use the Peltier Effect to heat pump (by consuming a small amount of electricity) temperature from one place to another.

One mistake in that, which makes the concept unworkable. The Peltier junction uses a LARGE amount of electricity relative to the amount of cooling produced. The standard car A/C would use much less power - and you could run some plumbing to duct cool air to the seats.

[jdub]

Originally Posted by jamesqf

One mistake in that, which makes the concept unworkable. The Peltier junction uses a LARGE amount of electricity relative to the amount of cooling produced. The standard car A/C would use much less power - and you could run some plumbing to duct cool air to the seats.

This post, referencing what looks like the exact same seat cover shows that this seat cooler only uses 30W of power. It runs off 12VDC and draws under 3 amps.

[EVDRVR]

Worthwhile reading.
Thermoelectric cooling - Wikipedia, the free encyclopedia

[extragoode]

First, I like the absorption cooler, but thought that they had the same problems as Stirlings in that they were bigger heavier and more complicated than was possible to implement in a car.

Second, there's a lot of talk about using different cooling methods that would be impractical at the same power level as the current system, but downsizing them to only cool the seat/person. Why not keep the same cooling method (since it's fairly efficient and you're using mechanical energy where it's being generated, it's just the ICE that's inefficient.) and just downsize and modify IT to only cool the seat/person? The AC wouldn't be hurting your FE so much if it were 1/10 the size and power. All the current AC systems are overpowered to cool the entire cabin and FAST. Every AC unit I've used I HAD to cycle because it's TOO COLD even on low. I know this doesn't fit all the criteria, but it seems like the most straight forward solution to me.

Third, I know just cooling the seat would not be enough for my wife if it is sunny!

[dutchboy]

I read about some people insulating the low pressure A/C pipes with "high heat" pipe insulation from the hardware store. They say it makes the air just a bit cooler.

I am planning to do this. I figure making the ac system more efficient will have some effect on FE.

I have also heard of people bypassing the heater core during the summer, with some small improvements.

Getting the heat out of the engine bay might help as well (wrapping the headers, etc.)


What about turning the ac on, then putting it on re-circ and turning the AC off? I have done this before, and the cold lasts for about 5 minutes or so...Is there a downside to this?