Starting My A/C Seat project
 

I'm doing this in response to http://ecomodder.com/forum/showthrea...html#post45024

Plan
Basically the plan is to remove the covers from my factory 06 Jetta leather seats (already had to do once to fix heater) then glue tubing (thinking headliner adhesive) to the inside of the seat leather (already canvas backed). Then fill in the "gaps" between the tubing with foam rubber of similar thickness/ firmness to the silicone tubing.

System Componets

Heat transfer Tubing I have purchased Elite Silicone Airline Tubing By Hagen - Air Pumps & Accessories - PetSmart is very soft, rather resistant to kinking, is very thin and is not very unreasonably priced.


Filler Foam Rubber
I went to a fabric store looking for foam rubber to fill in the gaps; but no luck so far. There is an upholstery shop that I can ride my bike to; I think I'll hit them up when I get home.

Water Distribution Manifolds
I'm planning on putting manifolds in the crease between the seat and the seat back, this will allow for fairly even flow through each of the 8 planned loops (4 loops (out from center then back to center) on seat and 4 on the seat back). So I'll need 16 "T's". I'd like the manifolds to be of a larger size (say 1/2") So I'll need to locate the T's and tubing to match design. I figure if I seal all of the T's Up with marine Adhesive there is near 0 Chance of Leaks . -> Highly recommended West Marine: Fast Cure 5200 Polyurethane Adhesive/Sealant Product Display

Pump Thinking of starting out with a used windshield washer pump however they are loud and I am unsure about their duty cycle. I was thinking about PC liquid cooling pumps, but they are rather pricey. Any other ideas?

Cooling
I'll probably start with a little ice chest with cold water in it; but want to upgrade to Peltier cooling so I don't have to carry ice out to the car, or take up much room. Something along the lines of a heat sink on the Hot side of a peltier and a water block on the Cold side of the same peltier. The Hot side could be mounted inside the HVAC system; as long as you always had air flowing through it you wouldn't have to have an additional fan and that way you could super cool the system by running the A/C compressor for a few minutes.

Thermostat
Probably the last thing on the list. I want to make the contols as factory as possable so here is the plan.
1) Install heat/ cool switch for the factory seat heater control.
2) either a) get a temp sensor which is inverse of the factory "Heat" sensor or design circuit to reverse the output (I know ambitious). (switches with the Heat/ Cool switch)
3) have the factory thermostat wheel mounted in dash control the coolant pump whenever switched to "cool"



Comments, suggestions ETC Highly welcome

I had posted a response here outlining a commercial available racer's 'kool vest' a while ago, maybe you read it.

For the heat side, I don't know about having engine coolant flowing through my seats... too many chances for a real mess IMO. How about a liquid-to-liquid heat exchanger where the engine coolant doesn't actually flow through the seat tubing... wait, if it's straight water, it freezes during a cold winter night. Hmmm...

For a cooling pump and ice buckt, look at small live well <fishing> bait recirc pumps. Maybe Bass Pro Shops on-line sells a self-contained 12v units for anglers with little aluminum boats?

I have used Kool Long sleve shirts and cool helmets, that's where the Idea "seed" came from. Re-freshed by various mentions on this forum.

I already have electrically heated seats, sure waste heat would be more efficiant, but I'd rather just leave well enough be.
If you want to see a terribly bad Idea, look at the early versions of the New body style 7 series BMW. The seats are heated by engine oil (electrically boosted)! Nearly every one leaked and had to be replaced under warranty (along with carpet).

I honestly hadn't thought about the coolant freezing, I guess I can add just a tad of antifreeze when winter comes around, should have found any leaks by then.

Good Idea. Rule Livewell Pumps Only issue I'm foreseeing is that they appear to be modified bilge pumps which in my experience are very low pressure, but high flow. Hopefully not because that would be ideal.

Pump ideas
FluidXP+ Magnum PC Water Pump (3/8in) Price falls in to acceptable for project, but lack of info is not helping

And the 1046 sounds good as well. Water Currents and Movement in Aquariums: Eheim Hobby Pumps


Maybe I need to increase the number of loops so as to decrease the required pump psi . . .

I have been thinking about just such a project - every time the A/C compressor kicks in
Wish you the best

have you considered just slitting the seat foam and pressing in the tube
it seems like it might be thin enough to work and you would not have to worry about destroying the contour of the seat.

or would this lead to seat heater issues?

I have NOT, but I am now.

I would have to cut the cushion, not the seat cover (seat cover is thin).

I am guessing that the slit depth would be critical with the required mounting system; maybe a V? Might need a cutting rig of sorts . . .

How about if I used something like aluminum foil (but quiet?) glued to the tubes + the seat cushion to act as a heat spreader? IDEAS?


Had I thought of that earlier I wouldn't have spent so much energy looking for just the right tube LOL

FYI, hadn't seen any commercial products mentioned yet, heres one @ $119:
Cool-or-Heat - Features and Uses

I don't know any more about it than that, guessing peltier, so you could add an alternator to the driveline for regenerative cooling? :)

Edit: I did see in http://www.coolorheat.com/warranty.pdf
It is 3 amps @ 12 volts, cools to 40 degrees below ambient.

Regenerative cooling LOL.

I have seen those, but like I said someplace else I strive to keep my car "nice enough to drive even if gas is $1.00 a Gallon" and I'm not in to covers. Now if I was just slightly less picky I'd get a pair of those and a pair of seat covers.

I already tax my electrical system pretty heavily; a few more amps will fall right in to the tank to tank noise. And that Load will be MORE than offset by running the A/C compressor that much less/ harder.

coolorheat review & proto type ideas
 

$119 is high for an experiment
but if it saved me 2 mph on the truck that would pay back in one summer
has any one see this in a store - I would like to see how fast it cools

Wait... never mind
View All Reviews
- so much for a Peltier solution - I hate that - reality stinks sometimes

Back to the task at hand

Dremd
you could use screen or copper braid - quieter than foil
the problem is metal could abrade your seat foam, leather and tubing

The seat foam should insulate the tubes well, so you should just be cooling your butt. Maybe your first try could be just the slits & tubes.
especially if you are using ice water (Brrr)
it might not even need glue (at least short term), then you would be free to rework or redesign without permanently destroying anything, for now.

Maybe this pump?
 

Water fountain pumps are inexpensive and usually quiet. Hopefully your car won't turn into a babbling brook. This sounds like a reasonably great idea, I like it and would do it myself.

https://www.hardwareworld.com/Founta...p-pN7NS7D.aspx