Step 4: The body cooler
IF YOU HAVE CIRCULATION PROBLEMS THIS IS NOT A GOOD IDEA FOR YOU! IT WORKS TOO WELL AND COULD KILL OR BADLY HURT YOU.
After my heater core Air conditioner idea failed due to the heat coming in through the window glass, I took the heater core off of the cooler and made a back heat exchanger this way:
-measure the length of the nipples on the T fittings with the tips touching,
-cut a short piece of PEX to cover that length and install it on the nipples with a PEX lock ring.
-crimp the ring in place with the pex crimper.
-continue the string of T fittings with all of the T lower legs pointing up until you reach the width of the seat back it will be installed on.
-for the last pipe you need a 90 degree fitting instead of a T fitting.
-count the number of T's and put another string together that matches the first string you made
-measure the height of the seat back and cut the small diameter PEX tubing to length
-install the PEX tubing to the T legs to connect the upper and lower runs, with the exit for the water at the top opposite the in for the water at the bottom.
-I used two 90 degree PEX fittings at the top to turn the water return 180 degrees behind the headrest of the car seat to lock it in place.
-connect the lower and upper supply/return lines to the flexible tubing coming from the cooler
-run the wires from the cigar lighter plug to the pump. an inline switch might be nice as it would save plugging and unplugging the cigar lighter every time. my cigar lighter plug has an LED in it to let me know it is getting power. The first time I used it I bumped the cord and the fuse inside the plug blew, since I knew my cell phone charger still worked that meant the plug had the open, which turned out to be the fuse.
-fill the cooler with ice and just enough water to cover the pump
-put the pump in the cooler so it is at the back in most cars, as the seat slopes toward the back.
-this design is so efficient that you could easily us a very small cooler, or do all of the seats in the car, and since the pump is rated for 500 gph it would handle all four, just install a simple in line ball valve for each seat back to regulate flow if no one is sitting there.
this set up works great and you really don't notice the pipes as the seat back lets them sink in.
-I like having clear plastic supply lines also as they let me see that water is flowing, however they are not rigid enough to keep from being collapsed by my weight against the seat back, PEX is very rigid, I could probably stand on a PEX pipe, and even if it did collapse it would just snap back.
running the water from the bottom of the seat back to the top ensures that it is always full, if it ran from the top down the water could drain through the first few tubes and leave the last few empty.