Liquid Cooled Car Seats For Babies (or you)

Step 2 Creating the cooling coils

Since the irrigation tubing is somewhat stiff and retains memory from the coil it comes in, you'll need to attach it to something to keep it flat. The plastic canvas forms a semi-rigid base to which you'll attach the tubing. With your scissors, cut your plastic canvas sheet into two pieces and then size them accordingly for your application. For my baby car seats, I have a width of about 10 inches, and about 10 inches between where the back meets the seat, and where the shoulder straps come through the back. So that defines my cooling pad dimensions of 10"X10". But since the sheets came in 12"X18" size, my pad is sized 9"X10", leaving a 2" strip for use in some other project. I took my scissors and also rounded off the corners to minimize snagging later.

Take a Sharpie or other felt-tip pen and sketch out how you want the tubing to coil onto the sheet of plastic canvas. Keep in mind that the tightest diameter you can bend this tubing into is about 2" - and you don't want to kink it. At this point, you might want to go into your car and measure out how far from the cooler your car seat pads are going to be, allowing for enough slack to tuck your tubing away. I put the cooler in the trunk and ran the tubing out the pass-through in the backseat and to each car seat, which required about 15' of tubing per seat (3' to 5' in the seat pad, 5' for the supply tube and 5' for the return tube).

Measure out this much tubing and mark it with a piece of tape or something, then at this mark, start attaching it to the plastic canvas. Get your plastic coated twisties and, starting at one end of your inked path, attach the tubing to your plastic canvas, tucking in the twist tie ends as you go. Once you've completed attaching the cooling coil to the pad, add the same amount of extra tubing for the return section back to the cooler. I'm using all plastic parts here because if there's any condensation, we don't want there to be any rust or other damage.

Creating cloth covers: This step is optional. I did it because I wanted extra protection against condensation by providing an absorptive layer, and also to protect the inside of the car seat from damage by the twisties or plastic canvas. I bought some woven fabric from the muslin section that kind of looks like waffles. I cut it so it would be an inch larger on all sides, then had my wife sew it together into a sleeve to put the cooling pads into. She also put in three snaps. My wife is very crafty! If you can't sew, you might try the peel and stick Velcro strips.