Kitty Litter to the Rescue

Well, it's summer again here in munich, and it's getting warmer. Consequently, my mind keeps turning to air conditioning ideas. It does this every year. Anyway here is the latest: An absorber cycle air-conditioner, with a water/kitty litter coolant/absorber pair. You can buy kitty litter (saw it with my own eyes on a pet store web site) that contains silica gel. It must contain a fair bit too because the page said "no clumping, only solid excrements must be removed", or the german equivalent of that anyway. Silica gel is a pretty good absorber for water so: 1: a fan 2: copper tubing 3: a valve 4: a propane burner

Get a whole bunch of kitty litter, put it outside in wide copper tubes, connect those with thin tubing to copper tubes inside, evacuate the structure (water jet pump, or heat the water until mostly steam is inside the tubes and then close a valve and let it cool), and the absorber will keep the pressure low enough that the water boils. Put a fan behind the water-carrying tubes and voila. The thin tubing connecting outside and inside has to be long enough (the part outside) to work as a condenser when regenerating (with the propane burner).