This machine is a perfect first project to get your feet wet with phase change systems. There are plenty of orphan window a/c units in the perfect size range just begging to be adopted. I am waiting for a reply on craigslist as we speak on a 12000 btu window shaker for $25. For that price, I don't really care what's wrong with it, as parts are worth more than that in scrap value.
What I plan on doing with one of these units is simple. It works incredibly well with dehumidifiers also. I will be making a condenser coil like Randen did. The technical term is a helical element. The element is brazed into a standard heating element bung, and screwed into the water heater before being plumbed into the window shaker. The helical element replaces the bottom electric element in the water heater, and the condenser coil in the window shaker.
The window shaker condenser will be plumbed into the suction side of the circuit, rather than being removed. The additional airflow and hx surface area should boost performance by a substantial amount, especially at lower water tank temperatures. Also, the unit would not tend to freeze its evaporator coil at temperatures above 35-40 degF.
The only mystery I have not solved yet is how to exercise control of the unit. At first, I believe I will just leave the most basic setup, and see how everything works. If I think I can get more out of the unit, I may end up replacing the stock cap tube with a TXV. If the stock water heater thermostat control makes the compressor short cycle, I will add a time delay lockout or more complex temp control to solve as yet unseen issues that may arise.
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