How to hook a water hose to a water timer to an A/C unit to turn water on/off when a/c goes on/off, respectively.

Requesting information on how one would go about programming a gadget such as an electronic water timer (such as a GroundWork Automatic Water Timer) hooked up to a hose and also hooked up to my Central air unit wiring outside. Specifically, I would like to have the Water Timer be "triggered" to come on when the A/C unit kicks on. I want to do an experiment which would require spraying water on a portion of my roof for temperature measurements, but I only want the hose to be spraying when the A/C unit comes on and stop spraying when the a/c shuts off. I would be greatly appreciative for any direction or guidance. Andy (rntonp@yahoo.com)

strbt6 years ago
im planning to do a project about using a PIC to control a water valve. (solenoid valve) . it should have an lcd screen to display the water timing menu . this project should be do-able.
I'm looking to do something similar; except instead of spraying the roof, I will be spraying the A/C condenser itself. Rapid evaporation will cool the charge air allowing more heat to be transfered into the medium and hopefully increase the efficiency of the unit.
NachoMahma8 years ago
. Inside the timer/valve unit, you need to find the valve actuator and verify that it works on mains voltage (110 VAC in the US). . Install a relay, with proper fusing, on the A/C circuit to supply power to the actuator. It will probably be easiest to use one leg of the 220 VAC (110 VAC) going to the compressor (or use a 220 VAC relay). You should be able to access the compressor feed inside the A/C condenser unit or at a nearby fuse/disconnect. . Unless you have some experience with electrical wiring, I suggest you do NOT mess with the A/C wiring - replacing your A/C unit is expensive. Unless you have experience with outdoor wiring, don't wire up the valve - wet wiring is dangerous.