posted 12 years ago
A clothes washing machine is the easiest to capture in an existing house, rental or not. The machine has a pump for the water discharge, which means you can have an outlet for it at window height. I would run a 1.5 inch PVC pipe out the window and to the tree/ location you want grey watered. You can even have several pipes out the window for different locations, just move the washer discharge to whichever one.
For anything other then a washing machine it will be harder, as the pipes are covered in the walls. I suppose you could remove the p-trap under a sink and rig up a garden hose fitting and run that outside, but you have to make sure you maintain a downward slope, and be careful that nothing but water goes down so it doesn't clog the small line. Also, if you disconnect the p-trap, make sure you properly (temporarily) cap the drain that continues into the wall, so you don't get sewer gas into the house.