If there’s a water pipe on the left side, right side or back of the house coming from just under the eves of the house, the pipe lets out water that has overflowed from the AC catch tray. Usually, the extra-condensed water from the AC unit runs to one of the bathrooms (sinks). But often it catches dust and eventually, it is stopped and plugged up. The water backs up and gets caught in a catch tray, letting the water flow through the pipe you see outside. When you see this, you need to go to the bathroom in which the flow sink is located and clear the clog. If the water that is dripping from the pipe is brown, it means the catch tray is rusting or has rusted, you need to get it replaced ASAP.