Rain barrel fed by AC drain

I have a rooftop garden in downtown Tampa and thanks to the lack of an outside spigot have to manually transport water from inside. Well had to, now there’s a rain barrel that is fed by the AC unit. Being in humid Florida and for cooling a couple thousand square feet, the unit puts out a lot of water per day (at least five gallons) and was previously emptying onto the roof and simply going down the drain.

I searched Amazon for a rain barrel and got a model from Algreen. After it was delivered I went to Home Depot and bought 3/8″ tubing and a 3/8″ hose barb splicer to connect the existing tubing and my extension. The rain barrel I bought (like almost all) is meant to tap into a gutter system, but has spaces to drill holes for tubing to connect multiple barrels together and/or for diversion when the barrel is full. I drilled a 3/8″ hole in one of these and inserted the extended AC drain tube and drilled out the other to divert into the drain. The photo is after the first portion, the hose shown is coming from the AC that is on the building’s roof. The building has 10′ ceilings and about a 4′ crawl space above that, but there’s a half height portion where the door out to the deck is and that’s what the barrel is on. It’s convenient in that the water is coming from basically a story above the barrel and the barrel is feeding a garden about a story below–gravity is easy to harness.

It almost immediately started to fill with water and so far is providing more water than I need for the garden (time to get new plants!). It has not filled completely yet so I haven’t had time to perfect the overflow. For now it’s just a hose out and into a drain.

This is a great way to use a rain barrel for when you don’t have a gutter system in place or don’t want to use water that has been exposed to your roof. For the most part we have a flat commercial roof without gutters, not to mention all the tar and associated materials that roofs contain. This clean water was previously being thrown away. I’ll have to figure something out in the winter when the AC is not running, but for now it has the added benefit that it generates the most water on the hottest days which is exactly when the garden needs the most water. It’s a simple hack and took remarkably little time. The barrel itself even shipped overnight with Amazon Prime so the most time consuming process was probably hunting around Home Depot.