A new cistern has been created that uses the condensation from air conditioning units to flush toilets, and its inventors say it could save 4.7 billion liters of water at more than 1,477 U.S. hotels.
This water would have originally gone to waste, says David Davis, Encore Technical Director, but “We’ve developed the only cistern that uses this free water to flush the toilet.”
Most air conditioning units have a pipe that drains away all the condensation that forms as the unit runs. If one were to combine all the AC units in U.S. businesses, that condensation would amount to billions of gallons of water.
If the system could be applied to the home, even more water could be saved. When one considers that just a small home leak can lead to a loss of 90 gallons or more daily, it’s clear that even small drips of water can add up quickly.
“All buildings need toilets so why wouldn’t you use a cistern that recycles a free, sustainable water source especially when there is a global water shortage crisis?” asks Davis.
The system works by holding 18-liters of water total, which is three times the conventional storage of an average cistern. It has dual chambers, meaning it can fit most standard designs. The bottom is a 6-liter storage tank, and the top holds the remaining 12-liters. The bottom chamber has a lead from the main pipeline, while the top is filled with the air conditioning condensation.
When the toilet is flushed, the bottom empties and fills with water from the top, and if multiple flushes are made quickly, or the AC is not used often, the cistern fills from the main water pipe as normal.
It also feeds away the excess water generated if there is no flushing over a period of time.
The figures for 1,477 hotels is based on data from a STR Global study that shows there are an estimated 191,832 rooms and 1,477 hotels being built in the U.S. right now. Installation of the Encore-enabled toilets would, according to the company, save the equivalent of 1,880 Olympic-sized swimming pools.
The AC condensation-using system would also allow architects to secure two extra LEED points, which are the U.S. Green Building Council’s gauge for sustainability when constructing buildings, says Davis.
“Responsible businesses striving to construct the greenest buildings know how hard to get LEED points are,” he adds.
Air conditioner manufacturing is a thriving business in many parts of the nation, especially with the opening of a massive 4.2 million-square-foot factory near Houston, TX this year. This means that there would be plenty of condensation to use for these Encore units, though HVAC technicians would have to be trained on making these systems integrate with Encore.
Fortunately, there’s no shortage of HVAC pros. The average HVAC technicians earns a $48,000 a year salary, and the industry has been growing steadily for some time now. By some estimates, the industry will increase another 16% in the coming years.