Grand Hyatt Atlanta Engineer's use Rainwater Harvesting System
Grand Hyatt Atlanta Engineer’s Observation Leads to Rainwater Harvesting System Implementation
7/5/2013 By Glenn Hasek
About a year ago, not long after starting as director of engineering at the Grand Hyatt Atlanta, Wes Shirley was overlooking the third floor terrace of the 439-room hotel during a rainstorm. He thought to himself, “What a waste. If only we could somehow harvest and reuse all that water we could really save some money.” With the assistance of a plumber, the Director of Administration and Development at Southern
Polytechnic University (who is an engineer), and some students at Southern Polytechnic University, Wes came up with a plan to harvest the rainwater that falls on the 32,000 square feet of third floor rooftop surface.
For the students at Southern Polytechnic University, it was part of a class project to help come up with a design and plan for a rainwater harvesting system. Shirley says the plan he and his team of experts came up with was quickly approved by the hotel’s owners.
Previously, rain falling down on the third floor roof went down the drain and into the city’s sewer system. Those drain lines have since been disconnected and filters have been added. Now, almost all of the rain falling on the third floor terrace is captured, stored in tanks, and reused as part of the hotel’s rainwater harvesting system. There are seven tanks ranging in size from 2,500 gallons to 5,000 gallons that store the rainwater. The tanks are located in the hotel’s garage. A 15-minute shower will produce about 4,000 gallons.
Installing Storage Tanks Not Easy
Wes says getting the storage tanks into the garage was a challenge. “We must have gone through 50 dollies getting them in there,” he says. No parking spaces were sacrificed; a storage area was cleaned up to make room for the tanks.
No electricity is consumed during the rainwater collection process. Nothing is pumped. “We do have some meters,” Wes says. “It has worked out pretty well.”
The filtered rainwater is used for the cooling tower which requires 15,000 gallons of water daily during the summer. When the rainwater is consumed, the cooling tower switches over to city water.
ROI of Less Than Four Years
If Atlanta gets its typical 50 inches of rain annually, the rainwater harvesting system should collect close to one million gallons each year. Given the cost of city water is about $.025 per gallon, Wes expects an ROI of 3.84 years.
In addition to collecting rainwater, the Grand Hyatt Atlanta harvests water from the cooling tower, recycles laundry water, and is in the process of installing a system to collect condensate from the HVAC system. The condensate would otherwise go down the drain and into the sewer. Water is also being collected for recycling from ice machines.
“Right now I am capturing 1,500 gallons of condensate a day, and 400 to 500 gallons from ice machines,” Wes says. “When we are done, it will be much more.”
Wes says he is currently investigating the possibility of greywater recycling.