The Grand Hyatt Atlanta, a local plumbing company and a local university have formed a unique partnership which has changed the footprint of how the hotel uses the over stretched fresh water resources in Atlanta, according to Wes Shirley, director of engineering at the hotel.
In Atlanta, the hotel pays some of the highest water and sewer rates in the country, paying approximately US$0.02 per every gallon used. In a hotel with 439 rooms and high occupancies, this cost is one that needs to be tightly controlled.
The idea, solution
Shirley was watching it rain on the hotel’s third floor terrace and remembered thinking, what a waste. “If only we could somehow harvest and reuse all that water we could really save some money,” he said. “I knew it was the right thing to do and it could have a decent return on investment.”
After a few days of pondering, Shirley called a friend who owned a local plumbing company that he used for all of the hotel’s plumbing projects. He also contacted the director of administration and development at Southern Polytechnic University. Collectively thinking out of the box, they were able to determine the greatest areas of impact the hotel could make on our water sustainability. They also involved the students at Southern Poly Tech, as well.
The outcome: a rain harvest system that collects and stores 30,000 gallons of water. The water is immediately used in the hotel’s cooling tower, allowing the hotel to use less city water. “This was a real-time learning experience and helped form a relationship between the school and the hotel, one from which we hope to develop more energy saving projects,” Shirley added.
Return on investment
Here is how Shirley explains the results:
- The hotel’s third floor roof top surface is 32,000 sq. ft., which is the base line from which the hotel can harvest.
- One inch of rainfall per square foot yields 0.62 gallons and the average rainfall in Atlanta is 50 inches annually.
- The hotel pays US$0.02 per gallon of water and sewer. 32,000 sq. ft. x 0.62 gallons per inch x 50 inches per year = 992,000 gallons per year.
- 992,000 gallons per year x US$0.02626 per gallon = US$26,050 per year in savings.
- US$100,000 costs/US$26,050 per year in savings = 3.84 years to pay back cost of project with annual savings.
The rainwater is the core of the hotel’s harvesting, but condensate and ice machine drains are the icing on the cake. The hotel is currently piping in ice machine drains and condensate drains from all air handlers. In comparison it will harvest two days of cooling tower water each week, which is an equivalent of 30,000 gallons of water during the summer months.
Next on the list for Grand Hyatt Atlanta is grey water.