July 10 , 2006
FM doing its part through creative conservation
BY barbara stark
Conservation is a key component of sustainability. Emory’s sustainability vision defines sustainability as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” One of the goals set forth in this vision calls for a 25 percent reduction in energy consumption by the year 2015. This is no small feat and will take a concerted effort on all of our parts to achieve.
Last fiscal year, Emory spent more than $30 million in utility bills. If we had put forth minimal collective effort and conserved even one percent of that consumption, we would have saved $300,000. It’s estimated that this year’s utility expenditure will exceed $40 million. Combine that with plans for campus expansion, and it’s plain to see why concentrating on lowering our consumption is so important and can have such a significant impact. But becoming more energy conscious and lowering our consumption is not simply about saving money. It’s about doing the right thing. It’s about preparing for the future.
Remember the days of the window air conditioning units? How they constantly built up and dripped with condensate water? Or better yet, think of a glass of iced tea on a warm summer’s day—condensation rapidly and repetitively builds up on the outside of the glass, trickling down to the table and onto the ground. Both the window unit and glass of iced tea produce a lot of condensation. But that is just one window unit, one glass of iced tea.
In order to condition a building’s air so that it’s comfortable to the occupants, the warm, outside air is cooled by forcing it across coils through which chilled water is piped. Due to the delicate nature of the work performed in many of Emory’s facilities, stringent standards require that 100 percent of the air used to cool the building is pulled in from the outside—that same warm, humid air that causes your iced tea glass to “sweat” so profusely. Imagine the amount of condensation produced by an air conditioning system designed to cool a building logging in at 325,000 square feet, such as the Whitehead Research Building or the new Pediatrics Building, which measures 156,500 square feet. When these massive units are operational, large volumes of condensation forms on the cooling coils. In fact, Emory has measured this condensation—the Whitehead and Pediatrics buildings produce about 4.7 million and 2.5 million gallons of “sweat” per year, respectively. That’s 7.2 million gallons of condensation in only one year—from just two buildings!
Emory has implemented a method to recover and recycle the condensation produced in cooling air. This has multiple benefits. First, the act of recycling means that Emory is able to purchase less water from the county. Second, it minimizes the number of times that the water is filtered through a treatment facility, and finally, it decreases the volume of water siphoned from the Chattahoochee River.
Instead of flushing condensate water back into the sanitary system as is the standard design for most commercial buildings, Emory is able to pipe this water back into its cooling towers to be used as makeup water. Cooling towers are an instrumental part of an industrial cooling system and require a certain amount of water to keep them operational. Water evaporates or is otherwise lost to the atmosphere during the cooling process and “makeup” water must constantly be added to the cooling towers to keep them operational. Most commercial systems purchase “makeup” water from the county. By recovering the condensation from the coils and recycling it into the cooling towers, Emory is saved the expense in having to purchase water from Dekalb County.
In addition to monetary savings, because condensation is clean water, it does not have to be treated post collection or prior to use. In a typical commercial building, condensation would be routed back into the sanitary system, where it would join with water from other sources. However, unlike the water it joins, which requires specialized treatment before it can be returned to the Chattahoochee River, condensation collected off the coils is clean—save, perhaps, a little dust or dirt.
Water from the Chattahoochee River is used all around metro Atlanta and the surrounding areas for drinking water, irrigation, swimming pools. Especially in times of drought, something experienced quite often in Georgia, water becomes a precious resource. Anything we can do to conserve this precious resource and the associated energy consumption rates is a step closer to providing a better environment for future generations.
The combined 7.2 million gallons of water recycled from the Whitehead and Pediatrics Buildings is 7.2 million gallons that did not have to be processed and treated at a water treatment facility; it’s 7.2 million gallons that were not poured back into the sanitation system, avoiding the energy required for treatment to prepare it for distribution; and it’s 7.2 million gallons of water that did not have to be siphoned from the Chattahoochee River.
Emory’s commitment to sustainability is not just about saving money, it’s about “doing the right thing” for the environment and the future.