COOLING TOWERS AND SUSTAINABILITY INTRODUCTION • With a campus of over 100 buildings and 17 million square feet of floor space, UC Berkeley faces a significant heating and cooling demand. • While heating relies on a central steam system, cooling requires an individual system in each building. • Unfortunately, this leads large-scale cooling systems to be costly, difficult to maintain, and energy inefficient. • In this project, we gathered detailed technical data for each individual cooling system. • We then evaluated this data to improve existing cooling tower systems, and minimize their environmental impact.
SUMMARY OF DATA COLLECTED We created a schematic for every single cooling tower system on campus, collected detailed manufacturer data and chemical treatment data, and assembled it all into one large binder. The data inside includes: • 50 unique cooling towers, totaling at over 35000 gallons per minute of flow capacity • 50 chillers • 200+ motors, totaling at over 4000 Horsepower of combined power
COOLING TOWER OPERATION • Hot water enters through the pipe on top of the tower • Water is equally distributed within the tower with a sprayer • Water drips down packing, losing heat due to evaporation • Eliminators prevent water from escaping • Fan removes heat from tower • Cold water collects in the basin, and is pumped out to cool the building
Water loss from Eliminators
Microorganism Growth
Water Loss From Basin
CURRENT SUSTAINABILITY ISSUES
FUTURE STEPS
There are a number of towers on campus near or at the end of their lifespan. Damage and dirt accumulation in a tower, caused by age and improper maintenance, is not only bad for the tower, but risks harm to other equipment and people. These risks include: • Irreversible damage to chillers and heat exchangers due to chemical deposits and corrosion. Replacement can cost upwards of 1 million dollars. • Severely reduced system efficiency. More water needs to be pumped through the tower to remove the same amount of heat, and thus water and energy are wasted. • Spread of diseases. Bacteria, algae and mold can all grow in improperly treated Cooling Towers, and enter building airways. The most infamous of these is Legionnaire’s disease, which has been responsible for hundreds of infections and deaths.
Fortunately, these risks are entirely preventable by simple preventative maintenance. Now that the campus’s engineers have access to a binder of all the essential cooling tower information, they will know exactly how to maintain the towers. Berkeley has already used this data to approve a redesign of Koshland Hall’s cooling system, which could save up to 7 million gallons of water per year. With this degree of savings, the new system will pay for itself in less than 10 years. Hopefully, these savings will provide the motivation for funding the replacement of equally inefficient, wasteful systems.
ACKNOWLEDGEMENTS Sara Shirazi, Chris Roy, Diana Carriger, and Kevin Ng Project by Connor Howerton