Keeping a lid on pollution and energy consumption at Iowa

	Energy and environmental engineer Prasanna Kumar uses his handy hot-wire anemometer to measure the air flow, temperature, and humidity at an air handling unit in the new University Services Building. Photo by Helen Spielbauer.

Kumar’s task is twofold. First, it’s his job to control the emission of pollutants from all campus buildings. Second, he is responsible for cutting energy usage on campus.

In that first capacity, Kumar is celebrating a recent victory. Thanks to his efforts, Iowa recently was granted its Title V Air Operating Permit. It’s a legal milestone signifying that the University is in compliance with the Clean Air Act of 1990.

"We are the first university in the state of Iowa to obtain that permit," Kumar said.

Getting the permit wasn’t just a rubber-stamp process with the Iowa Department of Natural Resources. Kumar studied each source of emissions on campus, every generator, exhaust vent, and smokestack that releases into the open air. Stack location or stack height had to be modified in some buildings.

"It invariably required us to use more efficient equipment, to make changes in the type of equipment we were using, in some cases to raise the stack to a height where the release of pollutants would not affect people," Kumar said. "Two examples are the generator behind the public safety building and the generator behind the water plant, which has a stack of approximately 60 feet from the ground."

Getting that operating permit didn’t mean Kumar could rest on his laurels. Each time a building is built or remodeled, separate construction permits must be obtained for some large air emission sources. Since the University is always doing new construction, it’s a constant process.

When he’s not dealing with pollution, Kumar is the University’s chief energy police officer. We all know somebody who says "Turn off that light" or "Don’t stand in front of the open refrigerator." Kumar does it on a grand scale.

In the last 10 years, the University instituted a number of changes in its efforts to curtail energy use. New campus buildings are designed with more energy-efficient features, while old ones are retrofitted with new technology. New generations of fluorescent lighting have been installed in existing buildings for a saving of up to 25 percent on energy for lighting. Old fan and water pump motors have been retrofitted with variable speed drives. A fan with one speed that frequently turns on and off runs less efficiently than a fan that runs constantly at variable speeds based on the load.

"One of the big energy savers in retrofitting is direct digital control of heating and air conditioning," Kumar said. Traditionally, a building’s heating and air conditioning system recirculates the indoor air, heating or cooling it as necessary. Some high-tech systems instead draw their air from outdoors, allowing for greater exchange of air. The University’s newer systems can do either one, and they’re smart enough to know when to draw in outside air and when to recirculate indoor air. "Anytime the outside air goes down below 55 degrees, instead of cooling air inside, they will draw air from the outside."

These programs work. How well? The main measure of energy consumption is British Thermal Units per gross square foot, or BTU/GSF. In 1988-89, the University used 467,725 BTU/GSF. Ten years later, in 1998-99, that number was reduced to 439,154 BTU/GSF. It was a reduction of about 6.1 percent in energy usage.

"Now, 6.1 percent itself is not impressive," Kumar said. "What makes it impressive is that in the last ten years there has been a lot more research equipment, medical diagostic equipment, and air conditioning equipment added to campus."

It was also a period of mushrooming computer use, which alone represents 5 to 10 percent of the University’s energy cost. Kumar estimates that these added power drains should have pushed the University’s energy costs up by about 15 or 20 percent. So in fact, the nominal reduction of six percent actually represents a real drop of 21 to 26 percent in expected usage.

Kumar is quick to point out that you don’t have to be an engineer to have an impact. "Each of us can contribute to this effort," he said. He welcomes calls from individuals with suggestions on energy saving. Kumar can be reached at (33)5-5122, prasanna-kumar@uiowa.edu.

"More than FSG, or engineers here, or me, it is the users who can make a big difference on campus."

Article by Sam Samuels