Never mind lighting and insulation… what about HVAC motors?
February 16, 2012 - Energy efficiency efforts tend to focus on things such as lighting and insulation, but Sadrul Ula argues that motors that run HVAC systems are the largest users of energy in buildings. He says motor-related efficiency requirements are relatively lax, and he’s trying to change that.
By Anthony Capkun
Ula is research faculty at the University of California, Riverside’s Bourns College of Engineering Center for Environmental Research and Technology (CE-CERT). He recently received a $385,000 grant from the California Energy Commission to evaluate the efficiency of HVAC motors in buildings through testing onsite and in a soon-to-be built facility at CE-CERT.
“Everyone turns off lights or bathroom fans,” said Ula, who is also managing director of the Winston Chung Global Energy Center at CE-CERT, “but no one turns off motors. The awareness is not there.”
In California, nearly 47% of electrical energy consumption was used by commercial buildings. Motors that create that energy tend to operate at 5-10% below optimal efficiency, Ula said. Increasing that efficiency can have enormous implications; a 5% reduction in energy use in California’s commercial sector is equivalent to 6 billion kWh savings per year, or the annual output of two to three average-sized power plants.
As another example, a 700-hp motor pumping water in a municipal water supply system that runs at 75% efficiency for 10 years will consume about $5 million in electricity. With a 5% increase in efficiency, $250,000 in electricity costs could be saved during those 10 years.
Some experts, including Ula and others at the CE-CERT, believe the lack of attention to proper sizing and efficiency evaluation of large HVAC motors is a major reason why HVAC systems in commercial buildings in California use 47% of power generated. The national average is 36%.
With the grant, Ula and two co-principal investigators—Matthew Barth, director of CE-CERT and an electrical engineering professor, and Alfredo Martinez Morales, managing director of the Southern California Research Initiative for Solar Energy at CE-CERT, as well as graduate and undergraduate students—have three objectives:
One, measure energy use of large HVAC motors onsite under actual operating conditions in office, institutional and commercial buildings. They plan to start with buildings on campus, move to off-campus government buildings in the Riverside area and eventually test building in other parts of the state, to take into account different weather conditions.
Two, they plan to set up a large motor testing facility at CE-CERT. The new independent test facility will be the first of its kind in California and only the third in the United States. Other facilities are located in Oregon and North Carolina.
Three, evaluate commercial and in-house software used by architectural and engineering firms designing HVAC systems.