CU-Boulder Student Energy Audits Suggest Ways To Save Money On Bills For Denver Nonprofit Groups

Published: Nov. 11, 2007

Students at the University of Colorado at Boulder are evaluating the energy efficiency of several Denver buildings run by nonprofit agencies, and their recommendations will be implemented with help from Energy Outreach Colorado, the International Center for Appropriate and Sustainable Technology (iCAST) and the city of Denver.

About 25 students enrolled in Building Energy Audits, a course in civil, environmental and architectural engineering taught by CU-Boulder Professor Moncef Krarti, are working in teams this fall to evaluate 18 buildings used as residential shelters.

Starting with a dozen small buildings under 10,000 square feet and then moving to a handful of larger buildings, the students are doing walk-through evaluations, measuring pressurization and leakage, and recording indoor temperature and humidity fluctuations over time. They also are studying utility data for each building to help determine how energy costs, which are paid by the nonprofit agencies, could be reduced.

Findings from the initial set of audits show high energy losses resulting from cracks around doors, windows, and heating and ventilation equipment; inadequate thermostat controls, and lack of insulation in the walls and ceilings of several buildings, Krarti said.

The students have submitted recommendations on cost-saving measures based on detailed simulation modeling of the audited buildings.

For basic measures such as caulking, weather-stripping, installing programmable thermostats, adding thermal insulation in the ceilings, and insulating hot water pipes, about $25,000 in energy costs could be saved annually with an initial investment of $45,000, Krarti said.

If other measures are taken to improve both the energy efficiency and thermal comfort, such as replacing windows and adding thermal insulation in walls, $57,000 in energy costs could be saved annually for an initial investment of $324,000, he added.

Micah Allen, engineering project manager for iCAST, a Lakewood-based nonprofit, said some basic improvements like caulking and installing programmable thermostats will be made immediately, with more complex upgrades scheduled for December or early next year.

"The City of Denver set aside a budget for upgrades on the order of $500,000, and the students are giving the city a prioritized list of what can provide the biggest bang for the buck," Allen said.

He estimated the students' labor in auditing the building is worth about $70,000 to $80,000 to the project.