Built in 1992, the Medical School Lab Surge (MSLS), or Lucas Center, is a 143,000-square-foot School of Medicine building housing clinical diagnostic scanning equipment, offices, and laboratories. Its energy bill is over $2.5 million per year, making it one of the highest energy-using buildings on campus. An energy study conducted through the Whole Building Energy Retrofit Program in partnership with the Office of Facilities Planning and Management identified an opportunity to save significant energy by optimizing air flows in the laboratory spaces. The main supply fans to the lab areas were delivering air at 105,000 cubic feet per minute (cfm) based on outdated standards for air change rates in laboratories. By installing new variable frequency drives on supply and exhaust fans and resetting the air flows to meet Stanford’s current lab design guide, it was possible to reduce the air flow rate to 76,000 cfm, a 28% reduction. This change will reduce use of both fan energy and the hot water and chilled water used to condition outside air. The estimated savings are 443,000 kWh/yr of electricity, 4,020,000 MBtu/yr of hot water, and 81,300 ton-hrs/yr of chilled water, for a cost saving of $262,000 per year. With a payback of under one year, the School of Medicine receieved a full rebate for the project from ERP.