Stanford University has recently started using a new heat recovery system. A large research campus such as Stanford University, requires a substantial amount of energy to operate, resulting in a significant amount of Greenhouse Gas emissions and high operating costs, which makes the management of resources a priority.

After a detailed review of campus energy use, researchers identified a simultaneous need for heating and cooling in the university campus. Different rooms require different temperatures depending on what kind of equipment and activities are taking place there. For example, in office spaces temperature needs to be higher than in computer labs. Researchers studied how to collect wasted heat – which is the heat emitted as a byproduct by office equipment during its working process – generated within a building and reuse it in another where more heat is required. This, known as a reheat process, is accomplished through the building hot water hydraulic system, developed by Stanford researchers under the Stanford Energy System Innovation (SESI) project.

The new heating recovery system consists of three heating pumps, two five-million-gallon cold water tanks, and one two-million-gallon hot water tank. Using these facilities, recovered heat is distributed as hot water through water piping in 155 buildings around Stanford’s campus.

The new method developed at Stanford University allows using wasted heat in a more efficient way. The waste heat is collected by the chilled water system to meet simultaneous heating demand and is transported across the central campus to buildings by underground cables and pipelines. Heat recovery pumps transfer waste heat to a hot water tank in the university’s central energy system. Then the hot water is circulated throughout the campus.

The development of this new heat recovery system is expected to bring significant benefits to Stanford University, including:

• • • Reduced overall operating costs;
    • Reduced noise pollution;
    • Reduced Greenhouse Gas emissions by 150,000 tons per year.
    • Reduced water use by 18% in comparison to its 2011 level;
    • Since the new system works by using electricity instead of natural gas, the project supports the diversification of energy supply.

For more information visit: http://sustainable.stanford.edu/campus-action/stanford-energy-system-innovations-sesi.