Buro Happold pioneers wind driven natural ventilation in US

Buro Happold

16/10/2012 Written by: Silvia Van Wingerden and Jodi Christopher No comments

The use of prevailing winds as an active source of natural ventilation originated some 2,000 years ago, yet today we find the majority of office buildings blasting air conditioning to cool spaces. On two recent projects in California, we designed an engineering solution that incorporated Monodraught Windcatchers, a natural ventilation system not previously used in the United States.

Well established in Europe, the technology was originally developed to take advantage of the temperate north European climate. The solution is simple, the results remarkable, and our analysis showed that the devices could be used in California’s coastal regions with equal success.

The windcatcher ventilation system harnesses the power of prevailing winds, pulling cool air in and pushing warm air out. The system can also be used to provide ‘night purge’ ventilation - cool night air is passed through the building interior, cooling the mass of the structure. The following day this pre cooled thermal mass is able to absorb heat and thereby reduces temperature rises in the space.

The system is now part of a holistic ‘mixed-mode’ design solution for the new headquarters office of Los Angeles based firm, Morphosis Architects. Although the building was not explicitly designed to achieve net-zero carbon emissions, performance of the windcatchers and daylight harvesting strategies have exceeded expectations to the extent that a coveted ‘net-carbon zero’ moniker is within reach. Post occupancy monitoring of the facility has demonstrated the effectiveness of the system in maintaining comfortable temperatures and diluting airborne contaminants, as well as a reduction in the use of a back-up mechanical system.

Buro Happold repeated the successful application of Monodraught Windcatchers on the new headquarters office of San Francisco based design firm, Fuseproject. At Fuseproject the ‘solar boost’ version of the windcatcher provides the sole means of ventilation and cooling for the entire facility. Through detailed building performance analysis we were able to demonstrate that, as part of an integrated passive design strategy including facade upgrades and solar control, the windcatchers could maintain internal comfort conditions for 96% of annual occupied hours.

By using this innovative technology we are able to effectively and naturally ventilate spaces, helping to achieve net-zero sustainability goals and to provide overall occupant comfort.