Building Reuse: Modern Tools, Modern Performance--Predicting Facade Performance in Reuse and Refurbishment Design
Scott Bondi, Ph.D., P.E., LEED® AP, Arup
Neil McClelland, CPEng, Arup
Tali Mejicovsky, P.E., CPEng, LEED® AP, Arup
Reuse of existing building stock is vital to sustainability. Retain components that can continue to perform. Remove and replace those than can not. Retrofit and refurbish those that are in between
Often these goals are in conflict with cost, aesthetics. It is labor intensive to retain over demolish the work and often conflicts with how contracts are awarded in construction.
This presentation centered around two topics. The tools used for facade and glazing design, namely Laurence Berkley National Laboratory’s Window, Therm and Optics and a demonstration on how they can help design glazing and window assemblies.
To open, the discussion centered on some of the codes involved. These include the National Fenestration Rating Council (FNRC) referenced by ASHRAE 90.1 which in turn refers to LBNL suite of software.
Next, they put a brief spot light on the limitations to what the standards and software. NFRC doesn't very well cover louvered openings or grazing systems with integrated (internal) shading devices. The applications that use U-value have a hard time with double-skin systems. Also, applications that use the Solar Heat Gain Coefficient (SHGC) do not take into consideration shading devices or light shelves.
Finally, the talk honed in on some methodologies. First, one must understand external conditions. This includes weather data and weather history. Second, one must understand internal conditions. Using computation fluid dynamics (CFD) modeling is a great way to see what is happening with temperature and airflow inside the building. Then use the tools from LBNL to create the right façade and glazing system to meet the requirements. And don't forget to do real life testing of mockups.