Vertical Glazing

Projects must follow 90.1, however, it does not typically require you to meet every prescriptive requirement. The SHGC is not a mandatory provision so it is available for tradeoff as are all building envelope provisions in the climate zone tables. Assuming that you are demonstrating prerequisite compliance with your energy model for EAc1 following Appendix G, you do not need to meet this prescriptive requirement of 90.1.

Hi, How abt in baseline energy modeling, do we have to follow strictly Table5.5? My project falls in Climate Zone 1.The vertical glazing SHGC value of 0.25 in Table 5.5 seems very aggressive which results in energy consumption of proposed design is higher than baseline. In addition, the U value of Roofs and Walls decribed in Table 5.5 are pretty low, which can hardly be met from standard building details commonly adopted in tropical countries. In short, the baseline set in ASHRAE seems quite high standard. Could you please advise? We are trying to get our LEED certification for our vietnam project but then realize we might fail after we started working on the energy modeling. Thank you very much. from someone almost desparate

The baseline must be modeled according to Appendix G which references Table 5.5 so you must model the baseline that way. Not sure about Vietnam but SHGC 0.25 glazing is easily available here. As mentioned above you do not have to meet the prescriptive insulation requirements and can get your savings in the other building systems. Are you certain that the insulation is causing the problem? Did you run some different insulation iterations to see the effect? Sounds to me like you need to identify the major energy using systems and strategies for reducing the energy use associated with them. The intent is to design an energy efficient building, so instead of seeking exceptions to baseline requirements figure out how to make the building use less energy.