PNNL latest Commercial models don't align with the ASHRAE 90.1-2019 code
I observed that the latest commercial prototypical buildings don't align with code ASHRAE 90.1-2019. (specially exterior walls). I tried to compare it with the older models which I had downloaded in 2023. I see that the latest medium office building has been assigned with three different wall U values which wasn't the case in older models. Has anyone faced this issue? What is the reason behind this change?
Comments
(just guessing here - link to idf?)
90.1 has almost always had 4 above-grade wall categories/requirements (e.g. "mass", "steel-framed"). Depending on the climate zone, the steel- and wood-framed categories sometimes have the same U-factor requirements. This would boil down the actual number of wall requirements to 3 in some instances. So when I read "3" different wall U-factors, I assume all 3 requirements are likely being evaluated (e.g. GJ vs $). PNNL may have simply picked 1 (out of 3) in previous models, e.g. "steel-framed" for medium office? Hoping PNNL staff can chime in.