System Retrofit: Water Street Bagel

In order to mitigate the cold draft through openings, our retrofit design pays extra attention to airtightness. The PHIUS standard for airtightness is 0.060 CFM per ft making up the basis for our proposal. We expect that this will noticeably increase thermal comfort in the space.

In an attempt to further increase thermal comfort, the thermal capabilities of the walls and windows have been thoroughly considered. We have found windows that have a relatively high T value and solar heat gain coefficient (SHGC). The window of choice is the Zenith Series ZR-6 from Alpen: U-value 0.14, R-value 7.1, SHGC 0.46, VT 0.56. This performance is in line with PHIUS standards for a passive retrofit project in our region.