I’d appreciate it if you could reply the following questions:
1- A building code requires: Thermal Transmittance (Summer U value) U= 1.9 W/m2K (max) for glazing elements performance.
I’m wondering what number to assign to the “_U_Value” input of the EPWindowMat component. The Honeybee hint tells that it should represent the conductivity of the window in W/mK, and it refers to NFRC’s U Factor under winter conditions.
On the other hand here NFRC defines: “U-factor indicates how much energy will be lost from a building through its windows by specifying how many BTUs can pass through one square foot of material in an hour.”
I’m a bit confused what unit and what number to assign.
2- By knowing a Summer U Value, is it possible to estimate the Winter one?