Hi,

I’m currently using Hevacomp Design Database for generating (Part L) BRUKL document for one of my projects.

Couple of rooms in my building are exceeding solar gain limits. I understand this is due to the orientation of the building and the G-value of the glazing.

I tried applying the internal blind to the glazing but some default data in the glazing database does not seems to agree with the computed glazing properties.

For example default glazing type 8 has the same glazing construction as type 20. The only different is type 20 having internal blinds. Please see pictures below for type 8  & type 20.

In default type 8, glazing properties are U-value 1.5, light transmission 0.63, shading coefficient 0.57 and SHGC (G-value) 0.5 which is very similar to computed glazing properties based on the construction U-value 1.469 & G-value 0.6454.

However, in type 20, glazing properties G-value is completely different from computed glazing properties based on the construction. Computed glazing G-value is showing 0.2241 while the glazing properties SHGC (G-value) is at 0.5.

Is it safe to overwrite the type 20  SHGC (G-value) in glazing properties to the same value as the G-value shown in the computed glazing properties based on the type of blind assigned ?

From what I read on the forum, for Part L, we just need to input the U-value, Lighting Transmission, Shading Coefficient & the SHGC (G-value) figures from the manufacturer.

To incorporate the internal blind shading to Part L calculation for solar gain limits, is it safe to overwrite the Shading Coefficient & the G-value of the glazing properties with the G-value from computed glazing data with the type of blind used?

Best Regards,