ASHRAE 90.1 Navigator - Generate baseline model

[luanaepb]

Hi,

I have a doubt related to the way the software generates the baseline model for Appendix G-90.1-2007 analysis.

As far as I could check through some tests, if the proposed model has more than 40% of window wall ratio, the baseline model is reduced in order to have a 40% wwr. However, does it take into account the percentage of the envelope that is conditioned or semi-conditioned to re-dimension the model, or it simply "sees" the opaque and glazed area?

Thanks!

Luana

[PCully]

Hi,

I'm not sure how a room would be identified as semi-conditioned but the following excerpt from the PRM Navigator User Guide (page 65) seems to suggest that the glazing assignment is based on external wall area

IF after removing the double-skin façade the overall window-to-wall ratio for the entire baseline building exceeds 40%, the newly exposed glazing on facades where the DSF was removed will need to be downsized until the overall 40% requirement is met. (If the proposed building had greater than 40% WWR prior to generating the Baseline building, the glazing area on all exterior facades will have been automatically reduced to meet the requirement.)

Phil

[geshen516]

Hi,

I'm not sure how a room would be identified as semi-conditioned but the following excerpt from the PRM Navigator User Guide (page 65) seems to suggest that the glazing assignment is based on external wall area

IF after removing the double-skin façade the overall window-to-wall ratio for the entire baseline building exceeds 40%, the newly exposed glazing on facades where the DSF was removed will need to be downsized until the overall 40% requirement is met. (If the proposed building had greater than 40% WWR prior to generating the Baseline building, the glazing area on all exterior facades will have been automatically reduced to meet the requirement.)

Phil

according to ashrae 90.1, it shall be the total facade area.
"vertical fenestration area for new buildings and additions shall equal that in the proposed building or 40% of gross above-grade wall area, whichever is smaller"
gross above-grade wall area shall includes the walls for un-conditioned spaces.