If the skylight area is greater than 5% of the roof area, what is the U-Value to be considered for the baseline model? ASHRAE 90.1-2010 states the U-Values for skylight only upto 5% of roof area.
I have read other similar threads on this which recommend using the PRM to demonstrate compliance.
However, the question is whether the baseline model should only be modelled with 5% of roof area with skylight or can the skylight area be identical to the proposed?
Similarly, the v4 MEPC Sheet only provides an option to select skylight type upto 5% of roof area in the dropdown for the baseline model. If a different U-Value is to be used for the skylight exceeding the 5% threshold, how should this be input in the MEPC?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
December 6, 2024 - 9:49 am
If the proposed skylight area is greater than 5% then it is modeled as designed and the baseline skylight area is reduced to 5%. Then use the skylight values for the baseline in Tables 5.5-X.