Our project has three different types roof
1. Sloped roof with a centria metal panel
2. White Roof
3. Green Roof
4. Elevator bulkhead "roof"???
I am assuming that i need the Area weighted average determined first instead of the U-factor for each to input into LEED Minimum Energy Performance Template spreadsheet and ultimately in the energy model as well. Is this correct?
Do I have to condsider other thermal benefits in our enery model for the white roof as well, other than listing the SRI?
Do I have to condsider other thermal benefits in our enery model for the green roof as well in other to maximize the thermal benefits for building?
I maybe be over thinking this part of my question, but will appreciate clarification nonetheless; would the roof of an elevator bulkhead matter in this calculation as well?
Best regards,
Fatou
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
February 20, 2019 - 12:08 pm
Depending on your modeling software you will need to enter some type of reflectance value for each roof type in the model. I would not do a weighted average. You need to model reflectance and U-value to simulate the performance of the different roof types. The elevator roof probably does not matter since the space below it is typically unconditioned. See 90.1 Table G3.1 - 5 for both the proposed and baseline modeling guidance on this issue.
David Eldridge
Energy Efficiency NinjaGrumman/Butkus Associates
67 thumbs up
February 20, 2019 - 1:01 pm
For instance if you were using eQUEST, you'd enter each space in the model with its actual roof design. Then you can view a report in the *.sim file that shows an aggregate total for roofs (and walls, and windows) in the model which you could use to populate the LEED form.