Forum discussion
NC-v4 EAp2: Minimum energy performance
Dear LEEDUser friends,
for a project with district systems where Option 1, Path 1 will be implemented how will be the HVAC efficiencies for the proposed model defined? Appendix G, G3.1.1.1,2,3 does not make reference to efficiencies. Could you please assist?
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Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 16, 2023 - 9:18 am
Model the baseline building plant with conventional equipment as you would do for any other LEED project. Efficiencies come from the appropriate table in Table 6.8.1x.
Charalampos Giannikopoulos
Senior Sustainability ConsultantDCarbon
84 thumbs up
March 16, 2023 - 11:24 am
Hi Marcus, thank you for your response. This is totally understood as far as the baseline model is concerned. However, how will efficiencies for the proposed model be defined in this case?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 16, 2023 - 11:37 am
The v4 Reference Guide contains the DES guidance. I tindicates that there are three options relative to the porposed efficiency - monitored data, engineering analysis or default values. So basically you figure out the actual plant efficiency or you use the default values.
Charalampos Giannikopoulos
Senior Sustainability ConsultantDCarbon
84 thumbs up
March 16, 2023 - 12:28 pm
Indeed, but since we are going for Option 1, Path 1, there is no specific information about "proposed" efficiencies for this Path? How should we treat this situation?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 16, 2023 - 12:50 pm
Under Appendix G the proposed is almost always modeled as designed or as they currently exist. So you figure out the actual efficiencies or use the default values.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 16, 2023 - 1:03 pm
There is a formula to use in the Reference Guide.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 16, 2023 - 1:07 pm
I might be mixing things up. If by Path 1 you are referring to the purchased heating/cooling method then the efficiency of the plant does not matter since you are only accounting for the energy use once it enters the building.