Our LEED project occupies 30% of the total building floor area. The energy model modeled the entire building due to a central boiler and condenser water plant. Central air handling units serve multiple tenants. In determining the two year HVAC electrical use we propose using a square footage percentage (tenant floor area/total building floor area) because the tenant space HVAC electricity use cannot be accurately separated out of the entire building HVAC electricity use.
Does anyone have experience with this issue and is the correct approach? Thanks!