Intent: To properly calculate the energy points available in EA credit 1.1 through 1.10 for connection to an innovative district cooling system in lieu of constructing an independent building cooling system. Background: Cornell University designed and built an innovative campus cooling system called Lake Source Cooling to replace an existing chiller-based central cooling system. Lake Source Cooling\'s pumping system cools the campus chilled water loop using a closed loop heat exchanger system with water withdrawn from the depths of Cayuga Lake, without refrigerants. The overall energy efficiency of this system is extremely high, requiring less than 10% of the electrical energy of a conventional cooling system. This system has won numerous awards for innovation and energy efficiency, including the following:
Centralized utility plants can offer energy savings over dedicated single building systems. However, credit for this strategy cannot be awarded under EAc1 due to limitations in the energy modeling protocol. When selecting the HVAC system for the budget building using Table 11.4.3A, note 5 indicates that when using purchased chilled water is used, the chillers are not explicitly modeled. While the situation described is not using "purchased" chilled water, this HVAC description for the budget building is the closest to the proposed design and should be used for energy modeling purposes. The issue raised by this CIR is not explicitly addressed in either ASHRAE 90.1 or the LEED Energy Modeling Protocol. As such, action in this area may be eligible for an innovation credit to projects that are able to document source energy efficiency realized through connection of a new building to an existing centralized distribution system. This would require the development of a modeling protocol applicable to all projects. The selection of a proper baseline for comparison needs to be consistent and fair. The USGBC will examine this issue and prepare a subsequent ruling to identify a proper methodology for comparison. Applicable internationally.