Rating System

LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: Schools, LEED BD+C: Schools, LEED BD+C: Core and Shell, LEED BD+C: Core and Shell

Rating System Version

v2 - LEED 2.0, v2 - LEED 2.2, v2 - LEED 2.2, v3 - LEED 2009, v2 - Schools 2007, v3 - LEED 2009, v2 - LEED 2.0, v3 - LEED 2009

Inquiry

The project building is a naturally ventilated building that does not have a mechanical air handling system. For the EAc1 submittal ASHRAE 90.1-1999 requires that the building be modeled with air-conditioning, even though there is no air-conditioning equipment. EAc6 requires that the green power purchase contract be based on the DEC" value provided in the EAc1 submittal. In the case of naturally ventilated buildings, it seems unreasonable to be required to purchase green power for equipment that is not installed. We propose that for this project, a naturally ventilated building without air handling equipment, the green power purchase contract should be based on an adjusted value equal to the DEC" value minus the cooling energy use of the building, as obtained from the energy simulation summary output. If a Green Power purchase contract, that meets the requirements of EAc6, is based on the adjusted DEC" then the modeled net electricity use for the building will be provided by grid-source, renewable energy technologies on a net zero pollution basis, meeting the intent of the credit to: "Encourage the development and use of grid-source, renewable energy technologies on a net zero pollution basis." As ASHRAE 90.1 is not written for naturally ventilated buildings we feel that it is of paramount importance to avoid penalizing naturally ventilated buildings that are consuming considerably less energy than the conventionally air-conditioned buildings for which ASHRAE 90.1 was written. Is DEC" minus the cooling energy, as obtained from the energy simulation results, an appropriate baseline amount for the purpose of a green power purchase contract for naturally ventilated buildings without air handling equipment?