Elimination of Mechanical Air Conditioning It is widely recognized that the ASHRAE 90.1 and Title 24 energy codes are designed for compliance and do not always allow project teams to report a complete picture of their efforts to conserve energy. An example would be a building designed without air conditioning. The energy modeling software approved for ASHRAE and Title 24 requires that systems in the baseline building match the as-designed systems. Usually, a project can get credit for using more efficient systems but not for eliminating systems completely. We have eliminated air conditioning in a major portion of our building by going to natural ventilation. We propose to demonstrate that removing mechanical air conditioning from this space will reduce our energy cost by at least 5% over the conditioned alternative and to apply for an Innovation Credit, since this effort is not rewarded in the energy model for EACr1. Is this an acceptable approach to an Innovation Point?
While the design and construction of naturally ventilated buildings is a subject that the Energy and Atmosphere TAG is tracking with a great deal of interest, the uncertainties pertaining to fundamental design and performance parameters make their adjudication, within the framework of LEED, extremely challenging. Assignment of an appropriate baseline condition off of which Energy Optimization (EAc1) can be granted depends a great deal on establishment of acceptable comfort parameters in both the baseline (mechanically ventilated) and design (naturally ventilated) cases. These uncertainties make consideration of natural ventilation strategies for award of a LEED ID Credit equally challenging. The project team has indicated that they have eliminated mechanical air conditioning in a \'major portion\' of their building by naturally ventilating the space. While this is indeed a laudable achievement, insufficient information has been submitted on the activities this space supports and no evidence that, absent mechanical space conditioning, the building will be able to support reasonable levels of comfort for the building occupants has been submitted. Absent detailed occupant comfort information, favorable guidance of the possibility for award of an Innovation in Design Credit in this instance cannot be given. In general, the TAG feels that effective natural ventilation of an otherwise mechanically controlled space deserves recognition within the framework of LEED, but not until generally accepted guidelines on building performance against which performance of a proposed system can be judged.