Our project is a 15,000 sq.ft. naturally ventilated building (no HVAC system) for assisted senior living, located in an amenable microclimate in Hawaii. For an EAp2 credit inquiry dated 12/21/2002, you have prescribed that the project assumes (for the purpose of energy modeling only) that both the baseline and the proposed project have identical air conditioning systems. Our question is this: If both buildings have identical systems that are being added only for modeling purposes, could we assume the HVAC loads to be unregulated, and subtract them out (for both cases) of our calculations? Perhaps more to the point: although ASHRAE 90.1 says it is not applicable to buildings that are not conditioned, can we still model the remaining regulated energy loads and use the results to achieve EAc1 points?
The modeling protocol presented here is not valid for EAc1 compliance. Please see IDc1 Credit Interpretation Ruling dated 8/1/2003 for additional information and reasoning. The EA TAG continues to research appropriate modeling methodologies for rewarding the design and construction of naturally ventilated buildings. The TAG is looking closely at ASHRAE 90.1-2001 Appendix G as a possible starting point for development of this modeling methodology. Unfortunately, no final determination has been made which enables recognition of this building\'s natural ventilation strategy at this time.