Project description: This is a LEED NCv2.2 registered project. This existing building includes approximately 90,000 sf of university teaching and research laboratory space and approximately 50,000 sf of office and administrative spaces. The building envelope will remain largely intact and interior lab spaces will be modernized at varying levels. Laboratory spaces: Lighting in some labs will be replaced. Chilled water cooling and steam heating are campus infrastructure systems to remain as is. Major upgrades to infrastructure ventilation systems dedicated to laboratories consist of (1) replacing the predominantly pneumatic constant volume controls to digital variable volume controls, (2) replacing distributed individual constant volume fume and general exhaust fans with a building-wide manifold variable volume exhaust system, (3) replacing most of the constant volume fume hoods to variable flow hoods, (4) replacing constant speed variable pitch vane axial fans with variable speed centrifugal fans and (5) reducing room air exchange rates from an average of about 16 AC/HR to an average of about 8 AC/HR. Office/administration spaces: Air handling systems dedicated to office and administration spaces will remain as is. Lighting and interior architecture will remain as is. Credit EA1 Energy modeling: DOE eQuest modeling software is being employed, using ASHRAE 90.1-2004 Appendix G modeling criteria. Appendix G text appears intended primarily for new systems, with some provisions made for existing systems and equipment. Section G.3.1.2 appears geared toward new systems for baseline building design. Table G.3.1 No. 2. allows exclusion of building parts from the models under certain circumstances. Table G.3.1 No. 10(a) provides direction to use actual system types with actual component capacities and efficiencies for Proposed Building Performance. For Baseline Building Performance, Table G3.1 No. 10 provides direction to use section G.3.1.1, which appears to be geared toward new systems. Table G.3.1 No. 10 does not appear to directly speak to Baseline Building Performance in existing systems. Topics to clarify/confirm: #1: Energy model; Baseline Building Performance: Appendix G and Table G.3.1 appear to be structured to model a proposed design against a baseline building of similar type, with various prescribed minimum efficiencies for baseline system equipment and components. Following this structure it seems logical that retrofits to an existing system should be modeled as-designed for the Proposed Building Performance using the existing system for Baseline Building Performance. The LEED NC 2.2 EA Credit 1 text directly cites this Table G.3.1 Section 10(a) text, speaking to use of "existing system type and actual component capacities". An alternative approach to Table G.3.1 No. 10(a) Baseline Building Performance, however, is to use the as-designed system component capacities and ASHRAE 90.1-2004 equipment efficiencies, for the baseline model. Doing so, however, may apply the Table G.3.1 No. 10 Baseline Building Performance text, potentially intended for new systems, to existing systems. #2: Modeling of existing systems not modified/included in the project scope: ASHRAE 90.1-2004 Appendix G Table 11.3.1 Section 2. Additions and Alterations allows unmodified HVAC systems to be excepted from the energy performance analysis. Credit Interpretation Ruling 10/16/2008 - provides direction that a LEED project\'s boundary should include all building areas, regardless of degrees/absence of modifications. Proposed actions: #1: Credit EA1 Energy model: Use existing system component efficiencies and capacities for the Baseline Building Model fan systems. These would include fans, pumps and motors in ventilation systems dedicated to laboratory spaces. Use the as-designed component efficiencies and capacities for Proposed Building Performance for modified equipment serving laboratories. Unmodified ancillary pumps and fans serving laboratories would be modeled using existing efficiencies and capacities. #2: Credit EA1 modeling of existing systems serving unmodified office and administrative spaces: Include all building areas in the LEED boundary as clarified in the Credit Interpretation Ruling 10/16/2008, for application to all prerequisites and credits. Omit from the EA1 energy model all unmodified HVAC systems serving office and admin spaces that comply with the ASHRAE 90.1-2004 Appendix G Table 11.3.1 Section 2 exception criteria.