ENERGY MODELING GUIDELINES. D. Section Building Automation and Control System Guidelines

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1 ENERGY MODELING GUIDELINES PART 1: GENERAL 1.01 RELATED SECTIONS A. Section Green Building Guidelines B. Section Basic HVAC Requirements C. Section Laboratories D. Section Building Automation and Control System Guidelines 1.02 RELATED RESOURCES A. Cornell University Energy Modeling Template B. Cornell University Life Cycle Costing Template C. Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 Design and Construction, dated August 13, 2010 D. Appendix A: Modeling the District Heating and Cooling Systems of Cornell University for LEED Projects 1.03 INTENT A. Building energy modeling during the design of a building or renovation shall serve several purposes. The primary objective is to inform design decisions in a way that guides the design toward University goals for building performance. It is recognized that the detail and resolution of the model will refine as the design progresses from concept to design development. The objective of this modeling guideline is to yield results that are consistent between projects and more representative of eventual metered utility data. The process is one of continuous improvement; refinements will be made to the modeling guidelines as operating data is collected on modeled buildings. B. The consultant shall perform a Cornell Option 1 Model that models total building energy use and savings against a baseline at the building level, without benefits of central plant efficiencies. This model represents total metered energy inputs in steam (in MMbtu), chilled water (in ton-hours) and electricity (in kw-hr) for building heating, cooling, ventilation systems, service water heating, lighting, DATE: 11/16/2017 DATE: 11/16/2017 Page 1 of 9

2 receptacle loads and process energy use. The performance rating method described in ASHRAE 90.1 Appendix G shall be used for the Cornell Option 1 Model. For this model, the baseline HVAC types shall be modified to be consistent with the purchased energy source. C. For projects pursuing LEED certification, the consultant shall also perform a LEED Option 2 model that models total building energy cost and savings against a baseline with the benefit of central plant efficiencies added. This model represents total energy inputs in natural gas (in therms) and electricity (in kw-hr) for building heating, cooling, ventilation systems, service water heating, lighting, receptacle loads and process energy use. D. This guideline clarifies the expectations with regard to energy modeling for the design team performing work on a Cornell University project. This information will also be inserted into the Consultant s contract DEFINITIONS A. EUI: Energy Utilization (or Use) Index is the measure of the total energy consumed in a building, expressed as energy per gross square foot of building area, typically kbtu/sf/yr. B. kbtu: 10³ Btus (consumption) C. MMbtu: 10⁶ Btus (consumption) D. Therm: 100,000 Btus (consumption) E. MBH = 10³ Btu/h (demand) F. Steam cfh = cubic feet per hour (demand) G. Chilled Water tons = 12,000 btu/h (demand) H. LCCA = Life Cycle Cost Analysis 1.05 OBJECTIVES A. Energy modeling will serve as a tool throughout the design process to evaluate design options and make appropriate choices that support Cornell s pursuit of climate neutrality. B. Process and results will be used for LEED certification, although the primary objective is to evaluate energy use, cost and carbon impact. C. The model will also be used to predict building energy cost for budget planning. DATE: 11/16/2017 DATE: 11/16/2017 Page 2 of 9

3 PART 2: ENERGY MODELING REQUIREMENTS 2.01 GENERAL A. Cornell prefers that modeling consultants use equest or Energy+, DOE based energy modeling software packages, to execute energy models. The modeler will make available the input and output files for Cornell s review and use. The use of other modeling software packages may be approved by Cornell upon specific request. B. Cornell recommends the use of TMY/2 climate data for Binghamton, NY for projects on the Ithaca campus. Deviation from using this data set requires approval from Facilities Engineering. C. The University will make available an Energy Modeling Template in Microsoft Excel format. This document contains worksheets for model inputs, outputs, schedules, and other information that may be useful to modelers. In addition, there are places to input results for Option 1 Models for easy calculation of EUI s, as well as formulas for calculating the results of central plant efficiencies. D. The model should reflect Cornell values for schedules, setpoints, occupancy density, and space loads so there is consistency between modeling phases. If there is a reason to believe schedules for the modeled building will not be in alignment with the schedules defined in the Cornell Energy Modeling Template, the modeler should bring this to the attention of the University and propose more appropriate use schedules. E. The University will also make available a Life Cycle Costing Template in Microsoft Excel format to aid in the development of life cycle studies that serve to evaluate the viability of energy conservation measures. F. For LEED projects, Cornell has developed a companion document to the USGBC Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 Design and Construction, dated August 13, This document, Appendix A: Modeling the District Heating and Cooling Systems of Cornell University for LEED Projects, provides information on the Cornell District Energy Systems and guidance on how to calculate Virtual Heating and Cooling Plants that reflect our Combined Heat and Power and Lake Source Cooling Plants. This document should ALWAYS be uploaded to LEED Online along with all other LEED related documentation. At the request of the LEED reviewer, Cornell will also provide back-up calculations to support the stated efficiencies of the district energy systems. Cornell must approve the LEED model prior to submitting to the USGBC for review. DATE: 11/16/2017 DATE: 11/16/2017 Page 3 of 9

4 G. Review: At the end of each phase, the Cornell Project Manager shall initiate a meeting between the project modeling and engineering team, Facilities Engineering, and Energy and Sustainability. This meeting shall be independent from design reviews and meetings to discuss the status of LEED certification. This meeting shall focus on the review of energy modeling results. If the project is not meeting energy targets, the team shall consider measures to get the project on target ENERGY MODELING PLAN A. Prior to the start of modeling, the consultant shall present an energy modeling plan that describes the intended modeling approach to be used throughout the course of design. This plan must be approved by the University Engineer. The plan shall define the following for each phase of design: 1. Model inputs that are anticipated to be known or assumed at that point of design. 2. Modeling software to be used. 3. The anticipated building and system options that will be evaluated at each phase. 4. Model result level of detail, format and presentation method CONCEPTUAL / PRE-SCHEMATIC PHASE / MASTER PLANNING A. Intent: During this phase, decisions will be made that include building site, orientation, glazing, and massing. The intent of pre-schematic energy modeling is to evaluate concept variations relative to inherent differences in energy consumption of these variations. B. Areas of Study: A Cornell Option 1 model will be performed in this phase. Evaluate the shape of the building for impact on heating and cooling loads. As part of this phase, the architect is required to generate three different massing concepts for the building, as accepted by the Cornell University Architect. Each of these conceptual designs will be modeled during this phase. Cornell expects the massing and envelope design to be optimized before considering mechanical and electrical systems. C. At this point in the process, not much is known about building systems. For this phase, a Shoe Box approach can be used to enable the setup of sensitivity analysis for Façade design. The following variables are typically studied: 1. Façade Orientation 2. Glazing-to-Wall Ratios 3. Wall Insulation Values DATE: 11/16/2017 DATE: 11/16/2017 Page 4 of 9

5 4. Window Assembly U-valve and shading D. Simulation Inputs: 1. Provide key input assumptions (for example, Ventilation Loads, HVAC Type, Lighting Power Density, etc.) in format that conforms easily to the Cornell Energy Modeling Template. Based on the size of the project, the HVAC types shall be consistent with the baseline systems identified in ASHRAE 90.1 Appendix G, but the input energy shall be modified to reflect chilled water and steam use regardless of system type. E. Simulation Outputs: 1. Chilled Water a. Consumption (MMbtu & ton-hours) b. Demand (MBH & tons) 2. Electricity a. Consumption (MMbtu & kw-hrs) b. Demand (MBH & kw) 3. Steam 4. Natural Gas 5. Carbon conversion of energy source use is NOT required. Cornell will perform this calculation SCHEMATIC DESIGN PHASE A. Intent: A Cornell Option 1 model will be performed in this phase. Significant design decisions will be made during the Schematic Design (SD) phase, and it is the intent of SD energy modeling to support informed decisions and to test that the design is on track with EUI goals. Relevant design decisions to be made during this phase include building envelope, mechanical system selection, control sequences of operation, criteria for space conditions, lighting systems and anticipated plug loads. B. A preliminary energy model parametric run is to be performed with up to three variations on HVAC system types. The HVAC types used should be consistent with the baseline systems identified in ASHRAE 90.1 Appendix G, but again the input energy shall be modified to reflect chilled water and steam use regardless of system type. DATE: 11/16/2017 DATE: 11/16/2017 Page 5 of 9

6 C. Areas of Study: 1. Envelope: If not already accomplished in the pre-schematic, concept, or master planning phases, perform a parametric study of wall insulation values and glazing options to optimize the cost/benefit of the envelope. Life Cycle costing shall be performed to arrive at a final decision. Cornell expects the massing and envelope design to be optimized before considering mechanical and electrical systems. 2. Mechanical Systems: Three HVAC system types shall be considered. Cornell shall approve the variations to ensure that range and/or variety is sufficient to make them individually significant. 3. Ventilation: Airflow Reduction Strategies 4. Lighting: Reduction of electric lighting power density and use of daylighting as much as possible. Consider high efficacy lighting and efficient ballasts. Focus on lighting control strategies for each space based on the energy model, such as occupancy and daylight sensors. 5. Renewables: Consideration of renewable energy possibilities. 6. Buildings that are not connected to the Cornell District Energy Systems (DES) shall include modeling of alternate heating and cooling systems, such as ground source heat pumps as well as extension of the campus systems. D. Simulation Inputs: 1. Provide key input assumptions in a format that conforms easily to the Cornell Energy Modeling Template. 2. Provide any calculations that support assumptions. 3. The HVAC system types shall be consistent with the baseline systems identified in ASHRAE 90.1 Appendix G, but the input energy shall be modified to reflect chilled water and steam use regardless of system type. 4. All associated energy use and costs must be included. 5. Identify energy requirements based on the programmatic needs and project goals. E. Simulation Outputs: 1. Parametric Analyses 2. Chilled Water a. Consumption (MMbtu & ton-hours) b. Demand (MBH & tons) 3. Electricity a. Consumption (MMbtu & kw-hrs) b. Demand (MBH & kw) 4. Steam DATE: 11/16/2017 DATE: 11/16/2017 Page 6 of 9

7 5. Natural Gas 6. Carbon conversion of energy source use is NOT required. Cornell will perform this calculation. F. Life Cycle Cost Analyses: Alternatives shall be evaluated using a life cycle cost analysis. The energy model shall be used to determine differences in performance between options and the project cost consultant shall provide input on cost premiums of options DESIGN DEVELOPMENT / CONSTRUCTION DOCUMENTS PHASE A. Intent: The Cornell Option 1 model performed in previous phases will be refined and updated during the Design Development and Construction Document phases. Final decisions will be made on equipment sizing and selection. 1. Sizing of ductwork and piping should result in a refined value for systems pressures and power requirements. 2. Continued work with the user group should result in better information on equipment loads, occupancy schedules and space conditions. 3. Control system strategies will be evaluated during these phases of design. 4. Decisions made regarding glazing, insulation systems and lighting should be tested as part of this updated model. B. During these phases, cost estimates shall be refined and life cycle cost analysis of options should be updated. It is assumed that major system selections were made during the Schematic Design and decisions made during DD and CD will be related to components or system features. C. Areas of Study: 1. Mechanical Systems: Consider variations in system control strategies and components. 2. Lighting: Continue design of electric lighting and use of daylighting strategies. Refine lighting control strategies for each space based on the energy model. D. Simulation Inputs: 1. Provide key input assumptions in a format that conforms easily to the Cornell Energy Modeling Template. 2. Provide any calculations that support assumptions. DATE: 11/16/2017 DATE: 11/16/2017 Page 7 of 9

8 3. The HVAC system types shall be consistent with the baseline systems identified in ASHRAE 90.1 Appendix G, but the input energy shall be modified to reflect chilled water and steam use regardless of system type. 4. All associated energy use and costs must be included. E. Simulation Outputs: 1. Parametric Analyses 2. Chilled Water a. Consumption (MMbtu & ton-hours) b. Demand (MBH & tons) 3. Electricity a. Consumption (MMbtu & kw-hrs) b. Demand (MBH & kw) 4. Steam 5. Natural Gas 6. Carbon conversion of energy source use is NOT required. Cornell will perform this calculation. F. Life Cycle Cost Analyses: Alternatives shall be evaluated using a life cycle cost analysis. The energy model shall be used to determine differences in performance between options and the project cost consultant shall provide input on cost premiums of options LEED ENERGY MODEL A. Intent: For those projects pursuing LEED Certification, at the completion of the Construction Document phase and approval of the Cornell Option 1 Model, the Consultant shall present a LEED Option 2 model that shall incorporate central plant efficiencies, ready for submission to the USGBC. B. Area of Study: Document the Energy Model per the requirements of LEED EA Prerequisite 2: Minimum Energy Performance; and EA Credit 1: Optimize Energy Performance. C. Simulation Inputs: 1. All LEED documentation required to submit for EA Prerequisite 2: Minimum Energy Performance and EA Credit 1: Optimize Energy Performance. DATE: 11/16/2017 DATE: 11/16/2017 Page 8 of 9

9 D. Simulation Outputs: 1. Electricity a. Consumption (MMbtu & kw-hrs) b. Demand (MBH & kw) 2. Natural Gas 3. Carbon conversion of energy source use is NOT required. Cornell will perform this calculation POST OCCUPANCY VERIFICATION A. For Consultants who wish to reconcile their model with actual energy use, Cornell will make available actual metered energy use after 2 years of occupancy, or to coincide with the time period prescribed in the LEED Measurement & Verification Plan. DATE: 11/16/2017 DATE: 11/16/2017 Page 9 of 9

Appendix Energy Guidelines Deliverable Requirements

Appendix Energy Guidelines Deliverable Requirements Appendix 3.3-19 Energy Guidelines Deliverable Requirements 1. I n t r o d u c t i o n The 2008 edition of the University Energy Guidelines are written in support of aggressive campus carbon reduction goals