Appendix Energy Guidelines Deliverable Requirements

Transcription

1 Appendix 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 set out by the campus sustainability plan. This supplement to the energy guidelines is meant to explain the reasoning behind the structure of the process as well as to provide guidance on implementing the process successfully. 2. O u t l i n e o f P r o c e s s It is important to be very familiar with the Project Deliverables outlined in the energy standards. Design teams will be required to submit documentation at several points during the design process. Deliverables need to be reviewed by the PU project management team and facilities to ensure the design team has adequate direction and feedback to proceed. The process has been developed to engage the design team and the University team at Pre- Schematic Design. Achieving energy efficiency significantly better than required by ASHRAE requires that attention be paid to building envelope and massing considerations as early as possible. Energy model results should not be construed as precise predictions of absolute building energy usage. They are a tool to understand the relative performance of a design with respect to a baseline. Many assumptions related to the operation of a building are made during the modeling process and often, actual versus predicted energy use will not be the same. Deliverable 1 Pre-Schematic Design Summary Report This report should summarize the project and present the results of massing studies. The goal is to have the design team test various massing schemes using energy analysis. The goal of analysis during Pre-Schematic design is not accuracy, but relative performance from one massing option to another. Coupled with massing studies should be a basic consideration for the building envelope: orientation, thermal performance, quantities, and external shading. The goal is to address any conflicts between aesthetics considerations and energy considerations early on. The Pre-Schematic design energy model should also be used to identify the relative impact of different energy end uses on overall energy consumption. The end use categories are: lighting, cooling, heating, heat rejection, fans, pumps, and process loads. The PU team should provide feedback to the design team on selected energy efficiency measures to test during schematic design. Deliverable 2 Schematic Design Envelope Review 1 The design team should demonstrate that the building envelope meets ASHRAE requirements by using COMcheck. COMcheck is a free program produced by the Department of Energy that requires the design team input the areas and thermal performance of every building envelope component. The program will produce a compliance report indicating whether the building meets or not. Release 8.0 (November 2008) page 1

2 PU should review the compliance report and check that thermal performance values are reasonable. It is recommended that design teams test that the building envelope passes without significant improvements in thermal performance over 90.1 minimum requirements. Designs with high levels of fenestration (>50%) should be carefully scrutinized. Deliverable 3 Schematic Design Energy Model The design team should submit the results of an ASHRAE Appendix G compliant energy model based on the 100% schematic design scheme. Note that at this stage in design, many detailed parameters will not be known. It is common for a design team to exclude exterior lighting and service hot water heating in schematic level models. The goal of the energy analysis at this stage is to track the progress of the design and give the PU team the opportunity to review design assumptions and provide feedback. Deliverable 4 Schematic Design Daylight Review 1 The design team should either submit the results of computer daylight simulation or glazing factor calculations. Keep in mind that excessive daylight quantities can result in glare and associated thermal comfort issues. Deliverable 5 50% Design Development Energy Model The design team should submit the results of an ASHRAE Appendix G compliant energy model based on the 50% design development scheme. The goal of the energy analysis is to track the progress of the design and give the PU team the opportunity to review design assumptions and provide feedback. For this model, a minimum of 6 energy efficiency measures should be tested individually to determine their impact. This is a key opportunity for the project team to eliminate or add features for testing by energy modeling. Deliverable 6 100% Design Development Envelope Review 2 See Envelope Review 1 notes. There should be no major changes to the envelope scheme after 100% design development. Deliverable 7 100% Design Development Daylight Review 2 The design team should either submit the results of computer daylight simulation or glazing factor calculations. Deliverable 8 100% Design Development Energy Model The design team should submit the results of an ASHRAE Appendix G compliant energy model based on the 100% design development scheme. The design team should not proceed into construction documents until the energy efficiency measures included in this model have been accepted by Princeton University. Deliverable 9 85% Construction Documents Package The design team should submit the results of an ASHRAE Appendix G compliant energy model based on the 85% construction documents scheme. The model should include performance values based on actual equipment selections and calculations. The results of this model will be used for reporting and comparison to other projects. Release 8.0 (November 2008) page 2

3 The design team should also submit a COMcheck compliance report, the glazing factor calculation spreadsheet, and the fan power calculation spreadsheet. 3. A u d i t i n g Energy modeling requires the input of thousands of parameters. The Input/Output spreadsheet (Appendix ) has been developed to allow for review of key inputs and outputs in one selfcontained Excel workbook. Portions of the spreadsheet are created to align with the US Green Building Council s LEED-NC EA Credit 1 documentation requirements. Items to check Are building envelope thermal properties reasonable? U-values for fenestration are often incorrectly input. Center-of-glass U-values, rather than assembly U-values are incorrectly used. For example, a window with center-of-glass U-value of 0.29 may have an assembly U-value of 0.45, due to edge and frame effects. Reference: ASHRAE Fundamentals Fenestration Chapter. Check that the number of hours that load is not met is not greater than 300 total and that there is no more than 50 hour difference between the baseline and proposed case. Check that the correct weather location has been used (Trenton, NJ). Release 8.0 (November 2008) page 3

4 Compare the building source energy consumption to the ranges provided in the following table. These are approximate measures and are intended as an order of magnitude check. Slight deviations from these ranges should be questioned, but are not necessarily indications of poor modeling or high relative energy use. Building Type Source Energy (kbtu/sf/yr) Reference (see below) Academic (Classroom) Administrative (Office/Meeting) Athletic Computing Center Dining Healthcare Laboratory Chemical Physical Biological Chemical/Biological Combination/Others Library Museum Other Performing Arts Residential Retail CBECS, Northeast Region, Education Category 2003, Primary Energy 2. Labs21 Benchmarking Tool, Climate Zones 4A and 5A 3. Architecture 2030 Goals, Based on CBECS EPA Target Finder, Based on CBECS Estimate based on other building types Check that the receptacle load is the same between the baseline and proposed model or that justification is given as to why they are different. Check that exterior lighting and service hot water heating are included in the 100% DD and 85% CD model. 4. E x t e r n a l R e p o r t G u i d a n c e In the Input/Output spreadsheet, energy modeling results will be automatically formatted to produce a single-sheet summary of energy performance. The following components are included: Project Information o Building Name official Princeton University building name. o Building Description description of the building use (e.g. lab, classroom, library, etc.). o Gross Square Footage building area calculated based on Princeton University standards. o Date of Completion this can be the expected or actual date of completion. Release 8.0 (November 2008) page 4

5 Energy Metrics o Site Energy Use site energy use computed by energy modeling. These numbers will tend to be higher then those listed in Energy Information Administration numbers, due to use of purchased chilled water. EIA numbers were developed based on stand-alone buildings that primarily use electricity and natural gas only. o Source Energy Use site energy use computed by energy modeling is notionally converted to source energy use using the following resource utilization factors (RUFs) computed in the utility rate structure spreadsheet: Chilled water 152.5% Electricity 34% Steam 108.4% Natural gas 100% Fuel oil 100% o Energy Star Target Finder Score this is an Energy Star rating determined using the Energy Star Target Finder website located at: o ASHRAE Appendix G this is the official percentage improvement over Appendix G. This can be compared to targets for the LEED-NC rating system: o Cost Neutral Plant this is the percentage improvement of the proposed design over the baseline with use of purchased chilled water in both cases. This metric allows for a cost neutral comparison of cooling energy use. o PSEG Electric/Gas Baseline this is the percentage of improvement of the proposed design over a baseline that assumes PSEG electricity and natural gas rates. This case gives an indication of the cost savings associated with use of Princeton University s advanced cogeneration plant. o Renewable Energy Contribution this is the percentage contribution of renewable energy on a cost basis. This can be compared to targets for the LEED rating system. Carbon Metrics o Carbon Emissions Avoided this represents the metric tons of carbon emissions avoided based on results of energy modeling and the ASHRAE Appendix G compliant case. Emissions are calculated using the carbon rate structure in Appendix o % of Campus Target the percentage of the project s estimated carbon emissions compared to a 25,000 metric ton CO 2 allowance for new construction since Energy Efficiency Measures o The top five energy efficiency measures for the project should be listed. Energy Graphs o Proposed Case End Use Breakdown this pie chart shows the percentage contribution of every end use computed by typical energy modeling programs. Release 8.0 (November 2008) page 5

6 o Electricity Demand by End Use this bar chart shows the peak electricity demand computed by energy modeling for each end use. o Fuel Demand by End Use this bar chart shows peak fuel demand computed by energy modeling for each end use. This chart includes chilled water, steam, fuel oil, and natural gas components. o Source Energy Consumption by End Use this bar chart shows annual source energy consumption computed by energy modeling for each end use. Site energy is converted to source energy using the resource utilization factors described above. Release 8.0 (November 2008) page 6