APPENDIX 8-G. USER INSTRUCTIONS FOR REBUTTABLE PAYBACK ANALYSIS SPREADSHEET TABLE OF CONTENTS 8-G.1 USER INSTRUCTIONS .......................................................................................8-G-1 8-G.2 STARTUP..............................................................................................................8-G-1 8-G.3 DESCRIPTION OF REBUTTABLE PAYBACK ANALYSIS WORKSHEETS.....................................................................................................8-G-1 8-G.4 BASIC INSTRUCTIONS FOR OPERATING THE REBUTTABLE PAYBACK WORKSHEETS.................................................................................8-G-2 LIST OF TABLES Table 8-G.2.1 List of Rebuttable Payback Analysis Spreadsheets ...................................8-G-1

8-G-iAPPENDIX 8-G. USER INSTRUCTIONS FOR REBUTTABLE PAYBACK ANALYSIS SPREADSHEET 8-G.1	 USER INSTRUCTIONS The results obtained in this analysis can be examined and reproduced using the Microsoft Excel spreadsheets accessible on the Internet from DOE's Heating Products Rulemaking page: http://www.eere.energy.gov/buildings/appliance_standards/. From that page, follow the links to the ANOPR phase and then to the Analytical Tools. The Rebuttable Payback Analysis spreadsheet is part of the overall Engineering Analysis spreadsheet. 8-G.2	 STARTUP DOE named the spreadsheets for the product classes and subgroup analysis if applicable. The spreadsheets enable users to perform rebuttable payback analysis of residential water heaters, direct heating equipment and pool heaters. A separate spreadsheet exists for each of the product classes. Table 8-G.2.1 lists all rebuttable payback analysis spreadsheets used in this analysis. Table 8-G.2.1 List of Rebuttable Payback Analysis Spreadsheets Filename Description WH_Gas_(STORAGE)_EngSpreadsheet.xls Gas-fired Storage Water Heater WH_Elec_EngSpreadsheet.xls Electric Water Heater WH_Elec_EngSpreadsheet.xls Oil-fired Water Heater WH_Gas_(Instantaneous)_EngSpreadsheet.xlsGas Instantaneous Water Heater PH_EngSpreadsheet.xls Pool Heater DHE_EngSpreadsheet.xls DHE Products To examine the spreadsheets, DOE assumes that the user has access to a personal computer (PC) with a hardware configuration capable of running Windows NT/2000/XP. The Heating Products Rebuttable Payback Analysis spreadsheets require Microsoft Excel 2000 or later installed under the Windows operating system. 8-G.3	 DESCRIPTION OF REBUTTABLE PAYBACK ANALYSIS WORKSHEETS This workbook contains one introductory worksheet, one data worksheet and one engineering worksheet. One additional worksheet utilizes DOE water heater test procedure to calculate parameters used in the energy use calculations and another worksheet lists and defines equations and variables used. The Rebuttable Payback Analysis spreadsheet consists of the following worksheets: Introduction Contains the instructions for using the spreadsheet.

8-G-1Data Contains the input selections, the description of variables and data sources. Engineering Contains the total and incremental manufacturer costs, retail prices, the Worksheet installation costs, the repair and maintenance costs, the energy use calculations, and the simple payback period calculations at each efficiency level. Energy Use Utilizes DOE water heater, pool heater, or DHE test procedure to Calculations calculate parameters used in the energy use calculations. Worksheet Definitions Lists and define equations and variables used in the energy use Worksheet calculations worksheet. Efficiency Level For gas-fired storage, electric, and oil-fired water heater spreadsheets Equations contains the calculations for the coefficients for each efficiency level. Table-Lookup For DHE spreadsheet only, contains the DOE test procedure tables to calculate Average Typical Heating Requirements (RDHR) and Heat Output Ratios. 8-G.4	 BASIC INSTRUCTIONS FOR OPERATING THE REBUTTABLE PAYBACK WORKSHEETS Basic instructions for operating the Rebuttable Payback Analysis worksheets are as follows: The Engineering Spreadsheet shows the results from the Rebuttable Payback Analysis. The spreadsheet shows the efficiency levels considered in the analysis and includes sections about the cost data, energy use data, and the final column shows the Rebuttable Payback results. The Energy Use Calculation worksheet shows the detailed Energy Use Calculations from the product-specific DOE test procedure. The results for electric and gas use are provided separately. The Data worksheet includes all parameters used to calculate the Rebuttable Payback.

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