APPENDIX 8A. USER INSTRUCTIONS FOR LCC AND PBP SPREADSHEETS

TABLE OF CONTENTS

8A.1 INTRODUCTION .................................................................................................. 8A-1 8A.2 SPREADSHEET WORKSHEETS......................................................................... 8A-1 8A.3 BASIC INSTRUCTIONS....................................................................................... 8A-2

8A-iAPPENDIX 8A. USER INSTRUCTIONS FOR LCC AND PBP SPREADSHEET

8A.1 INTRODUCTION
It is possible to examine and reproduce the de tailed results of the life-cycle cost (LCC) and payback period (PBP) analyses using a Micr osoft Excel spreadsheet available on the U.S. Department of Energy’s website at: http://www.eere.energy.gov/build ings/appliance_standards /. To fully execute the spreadsheet requires both Microsoft Excel and Crystal Ball software. Both applications are commercially availa ble. Crystal Ball is available at http://www.decisioneering.com

. The spreadsheet posted on the DOE website re presents the latest version and has been tested with Microsoft Excel 2003.

8A.2 SPREADSHEET WORKSHEETS

The commercial clothes washer LCC and PB P spreadsheet or workbook consists of the following worksheets:

LCC Summary Contains the input selections and a summary table of energy use, operating costs, LCC, and Payback. This worksheet also works as an interface between user inputs a nd the rest of the worksheets -- do not modify this sheet.

Usage Contains the clothes washer us age data in terms of cycles per day for multifamily and laundromat applications.

Energy and Water Use Contains the machine energy and water use, dryer energy use, and the water heating energy use data for the various design options.

Base Case Eff Dist Contains market share efficiency data for commercial clothes washers.

Equipment Price Contains manufacturer price da ta for commercial clothes washer units for the considered design options. Also includes the wholesale, general contractor, m echanical contractor, and national accounts mark-ups, the sales tax, and the installation price.

Energy and Water Price Contains regional energy and wate r prices for the reference year.

Energy Price Trends Contains the electricity and natural gas price trends for the reference, high, and low economic growth scenarios based on AEO 2007.
8A-1Water Price Trend Contains the historical water pric e trend that is used to forecast future water price.

Discount Rate Contains data from which an average discount rate and a distribution of discount rates are determined.

Lifetime Contains the survival functi on for commercial clothes washers and their average lifetime in years.

8A.3 BASIC INSTRUCTIONS
Basic instructions for operating the LCC spreadsheets are as follows:

1. Once you have downloaded the LCC file from the Web, open the file using Excel. At the bottom, click on the tab for sheet LCC Summary.

2. Use Excel’s “View/Zoom” commands at the t op menu bar to change the size of the display to make it fit your monitor.

3. The user interacts with the spreadsheet by clicking choices or entering data using the graphical interface that comes with the spr eadsheet. Select choices from the various inputs listed under "User Options" heading.

4. Under the "User Options" heading, select c hoices from the selection buttons and boxes for the following: (1) type of calculation (Sample or Crys tal Ball®), (2) energy price Trend, (3) start year, (4) efficiency market share scenario, and (5 ) manufacturing cost. A new discount rate or lifetime can also be entered if a value ot her than the default value or default distribution is wanted; however, th is changes the code. As a result, the Department does not recommend saving the sp readsheet after the code is changed.

5. To change inputs listed under "User Input", sel ect the input you wish to change by either clicking on the appropriate button or selecti ng the appropriate input from the input box.

6. This spreadsheet gives the user two types of calculation methods:

a. If the "Sample Calc" is selected, then all calculations are performed for single input values, usually an average. The new result s are shown on the same sheet as soon as the new values are entered.

b. Alternately, if the "CB Calculation" is sele cted, the spreadsheet generates results that are distributions. Some of th e inputs are also distributions . The results from the LCC distribution are shown as singl e values and refer only to the results from the last Monte Carlo sample and are therefore not m eaningful. To run the distribution version

8A-2of the spreadsheet, the Microsoft Excel® ad d-in software called Crystal Ball® must be enabled.

To produce sensitivity results using Crystal Ball, simply select R un from the Run menu (on the menu bar). To make basic changes in the run sequence, including altering the number of trials, select Run Preferences from the Run menu. After each simulation run, the user needs to select Reset (also from the Run menu) before Run can be selected again. Once Crystal Ball has completed its run sequence it will produce a series of distributions. Using the menu bars on the distribution results, it is possi ble to obtain further statistica l information. The time taken to complete a run sequence can be reduced by mi nimizing the Crystal Ball window in Microsoft Excel. A step-by-step summary of the procedure for running a distribution analysis is outlined below:

1. Find the Crystal Ball toolbar (at top of screen)

2. Click on Run from the menu bar

3. Select Run Preferences and choos e from the following choices:

a. Monte Carlo a b. Latin Hypercube (recommended)

c. Initial seed choices and whether you want it to be constant between runs d. Select number of Monte Carl o Trials (DOE suggests 10,000).

4. To run the simulation, follow the followi ng sequence (on the Cr ystal Ball toolbar)

Run Reset Run

5. Now wait until the program informs you that the simulation is completed.

The following instructions are provided to view the output genera ted by Crystal Ball.

1. After the simulation has finished, to see th e distribution charts generated, click on the Windows tab bar that is labeled Crystal Ball.

2. The life-cycle cost savings and payback pe riods are defined as Forecast cells. The frequency charts display the results of the simulations, or trials, performed by Crystal Ball. Click on any chart to bring it into vi ew. The charts show the low and high endpoints of the forecasts. The View selection on the Crystal Ball toolbar can be used to specify whether you want cumulative or frequency plots shown.

a Because of the nature of the program, there is some variation in results due to random sampling when Monte Carlo or Latin Hypercube sampling is used. 8A-33. To calculate the probability that a particular value of LCC savings will occur, either type 0 in the box by the left arrow, or move the a rrow key with the cursor to 0 on the scale. The value in the Certainty box shows the like lihood that the LCC savings will occur. To calculate the certainty of payback period bei ng below a certain number of years, choose that value as the high endpoint. 4. To generate a printout repor t, select Create Report fr om the Run menu. The toolbar choice of Forecast Windows allows you to select the charts and statistics in which you are interested. For further information on Crystal Ball outputs, please refer to Understanding the Forecast Chart in the Crystal Ball manual.

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