6A-i

APPENDIX 6A. USER INSTRUCTIONS FOR THE LIFE-CYCLE COST ANALYSIS 

SPREADSHEET FOR COMPUTER ROOM AIR CONDITIONERS

TABLE OF CONTENTS

6A.1 USER INSTRUCTIONS .............................................................................................. 6A-1

6A.2 STARTUP..................................................................................................................... 6A-1

6A.3 DESCRIPTION OF LIFE-CYCLE COST WORKSHEETS ....................................... 6A-1

6A.4 BASIC INSTRUCTIONS FOR OPERATING THE LIFE-CYCLE COST 

SPREADSHEET........................................................................................................... 6A-3

LIST OF TABLES

Table 6A.3.1 Key Worksheets in LCC Workbook................................................................... 6A-2
6A-1

APPENDIX 6A. USER INSTRUCTIONS FOR THE LIFE-CYCLE COST ANALYSIS 

SPREADSHEET FOR COMPUTER ROOM AIR CONDITIONERS

6A.1 USER INSTRUCTIONS

The results obtained in this analysis can be examined and reproduced using the Microsoft 

Excel spreadsheets available on the U.S. Department of Energy’s (DOE’s) ASHRAE Equipment

rulemaking website: 

www1.eere.energy.gov/buildings/appliance_standards/commercial/ashrae_products_docs_meeti

ng.html. From that page, follow the links to the final rule and then to Analytical Tools. 

6A.2 STARTUP

DOE’s spreadsheet enables users to perform life-cycle cost (LCC) and payback period 

(PBP) analyses for each equipment class. One spreadsheet exists for all computer room air 

conditioning (CRAC) equipment classes. 

To examine the spreadsheet, DOE assumes that the user has access to a personal 

computer with a hardware configuration capable of running Windows XP or later. All LCC 

spreadsheets require Microsoft Excel 2003 or later installed under the Windows operating 

system. Because certain variables inside the spreadsheets are defined as distributions, a copy of 

Crystal Ball (a commercially available add-on program) is required to view them.

6A.3 DESCRIPTION OF LIFE-CYCLE COST WORKSHEETS

For all of the CRAC equipment classes, DOE created a single spreadsheet containing a 

collection of worksheets. Each worksheet represents a conceptual component within the LCC 

calculation. Table 6A.3.1 lists the worksheets contained in the LCC spreadsheet.
6A-2

Table 6A.3.1 Key Worksheets in LCC Workbook

Worksheet Description

Labels This is used as a go-between for user inputs and the rest of the 

worksheets. Do not modify this sheet.

LCC Summary Contains the input selections and a summary table of energy use,

installation and operating costs, LCCs, and PBP.

Crystal Ball Contains outputs for each equipment class from the Crystal Ball/Monte 

Carlo analysis. 

NIA Output Not used. This sheet is hidden.

Econ Trends Contains electricity price forecasts, organized for export to downstream 

models. Also contains price learning data inputs.

Markups Contains data used to derive industry baseline and incremental markups.

Engineering Contains the manufacturer price data for units at each efficiency level. 

Also contains cooling capacities, energy usage, repair and maintenance 

costs, and other equipment-specific data. 

Discounted Costs Contains discounted annual and cumulative discounted operating costs. 

Discount Rate Contains all data used to calculate discount rates for each building type 

and an aggregate discount rate for the United States.

Electricity Prices Contains 2011population-weighted electricity prices by state, Annual 

Energy Outlook 2011 electricity price projections, and electricity price 

ratios derived for the various building types using the 2003 Commercial 

Building Energy Consumption data.

Installation Costs Contains multipliers to vary the installation cost by state. Derived from 

data published by RS Means, a division of Reed Construction Data.

Sales Tax Contains data on sales tax rates by state and population data by state.

EnergyConsumption Contains data on unit energy consumption for each CRAC equipment 

class for all estates at each efficiency level.

Population Contains 2011 Census Bureau estimates of population by state.

Maintenance and Repair 

Costs

Contains inputs for different schedules of maintenance and repair costs 

and summarizes the data in an annualized format.

Economizer Contains selected market data to allocate the use of economizers to 

specific market segments

TSD Tables Contains selected summary input and output information.

CB Results (multiple dates) Contains output data from selected Crystal Ball runs of the model.

Results for NIA (multiple 

dates)

Contains output data formatted for use by the national impact analysis 

(NIA) model.
6A-3

6A.4 BASIC INSTRUCTIONS FOR OPERATING THE LIFE-CYCLE COST 

SPREADSHEET

Basic instructions for operating the LCC spreadsheet are as follows.

Step Description

1. Once you have downloaded the LCC file from the DOE Appliances and Commercial 

Equipment Standards website, open the file using Excel. Select Yes when asked if you 

want to enable macros. At the bottom of the Excel window, click the tab for the LCC 

Summary sheet. Note that if you plan to run the Monte Carlo routine, you will need to 

have Crystal Ball loaded as an add-in and activated.

2. Use Excel’s View/Zoom commands at the top menu bar to size the display to your 

monitor.

3. You can interact with the spreadsheet by clicking choices or entering data using the 

graphical interface on the LCC Summary tab. Select choices from the various 

dropdown input boxes throughout the LCC Summary tab.

4. From the user-defined input options, select from the buttons and boxes for the 

following: (1) assumed baseline level; (2) equipment class; (3) analysis year (year of

purchase); (4) economic growth case; (5) year to discount costs to; (6) standard 

efficiency level; (7) building type; (8) state or region to analyze; (9) conservation 

program to model; (10) installation cost escalation; (11) repair cost escalation; 

(12) analysis type; (13) price learning toggle; and (14) discounting toggle. You can start 

a complete Crystal Ball simulation by clicking the Monte Carlo button. All input

options, with the exception of some conservation program inputs, are either dropdown 

option boxes or toggle boxes (checked boxes make the statement true).

4A. Equipment classes are defined as particular combinations of equipment families,

cooling method, and size categories. Currently there are 15 equipment classes. They can 

be selected individually in sensitivity mode and all classes can be run in Monte Carlo 

mode. The dropdown menu provides the available equipment class selections.

4B. The model is set up to run up to eight possible efficiency levels, including the baseline 

efficiency level. However, all equipment classes are currently set to run the baseline 

and four additional representative levels. If an equipment class contains fewer than 

eight levels, the calculated output cells of the extra levels will have no values on the 

LCC Summary tab.

5. This spreadsheet gives the user two types of calculation methods: Sensitivity and Monte 

Carlo mode, using Crystal Ball.

5A. If base and sensitivity analysis is chosen, then all calculations are performed for a set of 

single input values, usually an average. The new results are shown on the Summary tab 

as soon as the input values are changed through a dropdown menu or toggle box.
6A-4

5B. Alternatively, if the Monte Carlo option is chosen or if the button is clicked, the 

spreadsheet generates a set of results from calculations for each equipment class. For a 

number of inputs, the Crystal Ball software has custom distributions that it uses to set 

the level of the input. The model runs each of the studied classes in turn, performing 

5,000 model runs for each. At the end of each equipment class run, the model records to 

the Crystal Ball tab a large number of outputs that you can then work with for further 

analyses. The Monte Carlo button executes a macro written in Visual Basic for 

applications to loop through all equipment classes and selected efficiency levels. The 

Monte Carlo analysis usually takes 3 to 4 hours to complete for all 15 equipment 

classes.