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APPENDIX 8A. USER INSTRUCTIONS FOR LIFE-CYCLE COST AND PAYBACK 

PERIOD SPREADSHEETS

TABLE OF CONTENTS

8A-1 DEFINITIONS........................................................................................................ 8A-1

8A-2 BASIC INSTRUCTIONS....................................................................................... 8A-3

APPENDIX 8-A. 
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APPENDIX 8A. USER INSTRUCTIONS FOR LIFE-CYCLE COST AND PAYBACK 

PERIOD SPREADSHEETS

8A-1 DEFINITIONS

The interested reader can examine, reproduce, and adjust detailed results of the U.S. 

Department of Energy’s (DOE’s) life-cycle cost (LCC) and payback period (PBP) analysis for 

portable air conditioners by using Microsoft Excel spreadsheets available on DOE’s website at

http://www1.eere.energy.gov/buildings/appliance_standards/residential/dehumidifiers.html.

The latest version of the spreadsheet workbook was tested using Microsoft Excel 2010. 

The LCC workbook for residential and commercial portable air conditioners (ACs) comprises 

the following worksheets.

Summary–Residential Presents analytical results pertaining to average LCC; LCC

savings; and simple PBP for residential portable ACs. For each 

efficiency level considered, a summary table provides installed 

price; average lifetime operating cost; first-year operating cost; 

LCC; average savings; and the percentage of households that 

would incur a net cost from the efficiency level. The summary 

sheet also has an interactive component that enables users to

generate their own LCC calculation and results for an individual 

purchase by stipulating the following LCC inputs.

 Geographical location (select from 321 U.S. locations).

 Hours of operation spent in cooling and fan-only mode 

(total ≤8,760).

 Lifetime (3 to 33 years).

 Discount rate (0% to 100%). 

 Base-case efficiency level (0 through 4).

 Standards-case efficiency level (0 through 4).

 Rebound effect (0% to 100%).

 Constant cooling load (true or false).

 Price learning (true or false).

 Purchaser index (which enables the user to select a 

purchaser from the purchaser index on the RECS sample

worksheet).

Summary–Commercial Presents analytical results pertaining to average LCC; LCC 

savings; and simple PBP for commercial portable ACs. For each 

efficiency level considered, a summary table provides installed 

price; average lifetime operating cost; LCC; average savings; and 

the percentage of commercial purchases that would incur a net cost 

from the efficiency level. The summary sheet also has an 

interactive component that enables users to generate their own 
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LCC calculation and results for an individual purchase by 

stipulating the following inputs.

 Geographical location (select from 321 U.S. locations).

 Hours of operation spent in cooling mode and fan-only 

mode (total ≤8,760).

 Lifetime (3 to 33 years).

 Discount rate (0% to 100%). 

 Base-case efficiency level (0 through 4).

 Standards-case efficiency level (0 through 4).

 Rebound effect (0% to 100%).

 Constant cooling load (true or false).

 Price learning (true or false).

 Purchaser index (which enables the user to select a 

purchaser from the purchaser index on the CBECS sample

worksheet).

Residential Sample Presents the 10,000-purchaser sample used to calculate the LCC 

for the residential sector. The sample is based on households that 

reported having room or window/wall air conditioners in the RECS 

2009 survey (12,083 housing units surveyed). Identifies the 

parameters exported to the LCC and PBP analysis, including (1)

geographic location (a determinant of electricity price and sales 

tax); (2) lifetime; (3) square footage to be cooled; (4) number of 

operating hours for cooling (fan operating and stand-by mode); and 

(5) discount rate. During a simulation, DOE uses those 

characteristics to determine the analysis parameters.

Commercial Sample Presents the10,000 purchaser sample used to calculate the LCC for 

the commercial sector. The sample is based on 

commercial/institutional buildings that reported having room or 

window/wall air conditioners in the CBECS 2003 survey (5,215 

buildings surveyed). Identifies the parameters exported to the LCC 

and PBP analysis, including (1) geographic location (a determinant 

of electricity price and sales tax); (2) lifetime; (3) square footage to 

be cooled; (4) number of operating hours for cooling (fan and

stand-by mode); and (5) discount rate. During a simulation, DOE 

uses these characteristics to determine the analysis parameters.

Base-Case Efficiency Provides (1) market shares of efficiency levels in the base case; 

Distribution (2) percent of purchasers by geographic location for commercial 

and residential sectors; and (3) distribution of portable ACs by 

residential and commercial sectors. 

Equipment Prices Gives manufacturer product cost and consumer purchase price 

before sales tax (both in $2013) for every efficiency level. Includes 

the assumptions used for applying markups and sales tax. Presents 
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sales tax by RECS states/groups of states as well as by census 

division. 

Learning Curve Learning curve factors to forecast future product prices.

Lifetime Presents the average lifetime, in years, of portable ACs for both 

residential and commercial applications (10 years for both). 

Includes the Weibull parameters used for the survival function, and 

a graph of the Weibull retirement function for portable ACs.

Discount Rate Presents data used to develop average real discount rates and a 

distribution of discount rates for residential and commercial 

purchases. Rates are for the various types of debt and equity used 

to purchase products installed in homes and businesses. Appendix 

8-E gives a detailed description of DOE's development of discount 

rates.

Electricity Forecast–Res. Contains the regional price forecasts in 2013$ for electricity, which

were used in the LCC and PBP analysis. 

Electricity Forecast– Contains the regional price forecasts in 2013$ for electricity, which

Comm. were used in the LCC and PBP analysis. 

Location Lookup Contains the lookup table for matching weather station ID and 

geographic location.

8A-2 BASIC INSTRUCTIONS

Basic instructions for operating the LCC spreadsheet are provided here. 

1. After downloading the LCC spreadsheet file from DOE’s website, use Microsoft 

Excel to open it. At the bottom of the workbook, click on the tab for the sheet 

labeled Summary-Res or Summary-Comm, depending on the economic sector of 

interest (residential or commercial).

2. Use Excel’s “View/Zoom” command in the top menu bar to change the size of the 

display so that it fits your monitor.

3. Use the graphical interface in the spreadsheet to choose parameters or enter data. 

You can change the default choices for the inputs listed under "Purchaser 

parameters.” To change a default input, select the desired value from the drop-down 

choices by the input box or enter the number manually where applicable.

4. After you have selected the desired parameters, the spreadsheet will automatically 

generate updated LCC results based on the new simulation. Results are provided

under “Calculations.”