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APPENDIX 8-A. USER INSTRUCTIONS FOR THE LIFE-CYCLE COST ANALYSIS 

SPREADSHEET FOR FURNACES

TABLE OF CONTENTS

8-A.1 USER INSTRUCTIONS .......................................................................................8-A-1

8-A.2 STARTUP..............................................................................................................8-A-1

8-A.3 DESCRIPTION OF LIFE-CYCLE COST WORKSHEETS ................................8-A-1

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

SPREADSHEETS..................................................................................................8-A-3
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APPENDIX 8-A. USER INSTRUCTIONS FOR THE LIFE-CYCLE COST ANALYSIS 

SPREADSHEET FOR FURNACES

8-A.1 USER INSTRUCTIONS

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

Excel spreadsheets available on the Department of Energy’s (DOE's) central air conditioner and 

furnace rulemaking website:

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

From that page, follow the links to the notice of proposed rulemaking (NOPR) phase and then to 

Analytical Tools. 

8-A.2 STARTUP

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

(PBP) analyses for each product class. One spreadsheet exists for all three furnace product 

classes. 

To examine the spreadsheets, 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.

8-A.3 DESCRIPTION OF LIFE-CYCLE COST WORKSHEETS

For all of the furnace product classes, DOE created a single spreadsheet containing a 

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

calculation. To facilitate navigability and identify how worksheets are related, each worksheet 

contains an area on the extreme left showing variables imported to and exported from the current 

worksheet. The LCC spreadsheet contains the following worksheets: 

Summary The Summary worksheet contains a user interface to manipulate energy price 

trend and start year inputs and to run the Crystal Ball simulation. LCC and 

PBP simulation results for each efficiency level are also displayed here.

LCC&PB 

Calcs

The LCC&PB Calcs worksheet shows LCC calculation results for different 

efficiency levels for a single Residential Energy Consumption Survey (RECS) 

household.1 During a Crystal Ball simulation, the spreadsheet records the 

LCC and PBP values for every sampled household.

Rebuttable 

Payback

The Rebuttable Payback worksheet contains the total and incremental 

manufacturer costs, retail prices, the installation costs, the repair and 

maintenance costs, energy use calculations, and the simple PBP calculations 

for each efficiency level. DOE’s furnace test procedure is used to calculate 
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parameters used in energy use calculations.

Equip Price The Equip Price worksheet calculates retail price values used as inputs in the 

LCC calculations in the Summary worksheet. DOE applied baseline and 

incremental markups to calculate final retail prices. DOE calculated the 

markups differently for replacement units and new units.

Installation 

Cost

The Installation Cost worksheet provides the weighted average installation 

cost for each design option. These results are used to calculate the total 

installed prices of the design options.

Maintenance 

and Repair 

Cost

The Maintenance and Repair Cost worksheet provides the maintenance and 

repair costs for each design option. These results are used to determine

operating costs for the design options.

RECS Sample The RECS worksheet contains the RECS 2005 household data for each 

product class. During a Crystal Ball simulation, DOE uses these household 

characteristics to determine the analysis parameters.

Base Case 

AFUE

The Base Case AFUE worksheet determines the annual fuel utilization 

efficiency (AFUE) of the base case units in 2016.

AFUE 

(Existing)

The Existing AFUE worksheet includes the furnace efficiency for all years 

during the period 1966-2005.

Energy Use The Energy Use worksheet calculates annual energy use by fuel type, 

depending on product class. The annual energy use calculations for each 

design option are inputs to the LCC&PB Calcs worksheet to calculate the 

annual operating cost of the LCC.

Energy Price The Energy Price worksheet shows the estimated monthly natural gas, 

electricity, and oil prices.

Energy Price 

Trends

The Energy Price Trends worksheet shows the future price trends of the 

different heating fuels. DOE used energy price data and forecasts from the

Energy Information Administration’s (EIA's) Annual Energy Outlook 2010

for the period until 2035 and extrapolated beyond 2035.

2

Discount Rate The Discount Rate worksheet contains the distributions of discount rates for 

replacement and new units.

Lifetime The Lifetime worksheet contains the distribution of lifetimes for equipment of 

that product class.
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Labor Costs The Labor Costs worksheet contains the labor cost factors by region.

Census 

Population 

Data

The Census Population Data worksheet contains the Census estimated 

housing units by State. 

Models Data The Models Data worksheet includes characteristics of the furnace products 

used in the analysis. 

Energy Use 

Adjustment 

Factors 

The Energy Use Adjustment Factors worksheet contains the energy use 

adjustment factors by region according to heating and cooling degree day 

data. 

Weather Data The Weather Data worksheet contains heating degree days, cooling degree 

days, heating and cooling outdoor design temperature, and annual mean 

temperature by weather station.

Shipments The Shipments worksheet contains historical furnace shipments by State by 

product class. 

NIA Inputs The NIA Inputs worksheet contains intermediate inputs used for other DOE 

analyses.

8-A.4 BASIC INSTRUCTIONS FOR OPERATING THE LIFE-CYCLE 

COST SPREADSHEETS 

Basic instructions for operating the LCC spreadsheet are as follows:

1. Once the LCC spreadsheet has been downloaded, open the file using Excel. Click 

“Enable Macro” when prompted and then click on the tab for the Summary worksheet.

2. Use Excel's View/Zoom commands at the top menu bar to change the size of the display 

to fit your monitor.

3. The user can change the parameters listed under USER OPTIONS on the Summary

worksheet. There are three drop-down boxes and one command button. The default 

parameters are:

a. Energy Price Trend: Defaults to “AEO 2010 - Reference Case.” To change the 

input, use the drop-down menu and select the desired trend (Reference, Low, or 

High).

b. Start Year: Defaults to “2016.” To change the value, use the drop-down menu and 

select the desired year.
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c. # of Trials: Defaults to “10,000.” To change the value, use the drop-down menu

and select the desired number of trials (1,000, 2,000, 3,000, 5,000, or 10,000).

d. Subgroup: Defaults to “National.” To change the sample used for LCC and PBP 

calculations, use the drop-down menu and select the desired subgroup from the 

available samples (National, Low-Income, Senior-Only, Multi-Family).

4. To run the Crystal Ball simulation, click the “run” button (you must re-run after changing 

any parameters). The spreadsheet will then be minimized. You can monitor the progress 

of the simulation by watching the count of iterations at the left bottom corner. When the 

simulation is finished, the worksheet named Summary will reappear with the results.
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REFERENCES

1. U.S. Department of Energy - Energy Information Administration, Residential Energy 

Consumption Survey: 2005 Public Use Data Files, 2005.

<http://www.eia.doe.gov/emeu/recs/recspubuse05/pubuse05.html>

2. Energy Information Administration, Annual Energy Outlook 2010 with Projections to 

2035, 2010. Washington, DC. Report No. DOE/EIA-0383(2010). 

<http://www.eia.doe.gov/oiaf/aeo/>