10-i

CHAPTER 10: NATIONAL IMPACT ANALYSIS 

TABLE OF CONTENTS 

10.1 INTRODUCTION ......................................................................................................... 10-1

10.2 FORECASTED EFFICIENCIES FOR BASE AND STANDARDS CASES .............. 10-2

10.3 NATIONAL ENERGY SAVINGS ............................................................................... 10-5

10.3.1 Primary Energy Savings ................................................................................................ 10-5

10.3.2 Full-Fuel-Cycle Energy Savings .................................................................................... 10-6

10.3.3 Inputs to National Energy Savings ................................................................................ 10-7

10.3.3.1 Shipments ..................................................................................................... 10-7

10.3.3.2 Product Stock ............................................................................................... 10-8

10.3.3.3 Annual Energy Consumption per Unit ........................................................ 10-8

10.3.3.4 National Annual Energy Consumption ........................................................ 10-8

10.3.3.5 Site-to-Power Plant Conversion Factors ...................................................... 10-8

10.3.3.1 Primary Energy to Full-Fuel-Cycle Multipliers ........................................... 10-9

10.3.3.2 Rebound Rate Factor .................................................................................... 10-9

10.4 NET PRESENT VALUE ............................................................................................. 10-10

10.4.1 Definition ..................................................................................................................... 10-10

10.4.2 Inputs to Net Present Value ......................................................................................... 10-11

10.4.2.1 Total Installed Cost per Unit ...................................................................... 10-12

10.4.2.2 Annual Operating Cost Savings per Unit................................................... 10-13

10.4.2.3 Total Annual Increases in Installed Cost ................................................... 10-13

10.4.2.4 Total Annual Savings in Operating Cost ................................................... 10-13

10.4.2.5 Discount Factors ........................................................................................ 10-14

10.4.2.6 Present Value of Costs ............................................................................... 10-14

10.4.2.7 Present Value of Savings ........................................................................... 10-14

10.5 RESULTS OF CALCULATIONS .............................................................................. 10-15

10.5.1 Summary of Inputs ....................................................................................................... 10-15

10.5.2 Results of National Energy Savings Calculations ....................................................... 10-16

10.5.3 Annual Costs and Savings ........................................................................................... 10-16

10.5.4 Results of Net Present Value Calculations .................................................................. 10-17

LIST OF TABLES 

Table 10.1.1 Candidate Standard Levels for Dehumidifiers—IEF* (Units: L/kWh†) ........... 10-2

Table 10.2.1 Portable Dehumidifiers ≤20.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 ........................................................................ 10-3

Table 10.2.2 Portable Dehumidifiers 20.01–30.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 ........................................................................ 10-3

Table 10.2.3 Portable Dehumidifiers 30.01–35.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 ........................................................................ 10-4
10-ii

Table 10.2.4 Portable Dehumidifiers 35.01–45.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 ........................................................................ 10-4

Table 10.2.5 Portable Dehumidifiers >45.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 ........................................................................ 10-4

Table 10.2.6 Whole-Home Dehumidifiers ≤8.0 ft3 Case Volume: Base- and StandardsCase Efficiency Distributions in 2019 ............................................................... 10-5

Table 10.2.7 Whole-Home Dehumidifiers >8.0 ft3

 Case Volume: Base- and StandardsCase Efficiency Distributions in 2019 ............................................................... 10-5

Table 10.5.2 Cumulative National Energy Savings (Unit: Quads) ....................................... 10-16

Table 10.5.3 Full-Fuel-Cycle National Energy Savings (Unit: Quads) ................................ 10-16

Table 10.2.8 Cumulative NPV Results Based on 3-Percent Discount Rate (Billion, 

2012$) .............................................................................................................. 10-18

Table 10.2.9 Cumulative NPV Results Based on 7-Percent Discount Rate (Billion, 

2012$) .............................................................................................................. 10-18

FIGURE 

Figure 10-1 Site-to-Power Plant Energy Conversion Factors for Dehumidifiers .................. 10-9

Figure 10-2 Non-Discounted Annual Installed Cost Increases and Annual Operating 

Cost Savings for Dehumidifiers, CSL 3 .......................................................... 10-17
10-1

CHAPTER 10. NATIONAL IMPACT ANALYSIS

10.1 INTRODUCTION 

 This chapter of the preliminary technical support document (TSD) describes the method 

the U.S. Department of Energy (DOE) used to estimate the effects on national energy 

consumption of candidate standard levels (CSLs) for dehumidifiers. DOE evaluated the 

following effects: (1) national energy savings (NES) attributable to each potential standard; (2) 

the monetary value of energy savings to consumers of dehumidifiers; (3) increased total installed 

cost of the products because of standards; and (4) the net present value (NPV) of energy savings 

(i.e., the difference between the operational savings and increased total installed costs). 

 DOE determined both the NES and NPV for all the CSLs considered for the product 

classes of both portable and whole-home dehumidifiers. It performed all calculations using a 

Microsoft Excel spreadsheet model, which is accessible on the Internet 

(http://www1.eere.energy.gov/buildings/appliance_standards/residential/dishwashers.html). The 

spreadsheets, which implement the National Impact Analysis (NIA) model, combine the 

calculations for determining the NES and NPV with input from the shipments model (chapter 9 

of the preliminary TSD). Details and instructions for using the NIA model are provided in 

appendix 10A of this preliminary TSD.

 Chapter 9 of this preliminary TSD provides a detailed description of the shipments model 

that DOE used to forecast future purchases of dehumidifiers. Chapter 9 includes detailed 

descriptions of consumers’ sensitivities to total installed cost and operating cost, and how DOE 

captured those sensitivities within the model. 

 To estimate the national impacts of new standards for all the product classes considered 

in this rulemaking, DOE allocated the product cost and annual energy consumption of each 

representative product class to all product classes within its category. 

DOE analyzed the benefits and burdens of four CSLs for five product classes of portable 

dehumidifiers and two product classes of whole-home dehumidifiers. The CSLs were developed 

using combinations of efficiency levels for all seven product classes that DOE analyzed. Table 

Error! Reference source not found. presents the CSLs and the corresponding efficiency levels 

for dehumidifiers. CSL 4 represents the maximum technologically feasible (“max-tech”)

improvement in energy efficiency for dehumidifiers. CSLs 2 and 3 represent intermediate 

efficiency levels between CSLs 1 and 4. CSL 1 represents the first efficiency level considered 

that exceeds baseline efficiency. 
10-2

Table 10.1.1 Candidate Standard Levels for Dehumidifiers—IEF* (Units: L/kWh†) 

CSL ≤20.00

pints/day

20.01-

30.00

pints/day

30.01-

35.00

pints/day

35.01-

45.00

pints/day

>45.00 

pints/day

≤8.0 ft3

Case 

Volume

(WholeHome)

>8.0 ft3

Case 

Volume 

(WholeHome)

Baseline 0.77 0.80 0.94 1.00 2.07 1.10 1.68

CSL 1 1.10 1.10 1.20 1.30 2.40 1.40 1.90

CSL 2 1.20 1.20 1.40 1.40 2.80 1.40 2.80

CSL 3 1.30 1.30 1.60 1.60 2.80 1.40 2.80

CSL 4 1.42 1.52 1.75 1.75 3.52 1.59 3.41

 * IEF = Integrated energy factor, which includes energy consumed in standby, off, dehumidification, and fan-only 

modes. 

 

†

 L/kWh = Liters (of moisture removed) per kilowatt-hour (of energy consumed). 

10.2 FORECASTED EFFICIENCIES FOR BASE AND STANDARDS CASES 

 This section describes the method DOE used to forecast the energy efficiencies of 

dehumidifiers for the base case and for each of the candidate standards cases. It provides 

efficiency distributions for all product classes of both portable and whole-home dehumidifiers.

 A key factor in estimating NES and NPV is the trend in energy efficiency forecasted for 

the base case (without new standards) and each of the standards cases. In calculating the NES, 

per-unit annual energy consumption is a direct function of product efficiency. For the NPV, two 

inputs, the per-unit total installed cost and the per-unit annual operating cost, depend on 

efficiency. The first input, the per-unit total installed cost, is a direct function of efficiency. 

Because it is a function of annual energy use, the per-unit annual operating cost depends 

indirectly on product efficiency. 

 Using the shipment-weighted efficiency of dehumidifiers for 2013 as a starting point, 

DOE projected efficiencies for the base case based on assumptions regarding future 

improvements in efficiency and assumed an annual growth rate of 0.25 percent between 2019

and 2048. 

DOE assumed a “roll-up” scenario to establish the shipment-weighted efficiency for the 

year that standards are assumed to become effective (2019). DOE assumed that product 

efficiencies in the base case that did not meet the standard under consideration would “roll up” to 

meet the new standard level. For its projected efficiencies of CSLs, in addition to a “roll-up” 

scenario, DOE developed a shift scenario. In the shift scenario DOE applies an annual growth 

rate in average energy efficiency to the shipment-weighted integrated energy factors (SWIEF), as 

it is done in the base case. To develop standards case forecasted SWIEFs, DOE developed 

growth trends for each candidate standard level that maintained the same per-unit average total 

installed cost difference for the year 2019 between the base case and each standards case over the 

entire forecast period (2019–2048). DOE’s approach for developing standards case SWIEFs in 
10-3

this manner assumes that the rate of adoption of more efficient products under the standards case 

can occur only at a rate which ensures that the average total installed cost difference between the 

standards case and base case over the entire forecast period is held constant. Because the total 

installed cost versus efficiency relationship for each product class demonstrates an increasing 

cost rate for more efficient products, the SWIEF growth rate for each standards case is lower 

than the SWIEF growth rate for the base case.

Chapter 10. through Table 10.2.7 show the base-case and CSL product efficiency 

distributions in 2019, based on the integrated energy factor (IEF) for each of the seven product 

classes that DOE is considering. The CSLs are composed of efficiency levels analyzed in the 

life-cycle cost and payback period analysis (chapter 8 of the preliminary TSD). Also included in 

the tables are the shipment-weighted integrated energy factors (SWIEFs) and shipment-weighted 

annual energy use (SWAEU) associated with the base case and each CSL.

Table 10.2.1 Portable Dehumidifiers ≤20.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 

EL CSL

IEF

Market Shares (%)

Base 

Case

Candidate Standard Level

(L/kWh) 1 2 3 4

Baseline - 0.77 62 0 0 0 0

1 1 1.10 6 68 0 0 0

2 2 1.20 0 0 68 0 0

3 3 1.30 29 29 29 97 0

4 4 1.42 3 3 3 3 100

SWIEF (L/kWh) 0.96 1.17 1.24 1.30 1.42

SWAEU (kWh/yr) 517 405 381 360 331

Table 10.2.2 Portable Dehumidifiers 20.01–30.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 

EL CSL IEF

(L/kWh)

Market Share (%)

Base 

Case

Candidate Standard Level

1 2 3 4

Baseline - 0.80 0 0 0 0 0

1 1 1.10 47 47 0 0 0

2 2 1.20 21 21 68 0 0

3 3 1.30 27 27 27 94 0

4 4 1.52 6 6 6 6 100

SWIEF (L/kWh) 1.20 1.20 1.24 1.31 1.52

SWAEU (kWh/yr) 550 550 527 499 431
10-4

Table 10.2.3 Portable Dehumidifiers 30.01–35.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 

EL CSL IEF

(L/kWh)

Market Share (%)

Base 

Case

Candidate Standard Level

1 2 3 4

Baseline - 0.94 0 0 0 0 0

1 1 1.20 49 49 0 0 0

2 2 1.40 48 48 97 0 0

3 3 1.60 0 0 0 97 0

4 4 1.75 3 3 3 3 100

SWIEF (L/kWh) 1.31 1.31 1.41 1.60 1.75

SWAEU (kWh/yr) 653 653 603 530 486

Table 10.2.4 Portable Dehumidifiers 35.01–45.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 

EL CSL IEF

(L/kWh)

Market Share (%)

Base 

Case

Candidate l Standard Level

1 2 3 4

Baseline - 1.00 0 0 0 0 0

1 1 1.30 34 34 0 0 0

2 2 1.40 61 61 95 0 0

3 3 1.60 1 1 1 96 0

4 4 1.75 4 4 4 4 100

SWIEF (L/kWh) 1.38 1.38 1.42 1.61 1.75

SWAEU (kWh/yr) 758 758 739 651 597

Table 10.2.5 Portable Dehumidifiers >45.00 Pints/Day: Base- and Standards-Case 

Efficiency Distributions in 2019 

EL CSL IEF

(L/kWh)

Market Share (%)

Base 

Case

Candidate Standard Level

1 2 3 4

Baseline - 2.07 39 0 0 0 0

1 1 2.40 29 68 0 0 0

2 2, 3 2.80 16 16 84 84 0

3 4 3.52 16 16 16 16 100

SWIEF (L/kWh) 2.52 2.64 2.92 2.92 3.52

SWAEU (kWh/yr) 933 958 971 971 1,043
10-5

Table 10.2.6 Whole-Home Dehumidifiers ≤8.0 ft3 Case Volume: Base- and StandardsCase Efficiency Distributions in 2019 

EL CSL IEF

(L/kWh)

Market Share (%)

Base Case

Candidate Standard Level

1 2 3 4

Baseline - 1.10 25 0 0 0 0

1 1, 2, 3 1.40 19 44 44 44 0

2 4 1.59 56 56 56 56 100

SWIEF (L/kWh) 1.43 1.51 1.51 1.51 1.59

SWAEU (kWh/yr) 1,131 1,137 1,137 1,137 1,185

Table 10.2.7 Whole-Home Dehumidifiers >8.0 ft3 Case Volume: Base- and StandardsCase Efficiency Distributions in 2019 

EL CSL IEF

(L/kWh)

Market Share (%)

Base Case

Candidate Standard Level

1 2 3 4

Baseline - 1.68 22 0 0 0 0

1 1 1.90 46 68 0 0 0

2 2, 3 2.80 16 16 84 84 0

3 4 3.41 16 16 16 16 100

SWIEF (L/kWh) 2.24 2.29 2.90 2.90 3.41

SWAEU (kWh/yr) 1,472 1,475 1,511 1,511 1,621

Based on the assumption of a 0.25 percent growth rate in the efficiencies for the base 

case, DOE maintained the SWIEFs shown in Chapter 10. through Table 10.2.7 throughout the 

projection period, from 2019 to 2048.

10.3 NATIONAL ENERGY SAVINGS 

 DOE calculated the national energy savings (NES) associated with the difference 

between the base case and each of the potential standards cases for dehumidifiers. DOE 

calculated cumulative energy savings from 2019 to 2048. 

10.3.1 Primary Energy Savings 

 DOE calculated annual NES as the difference between two projections: a base case 

(without new standards) and a standards case (with new standards). Positive values of NES 

represent energy savings (i.e., national annual energy consumption under a standard is less than 

under the base case). 
10-6

 ( ) 

 Cumulative energy savings are the sum of the national annual energy savings throughout 

the forecast period, which starts in the compliance year (2019) and ends after 30 years (2048).

The calculation is represented by the following equation. 

NEScumulative  NESy

 DOE calculated the national annual energy consumption by multiplying the number or 

stock of each product class (by vintage) by its unit energy consumption (also by vintage). The 

calculation of the national annual energy consumption is performed using the following 

equation. 

AEC  STOCKV UECV

DOE defined the quantities for the above expressions as follows. 

AEC = National annual energy consumption each year in quadrillion British thermal units 

(quads) summed over vintages of the product stock, STOCKV.

NESy = National annual energy savings (quads). 

STOCKV = Stock of product (millions of units) of vintage V surviving in the year for which 

DOE calculated annual energy consumption.

UECV = Annual energy consumption per product in either kilowatt-hours (kWh) or million 

Btus (MMBtu) (electricity and gas consumption are converted from site energy to 

source energy (quads) by applying a time-dependent conversion factor). 

V = Year in which the product was purchased as a new unit.

y = Year in the forecast. 

 = Rebound rate factor = 1- rebound rate. 

 The stock of a product depends on annual shipments and the lifetime of the product. As 

described in chapter 9 of the preliminary TSD, DOE projected dehumidifier shipments under the 

base and standards cases. To avoid including savings attributable to shipments displaced because 

of standards (consumers deciding not to buy higher-priced products), DOE used the projected 

standards-case shipments and, in turn, the standards-case stock, to calculate the AEC for the base 

case.

10.3.2 Full-Fuel-Cycle Energy Savings 

 DOE has historically presented the NES computed based on the primary energy savings 

at the power plant, as described in the previous section. Per DOE’s 2011 Statement of Policy for 
10-7

Adopting Full Fuel Cycle Analyses, DOE now uses full-fuel-cycle (hereafter, FFC) measures of 

energy use and emissions in its energy conservation standards analyses.1In addition to the 

primary energy used at the power plant to supply electricity to the site of use and account for 

transmission and distribution losses, the FFC analysis also accounts for energy consumed upstream of the power plant in extracting, processing, and transporting or distributing the primary 

fuels to the power plant, as described in appendix 10B. 

 As shown in the equation beow, the FFC national energy savings are obtained by 

multiplying the primary energy savings (Error! Reference source not found.) by the FFC 

multiplier computed for the same year, .

 ( ) 

Where: 

 =the FFC multiplier in year , and 

All other variables were defined in Error! Reference source not found.

The cumulative FFC energy savings is calculated by summing the annual FFC energy saving 

from 2019-2097.

 ∑ 

 

10.3.3 Inputs to National Energy Savings 

 The inputs to the calculation of NES are: 

 shipments,

 product stock (STOCKV),

 annual energy consumption per unit (UEC),

 national annual energy consumption (AEC),

 site-to-source conversion factor (src_conv) , 

 primary energy to full fuel cycle multipliers (μ), and 

 rebound rate factor (RF). 

10.3.3.1 Shipments 

 DOE projected shipments for the base case and all standards cases. Several factors, 

including total installed cost (purchase price plus installation costs), operating cost, and product 
10-8

lifetime, all affect projected shipments. Chapter 9 of the preliminary TSD, Shipments Analysis,

details the method DOE used to calculate and generate the shipments projections for 

dehumidifiers. 

10.3.3.2 Product Stock 

 The product stock in a given year is the number of products shipped from earlier years 

that survive in that year. The NIA model tracks the number of units shipped each year. DOE

assumes that products have an increasing probability of retiring as they age. The probability of 

survival as a function of years since purchase is the survival function. Chapter 9 of the 

preliminary TSD provides additional details on the survival functions that DOE used for portable 

and whole-home dehumidifiers. 

10.3.3.3 Annual Energy Consumption per Unit 

 DOE used the shipment-weighted annual energy use (SWAEU) defined in section 10.2 

for the base case and standards cases, along with the data on AEC presented in chapters 7 and 8 

of the preliminary TSD, to estimate the shipment-weighted average annual per-unit energy 

consumption under base and standards cases. 

10.3.3.4 National Annual Energy Consumption 

 The national annual energy consumption is the product of the annual energy consumption 

per unit and the number of units of each vintage (V). The calculation of AEC accounts for 

differences in unit energy consumption from year to year. DOE used the equation below (as 

presented in section 10.3.1) to calculate annual energy consumption. 

 

AEC STOCKV UECV

To determine national annual energy consumption, DOE calculated the annual energy 

consumption at the site and then applied a conversion factor to calculate primary energy 

consumption, as described below. 

10.3.3.5 Site-to-Power Plant Conversion Factors 

 In determining AEC, DOE initially calculated the annual energy consumption at the site 

(for electricity, the energy in kWh consumed at the household or establishment). It then used site 

energy consumption to calculate primary (source) energy consumption by applying a conversion 

factor to account for losses associated with the generation, transmission, and distribution of 

electricity. The site-to-source conversion factor is a multiplicative factor used to convert site 

energy consumption into primary, or source, energy consumption expressed in quads (quadrillion 

Btus). DOE used annual site-to-power plant conversion factors based on the version of the 
10-9

National Energy Modeling System (NEMS)a

that corresponds to EIA’s Annual Energy Outlook 

2013 (AEO 2013).2

The factors are marginal values, which represent the response of the power 

supply system to an incremental decrease in consumption. For electricity, the conversion factors 

change over time in response to projected changes in generation sources (i.e., the types of power 

plants projected to provide electricity to the Nation). Figure 10-1 shows the site-to-power plant 

conversion factors from 2019 to 2048. The value reported in AEO 2013 for 2040 (the last year 

covered) was extrapolated through the end of the projection period. 

Figure 10-1 Site-to-Power Plant Energy Conversion Factors for Dehumidifiers 

10.3.3.1 Primary Energy to Full-Fuel-Cycle Multipliers 

 For this preliminary analysis, DOE calculated FFC energy savings using a methodology 

described in appendix 10B. As discussed previously, the FFC energy savings are obtained by 

multiplying the primary energy savings at the power plant by the FFC multiplier. The estimated 

FFC multiplier (μ) is essentially constant, ranging between 1.040 and 1.041 from 2019 to 2077. 

10.3.3.2 Rebound Rate Factor 

 A rebound effect accounts for increased usage of an appliance by consumers after the 

implementation of a standard, reducing the energy savings attributed to a standard. DOE 

 

a

 For more information on NEMS, refer to the U.S. Department of Energy, Energy Information Administration 

documentation. A useful summary is National Energy Modeling System: An Overview 2000. DOE/EIA0581(2000), March 2000. EIA approves use of the name NEMS only to describe an official version of the model 

without any modification to code or data. Because this analysis entails some minor code modifications, and the 

model is run under policy scenarios that are variations on EIA assumptions, DOE refers to the model as NEMS-BT 

(BT is DOE’s Building Technologies Program, under whose aegis this work was performed). NEMS-BT 

previously was called NEMS-BRS. 

7.80

7.90

8.00

8.10

8.20

8.30

8.40

8.50

8.60

8.70

MMBtu/MWh

Year
10-10

generally accounts for the direct rebound effect in its estimates of the NES. As discussed in 

chapter 2 of this TSD, for this preliminary analysis, DOE used a rebound rate of zero. DOE 

welcomes data on rebound effects in dehumidifiers. 

10.4 NET PRESENT VALUE 

 DOE calculated the net present value (NPV) of the increased product price and reduced 

operating cost associated with the difference between the base case and each potential standards 

case for the dehumidifier product classes. 

10.4.1 Definition 

 The NPV is the value in the present of a time-series of costs and savings. The NPV is 

described by the equation: 

NPV PVCPVS

_



Where: 

PVS = present value of operating cost savings, and 

PVC = present value of increased total installed costs (including purchase price and 

installation costs). 

 DOE determined the PVS and PVC according to the following expressions.

PVS ∑OCS  DFyy

PVC ∑TIC  DFyy

Where: 

OCS = total annual savings in operating costs each year summed over vintages of the 

product stock, STOCKV; 

DF = discount factor in each year; 

TIC = total annual increases in installed cost each year summed over vintages of the 

product stock, STOCKV; and 

y = year in the forecast. 

 DOE calculated the total annual consumer savings in operating cost by multiplying the 

number or stock of a given product class (by vintage) by its per-unit operating cost savings (also 

by vintage). DOE calculated the total annual increases in consumer product price by multiplying 

the number or shipments of the given product class (by vintage) by its per-unit increase in 
10-11

consumer product cost (also by vintage). The calculation of total annual operating cost savings 

and total annual product price increases are represented by the following equations. 

y ∑ V UOCSV OCS  STOCK 

y ∑ y UTICy TIC  SHIP 

Where: 

STOCKV = stock of products of vintage V that survive in the year for which DOE calculated 

annual energy consumption, 

UOCSV = annual operating cost savings per unit of vintage V,

V = year in which the product was purchased as a new unit; 

SHIPy = shipments of products in year y; and 

UTICy = annual per-unit increase in installed product price in year y. 

 DOE determined the total increased product price for each year from 2019 to 2048. DOE

determined the present value of operating cost savings for each year from 2019 to the year when 

all units purchased in 2048 will have been retired. DOE calculated costs and savings as the 

difference between a standards case and a base case without new standards. 

 DOE developed a discount factor from the national discount rate and the number of years 

between the “present” (year to which the sum is being discounted) and the year in which the 

costs and savings occur. The NPV is the sum over time of the discounted net savings. 

10.4.2 Inputs to Net Present Value 

 The inputs to the calculation of NPV are: 

 total installed cost per unit, 

 annual operating cost savings per unit, 

 total annual increases in product price,

 total annual savings in operating cost,

 discount factor, 

 present value of costs, and

 present value of savings. 

 The increase in the total annual installed cost is equal to the annual change in the per-unit 

total installed cost (difference between base and standards case) multiplied by the shipments 

forecasted in the standards case. 

 The total annual operating cost savings are equal to the change in annual operating cost 

(difference between base and standards case) per unit multiplied by the shipments forecasted in 
10-12

the standards case. As noted, DOE did not calculate operating cost savings using base-case 

shipments. The annual operating cost includes energy costs. 

10.4.2.1 Total Installed Cost per Unit 

 The average annual product cost depends directly on efficiency. DOE therefore used the 

efficiency distributions presented in Chapter 10. through Table 10.2.7, along with the product 

price at various efficiency levels (presented in chapter 8 of the preliminary TSD), to estimate the 

shipment-weighted average annual product cost under the base and standards cases. Table 10.4.1 

shows the shipment-weighted average consumer product price based on the SWIEFs that 

correspond to the base case and each standards case for each product class in 2019. 

Table 10.4.1 Shipment-Weighted Average Per-Unit Total Installed Costs for Base and 

Standards Cases

Product Class SWIEF & 

Total Installed Cost

Base 

Case

Candidate Standard Level

1 2 3 4

≤20 pints/day SWIEF (L/kWh) 0.96 1.17 1.24 1.30 1.42

Total installed cost (2012$) $221 $221 $223 $227 $232 

20.01–30.00

pints/day

SWIEF (L/kWh) 1.20 1.20 1.24 1.31 1.52

Total installed cost (2012$) $234 $234 $236 $238 $249 

30.01–35.00

pints/day

SWIEF (L/kWh) 1.31 1.31 1.41 1.60 1.75

Total installed cost (2012$) $263 $263 $266 $275 $283 

35.01–45.00

pints/day

SWIEF (L/kWh) 1.38 1.38 1.42 1.61 1.75

Total installed cost (2012$) $284 $284 $285 $294 $300 

>45.00 pints/day SWIEF (L/kWh) 2.52 2.64 2.92 2.92 3.52

Total installed cost (2012$) $933 $958 $971 $971 $1,043 

≤8.0 ft3case volume 

(whole-home)

SWIEF (L/kWh) 1.43 1.51 1.51 1.51 1.59

Total installed cost (2012$) $1,693 $1,699 $1,699 $1,699 $1,747 

>8.0ft3case volume 

(whole-home)

SWIEF (L/kWh) 2.24 2.29 2.90 2.90 3.41

Total installed cost (2012$) $2,034 $2,037 $2,073 $2,073 $2,183 

As noted in section 10.2, DOE assumed that projected efficiencies in the base case and 

CSLs remain frozen at the efficiency levels of 2019. Because the per-unit total installed costs are 

a function of efficiency, DOE held the values constant over the projection period (2019–2048).

 To evaluate the effect of uncertainty regarding price trends, DOE examined the effect of 

various product price forecasts on the consumer NPV for the considered CSLs for residential 

dehumidifiers. In addition to the default price trend, DOE considered separate product price 

sensitivity cases for portable dehumidifiers and whole-home dehumidifiers. For portable 

dehumidifiers, DOE considered a case for a low price decline based on estimating an experience 
10-13

curve using Producer Price Index (PPI) data for “small electric household appliances” from 1983 

to 2012. A case for high price decline was based on the price forecast of the “furniture and 

appliances” series from AEO 2013. For whole-home dehumidifiers, a case for a low price decline 

was based on an exponential fit to the PPI from 1978 to 2012 for “air-conditioning, refrigeration, 

and forced air heating equipment.” The high price decline was based on the price forecast of the 

“furniture and appliances” series from AEO 2013. The approach used to forecast the price trends 

and the results of the sensitivity cases are described in appendix 10C of this preliminary TSD. 

10.4.2.2 Annual Operating Cost Savings per Unit 

 The per-unit annual operating cost includes the costs for energy, repair, and maintenance. 

As described in chapter 8 of the preliminary TSD, DOE assumed that potential standards would 

not increase maintenance and repair costs for any of the considered product classes. Therefore, 

DOE determined the per-unit annual operating cost savings based only on the energy cost 

savings attributable to a standard level. DOE determined the per-unit annual operating cost 

savings by multiplying the per-unit savings in annual energy consumption for each product class 

by the appropriate energy price. 

 As described in chapter 8, DOE forecasted energy prices based on EIA’s AEO 2013. The 

energy price trends are described in chapter 8 of this preliminary TSD.

10.4.2.3 Total Annual Increases in Installed Cost 

 The total annual increase in installed cost for any given standards case is the product of 

the total per-unit increase in installed cost due to the standard and the number of units of each 

vintage. This approach accounts for differences in total installed cost from year to year. Below is 

the equation for calculating the increase in total annual installed cost for a given standards case 

(as introduced in section 10.4.1). 

 

∑ V UTICV TIC  STOCK 

10.4.2.4 Total Annual Savings in Operating Cost 

 The total annual savings in operating cost for any given standards case is the product of 

the annual operating cost savings per unit attributable to the standard and the number of units of 

each vintage. This approach accounts for differences in annual operating cost savings from year 

to year. Below is the equation for calculating the total annual operating cost savings for a given 

standards case (as introduced in section 10.4.1). 

 

∑ V UOCSV OCS  STOCK 
10-14

10.4.2.5 Discount Factors 

 DOE multiplies monetary values in future years by a discount factor to determine the 

present value. The discount factor (DF) is described by the equation: 

)(

_

)1(

1

y yp

r

DF





 

Where: 

R = discount rate, 

Y = year of the monetary value, and 

yP = year in which the present value is being determined. 

 DOE estimated national impacts using both a 3-percent and a 7-percent real discount rate,

in accordance with the Office of Management and Budget (OMB)’s guidance to Federal agencies 

on the development of regulatory analysis (OMB Circular A-4, September 17, 2003), and section 

E, “Identifying and Measuring Benefits and Costs,” therein. DOE defines the present year as 

2013.

10.4.2.6 Present Value of Costs 

 The present value of increased installed costs is the increase in annual installed cost in 

each year (i.e., the difference between a standards case and base case), discounted to the present 

and summed over the period for which DOE is considering the installation of products (that is, 

from 2019 to 2048).

 The increase in total installed cost refers to both product cost and installation cost 

associated with the higher energy efficiency of products purchased in the standards case 

compared to the base case. DOE calculated annual increases in installed costs as the difference in 

total installed cost for new products purchased each year multiplied by the shipments in the 

standards case. 

10.4.2.7 Present Value of Savings 

 The present value of operating cost savings is the annual operating cost savings (the 

difference between the base case and a standards case) discounted to the present and summed 

over the period from the compliance year, 2019, to the year when the last unit installed in 2048 is 

retired from service. Savings are decreases in operating costs associated with the higher energy 

efficiency of products purchased in the standards case compared to the base case. Total annual 

operating cost savings are the savings per unit multiplied by the number of units of each vintage 

that survive in a particular year. 
10-15

10.5 RESULTS OF CALCULATIONS 

 The national impact analysis (NIA) model estimates the NES and NPV attributable to a 

given candidate standard level. The inputs to the NIA model were discussed in sections 10.3.2 

(NES inputs) and 10.4.2 (NPV inputs). DOE generated the NES and NPV results using a 

Microsoft Excel spreadsheet, which is accessible on the Internet 

((http://www1.eere.energy.gov/buildings/appliance_standards/residential/dishwashers.html).

Details and instructions for using the spreadsheet are provided in appendix 10A of this 

preliminary TSD. 

10.5.1 Summary of Inputs 

 Table 10.5.1 summarizes the inputs to the NIA model. The data source for each input is 

described briefly. 

Table 10.5.1 Inputs to Calculation of National Energy Savings and Net Present Value 

Input Data Source

Shipments Annual shipments from shipments model. (See chapter 9.)

Effective date of standard 2019

Base-case forecasted efficiencies SWIEF determined in 2019 for each of the considered products

classes. SWIEF is held constant during the forecast period 2019–

2048. (See section 10.2.)

Standards-case efficiencies Roll-up scenario assumed for determining SWIEF in 2019 for 

each standards case and for each of the considered products 

classes. SWIEF is held constant during the forecast period 2019–

2048. (See section 10.2.)

Annual energy consumption per unit Annual weighted-average values are a function of SWAEU. (See 

section 10.3.2.3.)

Total installed cost per unit Annual weighted-average values are a function of the efficiency 

distribution. (See section 10.4.2.1.)

Energy cost per unit Annual weighted-average values are a function of the annual 

energy consumption per unit and energy prices. (See chapter 8, 

for energy prices.)

Repair and maintenance costs per unit Standards are assumed to induce no changes to repair or

maintenance costs.

Forecast of installed cost per unit Price forecast based on historical PPI data.

Forecast of energy prices Energy prices: EIA's AEO2013 projections (See chapter 8.)

Energy site-to-power plant

conversion

A time-series conversion factor that includes losses due to 

electricity generation, transmission, and distribution. Conversion, 

which changes yearly, is generated by DOE/EIA’s NEMS* 

program. 

Discount rate 3% and 7% real

Present year Future expenses are discounted to 2013.
10-16

Input Data Source

*Section 10.3.2.5 provides more detail on NEMS.

10.5.2 Results of National Energy Savings Calculations 

 Table 10.5.2 shows the NES results for the CSLs analyzed for dehumidifiers. NES 

results, which are cumulative to 2048, are shown as primary energy savings. DOE based the 

inputs to the NIA model on weighted-average values, yielding results that are discrete point 

values, rather than a distribution of values such as obtained in the LCC and PBP analysis 

(chapter 8 of the preliminary TSD).

Table 10.5.2 Cumulative National Energy Savings (Unit: Quads) 

CSL ≤20.00 

Pints/Day

20.01-

30.00 

Pints/Day

30.01-

35.00 

Pints/Day

35.01-

45.00

Pints/Day

>45.00 

Pints/Day

≤8.0 ft3

Case 

Volume

(WholeHome)

>8.0 ft3

Case 

Volume 

(Wholehome)

All

1 0.20 0.01 0.01 0.00 0.02 0.00 0.00 0.23

2 0.22 0.03 0.04 0.02 0.03 0.00 0.00 0.34

3 0.26 0.06 0.14 0.14 0.03 0.00 0.00 0.63

4 0.32 0.15 0.19 0.19 0.04 0.00 0.01 0.89

Table 10.5.3 Full-Fuel-Cycle National Energy Savings (Unit: Quads) 

CSL ≤20.00 

Pints/Day

20.01-

30.00 

Pints/Day

30.01-

35.00 

Pints/Day

35.01-

45.00 

Pints/Day

>45.00 

Pints/Day

≤8.0 ft3

Case 

Volume 

(WholeHome)

>8.0 ft3

Case 

Volume 

(Wholehome)

All

1 0.20 0.01 0.01 0.00 0.02 0.00 0.00 0.23

2 0.22 0.03 0.05 0.02 0.03 0.00 0.00 0.35

3 0.26 0.06 0.14 0.14 0.03 0.00 0.00 0.64

4 0.32 0.15 0.19 0.19 0.04 0.00 0.01 0.91

 

10.5.3 Annual Costs and Savings 

 To illustrate the basic inputs to the NPV calculations, Figure 10-2 presents the nondiscounted annual installed cost increases and annual operating cost savings nationwide for CSL 
10-17

3 for dehumidifiers. The figure also shows the net savings, which represent the difference 

between the savings and costs for each year. The annual product cost is the increase in the total 

installed cost for products purchased each year during the forecast period. The annual operating 

cost savings is the savings in operating costs for products operating in each year. The NPV is the 

difference between the cumulative annual discounted savings and the cumulative annual 

discounted costs. DOE could create figures like the one presented below for each CSL.

Figure 10-2 Non-Discounted Annual Installed Cost Increases and Annual 

Operating Cost Savings for Dehumidifiers, CSL 3 

10.5.4 Results of Net Present Value Calculations 

This section provides results from the calculation of net present value (NPV) for the 

potential efficiency standards for dehumidifiers. Results, which are cumulative, are shown as the 

discounted value of savings. DOE based the inputs to the NIA model on weighted-average 

values, yielding results that are discrete point values, rather than a distribution of values as 

produced by the life-cycle cost and payback period analysis. 

 The present value of increased total installed costs is the increase in total annual installed 

cost (i.e., the difference between the standards case and base case), discounted to the present and 

summed over the period in which DOE evaluated the impacts of standards (2019 to 2048).

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

0.60

Billion 2012$

Operating Cost Savings

Equipment Cost

Net Savings
10-18

 Savings are decreases in operating costs associated with the higher energy efficiency of 

products purchased in a standards case as compared to the base case. Total savings in operating 

costs are the savings per unit multiplied by the number of units of each vintage (i.e., the year of 

manufacture) that survive in a particular year. For units purchased through 2048, operating costs 

include energy consumed until the last unit is retired from service. 

 Table 10.2.8 and Table 10.2.9 presents NPV results for the candidate standard levels 

considered for dehumidifiers. 

Table 10.2.8 Cumulative NPV Results Based on 3-Percent Discount Rate (Billion, 2012$) 

CSL ≤20.00 

Pints/Day

20.01-30.00 

Pints/Day

30.01-

35.00 

Pints/Day

35.01-

45.00

Pints/Day

>45.00 

Pints/Day

≤8.0 ft3

Case 

Volume 

(WholeHome)

>8.0 ft3

Case 

Volume 

(WholeHome)

All

1 1.42 0.04 0.04 0.00 0.12 0.01 0.01 1.64

2 1.59 0.22 0.32 0.12 0.14 0.01 0.02 2.43

3 1.84 0.40 0.96 0.94 0.14 0.01 0.02 4.31

4 2.20 0.98 1.29 1.27 0.23 0.01 0.03 6.01

Table 10.2.9 Cumulative NPV Results Based on 7-Percent Discount Rate (Billion, 2012$) 

CSL ≤20.00 

Pints/Day

20.01-30.00 

Pints/Day

30.01-

35.00 

Pints/Day

35.01-

45.00

Pints/Day

>45.00 

Pints/Day

≤8.0 ft3

Case 

Volume 

(WholeHome)

>8.0 ft3

Case 

Volume 

(WholeHome)

All

1 0.61 0.02 0.02 0.00 0.05 0.00 0.00 0.70

2 0.68 0.09 0.14 0.05 0.06 0.00 0.01 1.04

3 0.78 0.17 0.40 0.38 0.06 0.00 0.01 1.80

4 0.92 0.41 0.54 0.54 0.09 0.00 0.01 2.51
10-19

REFERENCES 

 

1 United States. Office of the Federal Register. Federal Register, Volume 76, Number 160, 

 August 18, 2011, Pages 51281-51868. Washington D.C. UNT Digital Library.

2 U.S. Energy Information Administration. Annual Energy Outlook 2013 with Projections 

to 2040. 2013. Washington, DC. Report No. DOE/EIA-0383(2013). April. (Last accessed 

November 21, 2013.) <http://www.eia.gov/forecasts/aeo/pdf/0383(2013).pdf>