1

Technical and Editorial Corrections

• Definition of “Dehumidifier”

– DOE proposes to remove the word “refrigerated” from the phrase 

“mechanically refrigerated encased assembly ” in the dehumidifier 

definition in 10 CFR 430.2.

• Clarifies that moisture removal is the main function of this product.

• Is consistent with the EPCA definition (42 U.S.C. 6291(34))

– DOE also proposes to clarify that the definition of “dehumidifier” 

does not apply to portable air conditioners or room air conditioners.

• Correctly reference sections of Appendix X in 10 CFR 

430.23(z) for measuring capacity, EF, and IEF.

• Integrated Energy Factor Calculation

– DOE proposes to include the correct value of 6 for the constant that 

converts standby power.
2

Ambient Temperature

• 2009 Residential Energy Consumption 

Survey (RECS):

– 15 million total homes surveyed with 

dehumidifiers

– Majority of homes were in the 

Northeast (5.1 million) and Midwest 

(6.5 million)

• In 2006, AHAM submitted to DOE an 

estimate of 1,095 annual active mode 

operating hours

– 73.5% of operation falls between June 

and August

– 26.5% of operation occurs in April, 

May, September, and October

AHAM Estimated Usage

Month Operating Hours

Jan 0

Feb 0

Mar 0

Apr 14

May 86

Jun 231

Jul 288

Aug 288

Sep 130

Oct 58

Nov 0

Dec 0

Total 1,095

2009 RECS Data (homes in millions)

US Total 15

Region: Northeast 5.1

New England 1.5

Mid Atlantic 3.6

Region: Midwest 6.5

East North Central 4.5

West North Central 2

Usage by Location
3

Ambient Temperature

• Collected weather station data from the National Climatic Data Center 

(NCDC) of the National Oceanic and Atmospheric Administration (NOAA).

– Hourly ambient temperature and relative humidity

– Hourly soil temperature measured at a depth of 40 inches

• Data were analyzed for states* within the two regions with primary 

dehumidifier ownership, Northeast and Midwest, and according to RECS.

• All data with relative humidity < 60% was removed from the data set.

Northeast

New England

ME, NH, RI

Mid Atlantic

NY, PA

Midwest

East North 

Central

IL, IN, MI, OH, WI

West North 

Central

IA, KS, MN, MO, ND, NE, SD

*Hourly climate data were not available for all states in each sub-region 

(http://www.wcc.nrcs.usda.gov/scan/)

Ambient and Soil Temperature Data
4

Ambient Temperature

Example of Northeast Region Data

Average Ambient Temperature

Northeast April May June July August September October

New England 43.20 54.7 59.7 67.4 67.5 58.2 51.5

ME 40.69 52.04 57.93 65.20 65.97 55.58 49.29

NH 43.29 54.41 59.78 67.49 67.09 57.27 50.94

RI 45.66 57.58 61.50 69.49 69.40 61.71 54.21

Mid Atlantic 44.3 62.0 63.5 71.0 68.6 61.6 53.7

NY 42.30 60.46 62.22 69.09 67.26 59.81 53.15

PA 46.39 63.46 64.86 72.99 69.98 63.44 54.34

Average Soil Temperature at 40” Depth

Northeast April May June July August September October

New England 42.8 49.9 57.2 63.7 66.5 62.7 56.2

ME 39.49 47.67 55.38 62.33 64.81 61.20 54.77

RI 46.18 52.06 59.07 65.17 68.24 64.14 57.67

Mid Atlantic 50.4 58.0 66.4 71.8 72.8 69.4 61.9

NY 49.39 57.28 65.92 71.34 72.29 68.51 61.26

PA 51.45 58.70 66.87 72.30 73.27 70.26 62.55
5

Ambient Temperature

• Sub-region conditions and subsequent regional conditions were then 

combined using a weighted average based on RECS ownership data.

• Example –

• Using AHAM monthly usage estimates, national weighted average 

annual conditions were calculated.

Month of 

Operation

Average Monthly Temperature in 2012 when Hourly %RH>60, in °F (NOAA, NCDC) Weighted Average 

Northeast (Weighted) Overall Temperature

New 

England

Mid 

Atlantic Midwest (Weighted)

East North 

Central 

West North 

Central

Apr 44.01 43.21 44.35 46.22 46.05 46.61 45.25

May 59.82 54.68 61.96 58.43 59.55 55.93 59.04

Jun 62.42 59.74 63.54 64.03 63.96 64.17 63.32

Jul 69.97 67.39 71.04 71.32 71.72 70.44 70.73

Aug 68.28 67.49 68.62 64.37 64.87 63.24 66.09

Sep 60.61 58.19 61.63 56.31 57.66 53.27 58.20

Oct 53.08 51.48 53.74 45.73 47.20 42.41 48.96

2009 RECS Data (millions)

US Total 15

Region: Northeast 5.1

New England 1.5

Mid Atlantic 3.6

Region: Midwest 6.5

East North Central 4.5

West North Central 2

Month of 

Operation

Operating

Hours Weighted Average Ambient

Temperature (°F)

Weighted Average Soil 

Temperature (°F)

Apr 14 45.25 48.59

May 86 59.04 55.20

Jun 231 63.32 62.31

Jul 288 70.73 68.39

Aug 288 66.09 69.18

Sep 130 58.20 66.06

Oct 58 48.96 58.46

National Weighted Average Annual 

Ambient Temperature is 64.06 °F

National Weighted Average Annual 

Soil Temperature is 65.22 °F
6

Ambient Temperature

• Based on DOE’s analysis, national average annual ambient temperature and soil 

temperature at 40” depth in regions of dehumidifier use are both close to 65 °F

• This is consistent with ANSI/AHAM DH-1-2008 Low Temperature Test with conditions 

of 65 °F dry-bulb temperature and 60% RH.

• 433 national annual operating hours are at 65 °F test conditions (65 °F ± 2 °F) 

• 112 national annual operating hours are at 80 °F test conditions (80 °F ± 2 °F)

0

20

40

60

80

100

120

140

160

30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90

Hours

Temperature (°F)

Overall Hours per Ambient Temperature (relative humidity >60%)

Representative Ambient Temperature
7

Ambient Temperature

Whole-Home Dehumidifier Ambient Temperature

• Commenters suggested that the dry-bulb temperature of the inlet air 

for whole-home dehumidifiers is different than portable dehumidifiers 

and would be close to the thermostat setting in the home.

• RECS provides average indoor temperature for three scenarios based on 

1,735 homes in the Northeast and Midwest:

– Daytime when the residence is occupied,

– Daytime when the residence is unoccupied, and

– Nighttime when the residence is occupied.

• According to RECS, the average indoor temperature is 72.7 °F.

Time of Day Occupied Season Temperature (°F)

Day Yes Summer 72.3

Day No Summer 73.7

Night Yes Summer 72.2

Average 72.7

Number of Homes 1,735
8

Ambient Temperature

• Capacity and EF are calculated based on measured condensate 

collected and energy consumed during the 6 hour rating test 

period. 

Product Capacity and EF Calculation Review

CCCCCCCCCCCCCCCC

pp pp

dd

=

CCCC CC CCCCCC llll × 24 hrr

DDDD oo TT hrr × 1.04

llllHH2OO

pp ppHH2OO

EEEE

LL

kkkk

=

CCCC CC CCCCCC llll × 0.454 kkkk

llll

EE CCCC CCCC kkkk × 1.0 kkkkHH2OO

ll HH2OO

*Additional details and full equations are found in Sections 7.1.7 and 7.2.2 of ANSI/AHAM DH-1-2008.
9

Ambient Temperature

Performance Impacts at Reduced Temperature – Portable

• When a dehumidifier operates at a lower 

temperature, heat transfer capabilities in the system 

are decreased, thereby reducing capacity and 

performance.

• DOE investigated dehumidification mode performance 

of 13 portable and 10 whole-home dehumidifiers 

(ducted with 0.5” H2O except as noted) when tested 

according to the proposed 65 °F test conditions.

• EF was examined because it is directly impacted by 

temperature. IEF would factor in combined low-power 

mode energy use.

• Test results demonstrated an average reduction in 

capacity per product class of 35–53% and EF of 21-

36%.

• The alternate approach to combine two test 

conditions would still result in a significant impact, as 

the 65 °F condition would be assigned a 79% 

weighting.

Product Class

(pints / day) Test Unit

Percent Change 

from 80 °F to 65 °F (%)

Capacity EF

< 35.00 P1 -35 -26

Class Average -35 -26

35.01 - 45.00

P2 -77 -61

P3 -48 -32

P4 -33 -15

Class Average -53 -36

45.01 - 54.00

P5 -39 -25

P6 -33 -21

P7 -36 -21

Class Average -36 -22

54.01 - 75.00

P8 -61 -39

P9 -39 -32

P10 -65 -36

P11 -59 -35

P12 -36 -14

Class Average -52 -31

> 75.00

P13 -27 -15

W3 -35 -21

W4 -42 -29

W5 -49 -26

W7 -27 -15

W8 -24 5

W9 -49 -33

W10 -20 -4

W12 -42 -35

W13 -45 -35

W14* -39 -25

Class Average -36 -21

* Unducted
10

Ambient Temperature

• DOE numerically estimated wholehome dehumidifier performance at the 

alternate test condition of 73 °F drybulb temperature and 60% RH, ducted 

with 0.5” H2O .

• Numerical estimations were 

determined for capacity and EF using

biquadratic equations as a function of 

temperature and relative humidity.*

*In this case, relative humidity is held constant at 60%, and the equation therefore simplified to a 

quadratic equation with terms that scale with the temperature and square of the temperature.

Test 

Unit

Dehumidification 

Technology

Percent Change 

from 80 °F to 73 °F (%)

Capacity EF

W3 Refrigerant -15 -6

W4 Refrigerant -18 -9

W5 Refrigerant -21 -8

W7 Refrigerant-Desiccant -12 -5

W8 Refrigerant -10 2

W9 Refrigerant -21 -10

W10 Refrigerant -9 -1

W12 Refrigerant-Desiccant -18 -11

W13 Refrigerant -19 -11

Average -16 -7

Performance Impacts at Reduced Temperature – Whole-Home

CCCCCCCCCCCCCCCC oooo EEEE = AA × TTTTTT 22 + BB × TTTTTT + CC × RRRR22 + DD × RRRR + EE × TTTTTT × RRRR + 

CCCCCCCCCCCCCCCC oooo EEEE = GG × TTTTTT 22 + × TTTTTT + II
11

Relative Humidity

• American Society of Heating, Refrigerating and Air-Conditioning 

Engineers (ASHRAE) 55 - Thermal Environmental Conditions for 

Human Occupancy

– Identifies 0.012 humidity ratio (lbH2O/lbair) as upper comfort limit

– Corresponds to 55% RH at 80 °F or ≥60%RH at lower temperatures

• U.S. Department of Labor, Occupational Safety and Health 

Administration (OSHA) Technical Manual

– Recommends relative humidity be maintained between 20% and 60%

• CADMUS Group Field Study

– Average consumer-selected setpoint was 50% RH and ranged from 35% 

to 65%

– Values are not representative of ambient %RH while dehumidifying, only 

the consumer setpoint at which dehumidification ceases

DOE reviewed studies and conducted additional research
12

Relative Humidity

• DOE Metering Study

– On average, 5% of hours were spent at >60% RH.

– 3 of the 10 sites exceeded 60% RH for 15 to 25% of the time.

• Wisconsin Energy Center Field Study

– 11 of 40 sites exceeded 60% RH for at least 25% of the summer.

– 16 of 40 sites ranged from 50 to 60% RH for at least 25% of the summer.

• Manufacturer Literature

– Based on DOE research of various manufacturers and brands, most 

common default RH setpoint is 60%.

Studies and Research, continued
13

Whole-Home Dehumidifiers

Duct Configuration: Horizontal Inlet Duct
14

Whole-Home Dehumidifiers

Duct Configuration: Horizontal Outlet Duct
15

Whole-Home Dehumidifiers

Duct Configuration: Vertical Inlet Duct
16

Whole-Home Dehumidifiers

Duct Configuration: Vertical Outlet Duct
17

Whole-Home Dehumidifiers

• DOE reviewed several standards for static pressure accuracy 

requirements.

– AMCA 210-07 specifies a pressure measurements have a maximum 

uncertainty of 0.005” H2O at the proposed 0.5” H2O 

– ANSI/ASHRAE Standard 37-2009, “Methods of Testing for Rating 

Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment”, 

specifies a static pressure accuracy of ±0.01” H2O

– Appendix M to 10 CFR Part 430 subpart B, section 2.5.3 for testing 

central air conditioners and heat pumps specifies that the differential 

pressure instrument shall have a resolution of no more than 0.01” H2O

• DOE proposed that pressure instruments have an accuracy 

within ±0.01” H2O

– Consistent with ASHRAE 37-2009 and Appendix M

– Less burdensome than the 0.005” H2O in AMCA 210-07.

Static Pressure Accuracy
18

Certification

• The capacity for each basic model must be reported, but the 

current test procedure does not specify how to determine the 

rated capacity.

• The consequence of an incorrectly reported capacity may be 

the application of an incorrect standard.

• DOE proposed to specify in 10 CFR 429.36 that the average of 

the capacities measured for a given sample of a basic model be 

used for certification purposes.
19

Verification

• DOE proposed to require in 10 CFR 429.134(f) that measured 

capacity be within 5 percent of the certified capacity, or 1 

pint/day, whichever is greater.

– If this condition was met, the certified capacity would be used to 

determine the minimum allowable EF for the basic model

– If this condition was not met, the mean of the measured capacities 

would be used to determine the minimum allowable EF

• This tolerance is the same as for AHAM’s dehumidifier 

verification program.

• DOE also proposed to clarify in 10 CFR 430.23(z) the specific 

sections in Appendix X and Appendix X1 which would be used 

to measure capacity, and provide rounding instructions for 

capacity and IEF.
20

Compliance Dates

• Amended Appendix X1:

– Clarifications and corrections would not affect a manufacturer’s ability to 

comply with current standards

– Would be required for representations 180 days after the publication of 

the final rule

• New Appendix X1:

– May be used for early compliance with any amended standards

– Would be required for use upon the compliance date of amended 

standards
21

Small Business Impacts

• DOE identified five small business manufacturers .

• Impacts of reduced ambient test temperature: 

– AHAM DH-1-2008 includes a test at 65 °F, which suggests that some

manufacturers already test at the proposed lower temperature.

• DOE estimated the costs associated with the proposal.

– Whole-home test ducts: 

• Refrigeration-only whole-home dehumidifier: $1,500 to $3,000 

• Refrigerant-desiccant dehumidifier: $8,100

– Fan-only mode test can use the same measurement devices as the 

current test procedure.

• Cost of additional meter: $2,000 (if needed)

– Proposed limit of one psychrometer per dehumidifier test could 

require the purchase of additional psychrometers.

• Cost to purchase and calibrate one psychrometer: $1000

• Cost of sampling tree: $300
22

Small Business Impacts

• Testing at both 80 °F and 65 °F would double the 

dehumidification mode test burden

• DOE considered chilled mirror hygrometers to measure wetbulb temperature in test ducts, but proposed the use of 

aspirating psychrometers to avoid the high cost and burden 

of using hygrometers.

• DOE could require that test ducts be used for both the inlet 

and outlet ports rather than only the outlet port.

– Cost of extra test duct: $3000.

Proposal Alternatives
23

Backup Slides for Standards
24

Markups Analysis

• Manufacturer Markups

– DOE used 10-K reports of dehumidifier manufacturing companies from 

2008 to 2012.

– DOE assumed baseline dehumidifier units have the same markup as 

more efficient units.

– DOE assumed whole-home manufacturers has the same markup as 

portable manufacturing companies.

• Retail Markups for Portable Dehumidifiers

– DOE used U.S. Census Bureau Business Expenses Survey for “Household 

Appliance Stores”

• Distributor Markups for Whole-home Dehumidifiers

– DOE used 2007 Economic Census industrial cost data.

– DOE derived the baseline and incremental markups for both 

replacement and first time owner markets. 
25

Markups Analysis

• DOE applies markups to product MSP to determine the 

customer purchase price of analyzed equipment.

• DOE used baseline and incremental markups, applied to the 

MSP in the base case, and the incremental difference in MSP 

in each standards case for portable and whole-home 

dehumidifiers. 

Markup Baseline Incremental

Manufacturer 1.43

Retailer 1.36 1.11

Sales Tax 1.071

Overall 2.08 1.70

Markup Replacement First Time Owner

Baseline Incremental Baseline Incremental

Manufacturer 1.43 1.43

Wholesaler 1.36 1.10 1.36 1.10

Mechanical 

Contractor 1.53 1.22 1.45 1.15

General 

Contractor -- 1.47 1.34

Sales Tax 1.071 --

Overall 3.19 2.06 4.15 2.42

Portable Dehumidifiers

Whole-Home Dehumidifiers
26

Markups Analysis

• Consumer Price = Manufacturing Cost × Markups × Sales Tax

– Manufacturing cost vs. efficiency relationships developed in the 

Engineering Analysis

– Markups and Sales Taxes developed in the Markups Analysis to 

determine product price

Std-Level 

Manufacturer 

Cost

Baseline 

Manufacturer 

Cost

Manufacturer 

Markup

Retailer or 

Distributor 

Markup

Sales Tax

Consumer Price

Consumer Price
27

Energy Use Analysis

• Portray the variability of annual energy use for portable 

dehumidifiers using household samples from RECS 2009.

CCDD: Climate Controlled, Direct Drain CCB: Climate Controlled, with bucket

NCCDD: Non-Climate Controlled, Direct Drain NCCB: Non-Climate Controlled, with bucket

Fan Run Time

Variability: Portable Dehumidifier
28

Energy Use Analysis

• DOE also used the probability 

distribution of operating hours by mode 

found in Willem’s (2013b) report. 

• DOE also used the probability 

distribution of power demand for Fanonly mode (131-158 W) and Standby 

mode (2.6-4.2 W) in Willem’s (2013b) 

report. 

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

Probability Distribution (%)

Hours

Hours/day in Compressor Mode

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

Probability Distribution (%)

Hours

Hours/day in Fan-only Mode

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Probability Distribution (%)

Hours

Hours/day in Standby Mode

Variability: Whole-Home Dehumidifiers
29

Operating Costs: Electricity Prices Geographic Area Average Price 

(2012$/kWh) Geographic Area Average Price 

(2012$/kWh)

Connecticut, Maine, New Hampshire, 

Rhode Island, Vermont

0.174 Delaware, DC, Maryland, West 

Virginia 0.132

Massachusetts 0.151 Georgia 0.114

New York 0.197 North Carolina, South Carolina 0.108

New Jersey 0.166 Florida 0.118

Pennsylvania 0.137 Alabama, Kentucky, Mississippi 0.104

Illinois 0.122 Tennessee 0.102

Indiana, Ohio 0.112 Arkansas, Louisiana, Oklahoma 0.094

Michigan 0.136 Texas 0.114

Wisconsin 0.133 Colorado 0.115

Iowa, Minnesota, North Dakota, South 

Dakota

0.108 Idaho, Montana, Utah, Wyoming 0.091

Kansas, Nebraska 0.103 Arizona 0.113

Missouri 0.100 Nevada, New Mexico 0.117

Virginia 0.109 California 0.151

Alaska, Hawaii, Oregon, 

Washington

0.118

Source: EIA Form 861

Life-Cycle Cost and Payback Period Analysis
30

Operating Cost Inputs: Average Residential Electricity Prices

0.90

0.95

1.00

1.05

1.10

1.15

1.20

1.25

Electricity Price Trend (2012=100)

AEO 2013 Electricity Projection (National)

Reference Case High Low

Life-Cycle Cost and Payback Period Analysis