7-A-i

APPENDIX 7-A. RECS 2005 VARIABLES AND VALUES

TABLE OF CONTENTS

7-A.1 INTRODUCTION .................................................................................................7-A-1

7-A.2 SAMPLE DETERMINATION..............................................................................7-A-1

7-A.3 RECS 2005 DATABASE VARIABLE RESPONSE CODES..............................7-A-5

LIST OF TABLES

Table 7-A.2.1 Selection of RECS 2005 Records for Furnace Fans..................................7-A-2

Table 7-A.2.2 List of RECS 2005 Variables Used for Furnace Fans ...............................7-A-3

Table 7-A.3.1 Definitions of RECS 2005 Variables Used in Life-Cycle Cost Analysis..7-A-5

 
7-A-1

APPENDIX 7-A. RECS 2005 VARIABLES AND VALUES

7-A.1 INTRODUCTION

Using Microsoft ACCESS, DOE created a database containing a subset of the records 

and variables from DOE’s Energy Information Administration (EIA)’s RECS 2005.1 DOE used 

this RECS subset in the life-cycle cost (LCC) analysis of the Furnace Fan Rulemaking. This 

appendix explains the variable name abbreviations and provides definitions of the variable 

values. For the entire RECS 2005 dataset, refer to 

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

7-A.2 SAMPLE DETERMINATION

The subset of RECS 2005 records used to study furnace fans met all of the following 

criteria:

• used a furnace as the main or secondary source of heat;

• used a heating fuel that is natural gas, liquefied petroleum gas (LPG), fuel oil, or 

electricity;

• heated only one housing unit; and

• had an energy consumption greater than zero.

DOE divided the furnace subset into several subsets designed to include households that 

use one of the three furnace product classes (Table 7-A.2.1). 

The RECS 2005 weighting indicates how commonly each household configuration 

occurs in the general population. DOE made some adjustments to EIA’s weightings for each 

RECS 2005 household in order to create a furnace fan population weight for 2018. The first 

adjustment was to compensate for the fact that the RECS 2005 sample does not distinguish 

between weatherized and non-weatherized gas furnaces. Therefore, to account for the furnace 

fans associated with non-weatherized gas furnaces, DOE assumed that a fraction of the 

households in the south with both a central air conditioner and gas furnace were using 

weatherized furnaces. Based on AHRI shipment data for weatherized and non-weatherized

furnaces (which shows that about 10% of total furnace shipments are weatherized furnaces), 

DOE multiplied the RECS 2005 weight for households in the south region with both a central air 

conditioner and gas furnace by 0.80.2

 It was assumed that 25 percent of the south region 

shipments would be condensing by 2018, therefore 25 percent of the households in the south 

were assigned to the non-weatherized non-condensing furnace fans product class.

DOE also took into account the growth in population by region from 2005 to 2018 based 

on U.S. census population projections.3 Finally, DOE adjusted the weightings to account for 

households with multiple furnaces. According to the 2008 American Comfort Survey, 7 percent 

of households in the U.S. have multiple gas furnaces.4 For the sake of simplicity, DOE assumed 

that these households had two furnaces. Therefore, for 7 percent of the households, the weighting 
7-A-2

was doubled, so it could be representative of the furnace weight. DOE believes that the 

household records, along with their adjusted weightings, are representative of housing 

nationwide in 2018.

Table 7-A.2.1 Selection of RECS 2005 Records for Furnace Fans

Product Class Algorithm No. of 

Records

RECS 

2005

DOE 

2018

Number 

of 

Houses 

million

Number 

of 

Furnace

s million

Non-Weatherized, 

Non-Condensing Gas 

Furnace Fan

Primary or Secondary Heating Equipment = Gas Furnacea

Region = South

Housing Type = non-mobile home

736 19.6 14.5

Non-Weatherized, 

Condensing Gas 

Furnace Fan

Primary or Secondary Heating Equipment = Gas Furnace

Housing Type = non-mobile home

1726 45.5 35.6

Weatherized Gas 

Furnace Fan

Primary or Secondary Heating Equipment = Gas Furnace

Region = South

Housing Type = non-mobile home

Primary or Secondary Cooling Equipment = Central Air 

Conditioner

565 15.6 3.6

Oil Furnace Fan Primary or Secondary Heating Equipment = Oil Furnace

Housing Type = non-mobile home

150 2.9 3.3

Electric Furnace / 

Modular Blower Fan

Primary or Secondary Heating Equipment = Electric Furnace

Housing Type = non-mobile home

576 15.4 17.9

Manufactured Home 

Non-Weatherized, 

Non-Condensing Gas 

Furnace Fan

Primary or Secondary Heating Equipment = Gas Furnace

Region = South

Housing Type = mobile home

51 1.2 1.2

Manufactured Home 

Non-Weatherized, 

Condensing Gas 

Furnace Fan

Primary or Secondary Heating Equipment = Gas Furnace

Housing Type = mobile home

109 2.5 1.6

Manufactured Home 

Electric Furnace / 

Modular Blower Fan

Primary or Secondary Heating Equipment = Electric Furnace

Housing Type = mobile home

68 1.9 2.1

Hydronic Air 

Handler Fan 

(Heat/Cool)

Primary or Secondary Heating Equipment = Gas Furnace

Region = South

Housing Type = non-mobile home

Primary or Secondary Cooling Equipment = Central Air 

Conditioner

Water Heater Equipment = Gas Water Heater

Household Square Footage <2000 sq ft

40 1.3 0.8

 

a Natural Gas or LPG Furnace.
7-A-3

Table 7-A.2.2 lists the variables use in the analysis. 

Table 7-A.2.2 List of RECS 2005 Variables Used for Furnace Fans

Variable Description

Location Variables

REGIONC Census region

DIVISION Census division

LRGSTATE Four largest states

CD65 Cool Deg-Days: Base65 01 TO 12-2005 (Inoculated)

HD65 Heat Deg-Days: Base65 01 TO 12-2005 (Inoculated)

Household Characteristics Variables

DOEID 4-digit identification number

NWEIGHT The Final Weight

TYPEHUQ Type of Home (Respondent answer)

YEARMADE Year Home Built

STORIES Reported Stories in Housing Unit

BTUNGSPH Natural Gas Space Heat Use (Estimated)

BTULPSPH LPG Space Heat Use (Estimated)

BTUFOSPH Fuel Oil Space Heat Use (Estimated)

BTUELCOL Electric AC Use (Estimated)

EQUIPM Type of heating equipment provides the heat

FUELHEAT Main fuel used for heating home

HEATOTH Main heating system also heat other apartments

DNTHEAT Have any heating equipment Use it or not

HEATOFF Number of rooms not heated last winter

WARMAIR Sec Ht Eqp Central warm-air furnace with ducts

FURNFUEL What fuel used in secondary warm air furnace

REVERSE Sec Ht Eqp Heat pump

EQUIPAGE How old is equipment identified in D-2 heat system

EQUIPAUX Use any other types of equipment to heat home
7-A-4

UGASAUX Secondary heating fuel - Natural Gas

LPGAUX Secondary heating fuel - LPG

FOILAUX Secondary heating fuel - Fuel Oil

ELECAUX Secondary heating fuel - Electricity

EQMAMT How much heat main heating equipment provides

NUMTHERM How many thermostats are used

COOLTYPE What kind of air-conditioning equipment you have

CENACHP Is your central AC system a heat pump

USECENAC How household uses central AC during the summer

AGECENAC How old is your households central AC equipment

ACOTHERS The central AC also cool apartments condos

NUMBERAC Number of window or wall AC units in your home

USEWWAC How household uses window AC

WWACAGE How old is households most-used window/wall unit

FUELH2O Fuel used for heating water washing or bathing

WHEATOTH Main equipment also heat water for apartments

WHEATSIZ Size of households main water heater tank

NCOMBATH Number of Complete Baths

WHEATAGE How old is your households main water heater

WeatherLocationID Weather Location ID based on closest fit of HDD and CDD*

TOTSQFT Total square footage

TOTHSQFT Total heated square footage

TOTCSQFT Total air-conditional square footage

NHSLDMEM How many people normally live in this household

NUMTHERM How many thermostats are used

Seniors Senior Only Household*

POOR100 Below 100 percent of poverty

HHINCOME Mid-point of MONEYPY range

* Not part of RECS 2005 variables.
7-A-5

7-A.3 RECS 2005 DATABASE VARIABLE RESPONSE CODES

Table 7-A.3.1 provides the response codes for all RECS 2005 variables used in the 

Heating Products samples.

Table 7-A.3.1 Definitions of RECS 2005 Variables Used in Life-Cycle Cost Analysis 

Variable Definition

ACOTHERS The central AC also cool apartments condos

1 = Yes

0 = No

9 = Legitimate Skip

AGECENAC How old is your households central AC equipment

1 = Less than 2 years old

2 = 2 to 4 years old

3 = 5 to 9 years old

4 = 10 to 19 years old

5 = 20 years or older

96 = Don’t know

99 = Legitimate skip

BTUELCOL Electric AC use estimated (in thousands of BTU 1- 9999998)

9999999=Not Applicable

BTUFOSPH Fuel Oil Space Heat use estimated (in thousands of BTU 1-

9999998)

9999999=Not Applicable

BTULPSPH LPG space heating use estimated (in thousands of BTU 1-

9999998)

9999999=Not Applicable

BTUNGSPH Natural gas space heating use estimated (in thousands of BTU 1-

9999998)

9999999=Not Applicable

CD65 Number of degree days

CELLAR Home has a basement

1 = Yes

0 = No

9 = Legitimate Skip

CENACHP Is your central AC system a heat pump 

1 = Yes

0 = No

9 = Legitimate Skip

COOLTYPE What kind of air-conditioning equipment you have 

1 = A central system

2 = Individual units in the window or walls

3 = Both central and individual units

9 = Legitimate skip
7-A-6

DIVISION Census division

1 = New England

2 = Middle Atlantic

3 = East North Central

4 = West North Central

5 = South Atlantic

6 = East South Central

7 = West South Central

8 = Mountain

9 = Pacific

DNTHEAT Have any heating equipment Use it or not 

1 = Have equipment, but don’t use it

2 = Don’t have any heating equipment

9 = Legitimate skip

DOEID Sample ID (1-4382)

ELECAUX Secondary heating fuel - Electricity 

1 = Yes

2 = No

EQMAMT How much heat main heating equipment provides

1 = Almost all

2 = About three-fourths

3 = Closer to half

9 = Legitimate Skip

EQUIPAGE Age of main heating equipment

1 = Less than 2 years old

2 = 2 to 4 years old

3 = 5 to 9 years old

4 = 10 to 19 years old

5 = 20 years or older

6 = Don't know

9 = Legitimate Skip

EQUIPAUX Use any other types of equipment to heat home 

1 = Yes

2 = No
7-A-7

EQUIPM Type of heating equipment provides the heat

4 = Heat pump

3 = Central warm-air furnace with ducts

2 = Steam/hot water system with radiators

5 = Built-in electric units installed in walls

6 = Built-in floor/wall pipeless furnace

7 = Built-in heater burning gas, oil, kerosene

8 = Heating stove burning wood, coal, coke

10 = Portable electric heaters

11 = Portable kerosene heaters

9 = Fireplace

12 = Cooking stove used to heat and cook

14 = Geothermal heat pump

21 = Equipment not listed

00 = No heating equipment used

FOILAUX Secondary heating fuel - Fuel Oil 

1 = Yes

2 = No

FUELH2O Fuel used for heating water

1 = Natural gas from underground pipes

2 = Bottled gas (LPG or propane)

3 = Fuel oil

4 = Kerosene

5 = Electricity

7 = Wood

8 = Solar

21 = Other

95 = Don’t use hot water

FUELHEAT Main fuel used for heating home

1 = Natural gas from underground pipes

2 = Bottled gas (LPG or propane)

3 = Fuel oil

4 = Kerosene

5 = Electricity

7 = Wood

8 = Solar

9 = District steam

10 = Coal

21 = Other

99 = Don’t heat home
7-A-8

FURNFUEL What fuel used in secondary warm air furnace 

1 = Natural gas from underground pipes

2 = Bottled Gas (LPG or Propane)

3 = Fuel oil

4 = Kerosene

5 = Electricity

7 = Wood

8 = Solar

21 = Other

99 = Legitimate Skip

HD65 Number of degree days

HEATOFF Number of rooms not heated last winter 

0 = Turned off all the time

1 = Turned on only a few days or nights

2 = Turned on quite a bit

3 = Turned on just about all winter

9 = Legitimate skip

HEATOTH Does the main space heating equipment also heat other residences?

1 = Yes

0 = No

HHINCOME Number of dollars (0-120.000)

LPGAUX Secondary heating fuel - LPG 

1 = Yes

0 = No

LRGSTATE Large state designation

0 = Other

1 = New York State

2 = California

3 = Texas

4 = Florida

NCOMBATH Number of Full Bathrooms (0-9)

NHSLDMEM Number that live in household (1-15)

NUMBERAC Number of window or wall AC units (0-15)

99 = Legitimate skip

NUMTHERM How many thermostats are used 

1 = Yes

0 = No

9 = Legitimate skip

NWEIGHT Sample weight

POOR100 Household is below 100 percent of poverty

1 = Poor 100%

0 = Nonpoor

REGIONC Census region

1 = Northeast 

2 = Midwest 

3 = South 

4 = West 
7-A-9

REVERSE See Ht Eqp Heat Pump

1 = Yes

0 = No

9 = Legitimate skip

STORIES Reported Stories in Housing Unit

10 = One story

20 = Two stories

31 = Three stories

32 = Four or more stories

40 = Split-level

55 = Some other type

99 = Legitimate skip

TOTCSQFT Total air-conditional number of square feet (0-9999)

TOTHSQFT Total heated number of square feet (0-9999)

TOTSQFT Total number of square feet (0-9999)

TYPEHUQ Respondents reported type of home

1 = Mobile Home

2 = Single-family detached house

3 = Single-family attached house

4 = Apartment building with 2-4 units

5 = Apartment building with 5 or more units

UGASAUX Secondary heating fuel - Natural Gas 

1 = Yes

0 = No

USECENAC How household uses central AC during the summer 

0 = Not used at all

1 = Turned on only a few days or nights

2 = Turned on quite a bit

3 = Turned on just about all summer

9 = Legitimate skip

USEWWAC How household uses window AC

0 = Not used at all

1 = Turned on only a few days or nights

2 = Turned on quite a bit

3 = Turned of just about all summer

9 = Legitimate skip

WARMAIR Sec Ht Eqp Central warm-air furnace with ducts 

1 = Yes

2 = No

9 = Legitimate skip

WeatherLocationID Weather Location ID based on closest fit of HDD and CDD*
7-A-10

WHEATAGE How old is your household's main water heater

0 = No separate water heater

1 = Less than 2 years old

2 = 2 to 4 years old

3 = 5 to 9 years old

4 = 10 to 19 years old

5 = 20 years or older

6 = Don't know

9 = Don’t use hot water

WHEATOTH Main equipment also heat water for apartments

1 = Yes

0 = No

9 = Don’t use hot water 

WHEATSIZ Size of household's main water heater tank

0 = Don’t have a separate water heater

1 = Small (30 gallons or less)

2 = Medium (31 to 49 gallons)

3 = Large (50 gallons or more)

6 = Have a tankless water heater

9 = Don’t use hot water

WWACAGE How old is households main water heater

1 = Less than 2 years old

2 = 2 to 4 years old

3 = 5 to 9 years old

4 = 10 to 19 years old

5 = 20 years or older

6 = Don’t know

9 = Legitimate skip

YEARMADE Year home built

1 = Before 1940

2 = 1940-49

3 = 1950-59

4 = 1960-69

5 = 1970-79

6 = 1980-84

7 = 1985-89

8 = 1990-94

9 = 1995-99

10 = 2000-2002

11 = 2003

12 = 2004

13 = 2005

* Not part of RECS 2005 variables.
7-A-11

REFERENCES

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

Consumption Survey: 2005 Public Use Data Files, 2008.

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

2. Air-Conditioning Heating and Refrigeration Institute, AHRI Regional Furnace Shipments 

Data, 2010. (Posted Submitted to DOE on July 20, 2010) 

<http://www.ahrinet.org/Content/Furnaces_609.aspx>

3. U.S. Department of Commerce-Bureau of the Census, Table A1: Interim Projections of 

the Total Population for the United States and States: April 1, 2000 to July 1, 2030, in 

Population Division, Interim State Population Projections. 2005. 

4. Decision Analysts, 2008 American Home Comfort Study: Online Database Tool, 2009. 

Arlington, Texas. <http://www.decisionanalyst.com/Syndicated/HomeComfort.dai>