7-D-i

APPENDIX 7-D. RECS 2005 VARIABLES AND VALUES

TABLE OF CONTENTS

7-D.1 INTRODUCTION .................................................................................................7-D-1

7-D.2 SAMPLE DETERMINATION..............................................................................7-D-1

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

LIST OF TABLES

Table 7-D.2.1 Selection of RECS 2005 Records for Furnaces.........................................7-D-2

Table 7-D.2.2 List of RECS 2005 Variables Used for Furnaces ......................................7-D-2

Table 7-D.3.3 Definitions of RECS 2005 Variables Used in Life-Cycle Cost Analysis..7-D-5

 
7-D-1

APPENDIX 7-D. RECS 2005 VARIABLES AND VALUES

7-D.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 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-D.2 SAMPLE DETERMINATION

The subset of RECS 2005 records used to study furnaces 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), or fuel oil;

• heated only one housing unit; and

• had an energy consumption greater than zero.

DOE divided the furnace subset into three further subsets designed to include households 

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

DOE made some adjustments to EIA’s weightings for each RECS 2005 household, in 

order to create a furnace population weight for 2016. The RECS 2005 weighting indicates how 

commonly each household configuration occurs in the general population. 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 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

 

DOE also took into account the growth in population by region from 2005 to 2016 based 

on U.S. census population projections.3

 For all product classes, the number of houses in the 

north were multiplied by a factor of 0.96 and the number of houses in the south by a factor of 

1.04. 

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 simplicity DOE assumed that these households had two furnaces. 

Therefore, for 7 percent of the households, the weighting was doubled, so it could be 
7-D-2

representative of the furnace weight. DOE believes that the household records, along with their 

adjusted weightings, are representative of housing nationwide in 2016.

Table 7-D.2.1 Selection of RECS 2005 Records for Furnaces

Product Class Algorithm Region No. of 

Records

RECS 

2005

DOE 

2016

Number 

of 

Houses 

(million)

Number 

of 

Furnaces 

(million)

NonWeatherized 

Gas Furnace

Central heating equipment = furnace

Heating fuel = gas

Home type = single or multi-family

Number of Housing Units Heated = 1

National 1726 45.5 45.2

North 990 25.9 26.9

South 736 19.6 18.3

Manufactured 

Home Gas 

Furnace

Central heating equipment = furnace

Heating fuel = gas

Home type = manufactured home

Number of Housing Units Heated = 1

National 109 2.5 2.5

North 58 1.2 1.2

South 51 1.2 1.3

Oil-Fired 

Furnace

Central heating equipment = furnace

Heating fuel = fuel oil

Home type = manufactured home

Number of Housing Units Heated = 1

National 150 2.9 3.0

DOE divided the furnace subset into three further subsets designed to include households 

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

Table 7-D.2.2 List of RECS 2005 Variables Used for Furnaces

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
7-D-3

TYPEHUQ Type of Home (Respondent answer)

YEARMADE Year Home Built

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

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

EQUIPAUX Use any other types of equipment to heat home

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

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

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
7-D-4

NCOMBATH Number of Complete Baths

WHEATAGE How old is your households main water heater

NHSLDMEM How many people normally live in this household

ATHOME Is someone at home all day on a typical weekday

DISHWASH Does your household use an automatic dishwasher

CWASHER Use a clothes washer in home

PGASHTWA Who pays natural gas for hot water

LPGPAY Who pays for bottled gas

CELLAR Home Has Basement

BASEFIN Is the basement finished

BASEHEAT Basement/crawl Space heated

BASECOOL Is basement air-conditioned

PRKGPLC1 Home has Garage or Carport

CRAWL Home Has Crawl Space

ATTIC Home has attic

ATTICFIN Part of the attic finished

ATTCHEAT How much of the attic is warm

ATTCCOOL Is the attic air-conditioned

STORIES Reported Stories in Housing Unit

NAPTFLRS Number of floors in this apartment

HIGHCEIL Any cielings over 8 feet high

CATHCEIL Any cathederal cielings

WALLTYPE Exterior Wall Construction Material

WELLPUMP Electric pump for well water

TEMPHOME Setting During the day when someone is home

TEMPGONE Setting During the day when no one is home

TEMPNITE Setting During sleeping hours

TEMPHOMEAC Setting During the day when someone is home

TEMPGONEAC Setting During the day when no one is home
7-D-5

TEMPNITEAC Setting During sleeping hours

NUMTHERM How many thermostats are used

TOTSQFT Total square footage

TOTBASESQFT Total Basement square footage

TOTGARGSQFT Total Garage square footage

TOTATTCSQFT Total Attic square footage

TOTRHMSQFT Total all other areas

TOTHSQFT Total heated square footage

TOTCSQFT Total air-conditional square footage

POOR100 Below 100 percent of poverty

UGASHERE Natural gas from underground pipe available

USENG HH uses utility gas

* Not part of RECS 2005 variables.

7-D.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-D.3.3 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

ATHOME Is there a household member at home all day on a typical 

weekday?

1 = Yes

0 = No
7-D-6

ATTCCOOL Is the attic air-conditioned

1 = Yes

0 = No

9 = Legitimate Skip

ATTCHEAT How much of the attic is warm

1 = All

2 = Part

0 = None

ATTIC Home has attic

1 = Yes

0 = No

ATTICFIN Part of the attic finished 

1 = Yes

0 = No

9 = Legitimate Skip

BASECOOL Basement air conditioned during summer months

1 = Yes

0 = No

9 = Legitimate Skip

BASEFIN Is the basement finished 

1 = Yes

0 = No

9 = Legitimate Skip

BASEHEAT Basement/crawl Space heated

1 = All

2 = Part

0 = None

9 = 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

CATHCEIL Any cathedral ceilings 

1 = Yes

0 = No

9 = Legitimate Skip

CD65 Number of degree days

CELLAR Home has a basement

1 = Yes

0 = No

9 = Legitimate Skip
7-D-7

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

CRAWL Home has a crawl space

1 = Yes

0 = No

9 = Legitimate Skip

CWASHER Use a clothes washer in home? 

1 = Yes

0 = No

DISHWASH Use an automatic dishwasher in home?

1 = Yes

0 = No

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
7-D-8

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

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
7-D-9

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

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

LPGAUX Secondary heating fuel - LPG 

1 = Yes

0 = No

LPGPAY Who pays for bottled gas

1 = Household pays

2 = Rent/Fee

3 = Other

9 = Legitimate Skip

LRGSTATE Large state designation

0 = Other

1 = New York State

2 = California

3 = Texas

4 = Florida

NAPTFLRS Number of floors in apartment

9 = Legitimate skip
7-D-10

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

PRKGPLC1 Home has Garage or Carport

1 = Yes

0 = No

9 = Legitimate Skip

REGIONC Census region

1 = Northeast 

2 = Midwest 

3 = South 

4 = West 

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

TEMPGONE Day temp when someone home (40-94 degrees Fahrenheit)

95 = Heat turned off

96 = Don't know

97 = Did not live in unit last winter

99 = Legitimate Skip

TEMPGONEAC Day temp when no one home (40-94 degrees Fahrenheit)

95 = AC turned off

96 = Don't know

97 = Did not live in unit last winter

99 = Legitimate Skip

TEMPHOME Day temp when someone home (40-94 degrees Fahrenheit)

95 = Heat turned off

96 = Don't know

97 = Did not live in unit last winter

99 = Legitimate Skip
7-D-11

TEMPHOMEAC Day temp when someone home (40-94 degrees Fahrenheit)

95 = AC turned off

96 = Don't know

97 = Did not live in unit last winter

99 = Legitimate Skip

TEMPNITE Sleeping hours temp (40-94 degrees Fahrenheit)

95 = Heat turned off

96 = Don't know

97 = Did not live in unit last winter

99 = Legitimate Skip

TEMPNITEAC Sleeping hours temp (40-94 degrees Fahrenheit)

95 = AC turned off

96 = Don't know

97 = Did not live in unit last winter

99 = Legitimate Skip

TOTATTCSQFT Total Attic number of square feet (0-9999)

TOTBASESQFT Total Basement number of square feet (0-9999)

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

TOTGARGSQFT Total garage number of square feet (0-9999)

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

TOTRHMSQFT Total all other areas 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

UGASHERE Natural gas from underground pipe available 

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

USENG HH uses utility gas 

1 = Yes

0 = No
7-D-12

WALLTYPE Exterior Wall Construction Material 

1 = Brick

2 = Wood

3 = Siding (alum, vinyl, steel)

4 = Stucco

5 = Composition (shingle)

6 = Stone

7 = Concrete or concrete block

8 = Glass

9 = Other

10 = Indescribable 

WARMAIR Sec Ht Eqp Central warm-air furnace with ducts 

1 = Yes

2 = No

9 = Legitimate skip

WELLPUMP Electric pump for well water

1 = Yes

0 = No

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
7-D-13

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-D-14

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>