A PRIL 2006

S PARE THE A I R T ONIGHT S TUDY

2005-2006 WINTER WOOD SMOKE SEASON

C ONDUCTED FOR THE
THIS PAGE INTENTIONALLY LEFT BLANK 
Table of Contents

Winter Spare the Air Tonight Study BAAQMD © 2006 i . . . . . . . . . . . . . . . .

T ABLE O F C ONTENTS

Table of Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

List of Figures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Motivation for Study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Overview of Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Organization of Report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Just the Facts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Wood Burning Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Changes in Wood Burning Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Recall and Awareness of Spare the Air Tonight Messaging . . . . . . . . . . . . . . . . . . . . . . . . . 5

Attitudes About Wood Smoke. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Changing Heating Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Perceptions of Entities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Wood Burning Behavior. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Heating Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Question 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Fuel Type & Source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Question 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Question 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Question 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Question 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Primary Reason for Burning Wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Question 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Use of Fireplace, Wood Stove or Pellet Stove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Question 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Question 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Seasonal Wood Burning Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Question 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Question 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Question 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Wood Burning Behavior in Past Week . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Question 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Question 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Duration & Volume of Wood Burning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Question 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Question 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Non-Winter Wood Burning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Question D1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Changes in Wood Burning Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Changes in Wood Burning Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Question 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Question 17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Changes Among Those who Increased Burning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Question 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Question 19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Question 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Reductions in Wood Burning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Question 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
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Question 22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Campaign Impacts on Wood Burning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Recall and Awareness of Spare the Air Tonight Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Recall Exposure to Spare the Air Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Question 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Information Source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Question 25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Attitudes about Wood Smoke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Question 27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Question 28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Wood Smoke a Neighborhood Problem? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Question 29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Question 30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Changing Heating Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Question 31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Willingness to Change Heating Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Question 32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Question 33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Question 34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Recall News Story, Advertisement or Announcement? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Question 35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Question 36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Policy Attitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Question 37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Question 38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Question 39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Perceptions of Entities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Awareness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Question 40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Opinions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Question 41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Exposure to Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Question 42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Background & Demographics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Questionnaire. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

CATI & Pre-Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Sample & Weighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Margin of Error. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Data Collection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Rounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Questionnaire & Toplines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
List of Tables

iii . . . . . . . . . . . . . . . . Winter Spare the Air Tonight Study BAAQMD © 2006

L IST O F T ABLES

Table 1 Frequency of Burning Wood this Winter by Study Year (n = 864) . . . . . . . . . . . . . . . . 20

Table 2 Burned Wood in Past Seven Days by Study Year (n = 864) . . . . . . . . . . . . . . . . . . . . . 21

Table 3 Wood Burning on Non-winter Months by Heating Device in Home . . . . . . . . . . . . . . . 26

Table 4 Frequency of Wood Burning Among Those Burning More Often Because of Increased 

 Energy Costs (n = 89) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 5 Spare the Air Reducers: Confidence Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 6 Background and Demographics (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 7 Completed Interviews by County (Unweighted) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Table 8 Interview Dates (Unweighted) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
List of Figures

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L IST O F F IGURES

Figure 1 Types of Heating Devices in Home by Study Year (n = 2,625). . . . . . . . . . . . . . . . . . . 9

Figure 2 Types of Heating Devices in Home by County (n = 2,625) . . . . . . . . . . . . . . . . . . . . 10

Figure 3 At Least One Heating Device in Home by County (n = 2,625) . . . . . . . . . . . . . . . . . . 10

Figure 4 At Least One Heating Device in Home by Home Type & Age of Home in Years 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 5 Type of Fuel Burned (n = 1,547) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 6 Type of Wood Burned (n = 813) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 7 Type of Wood Burned by Expected Frequency of Winter Wood Burning (n = 813) . . . 13

Figure 8 Wood Source (n = 813) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 9 Wood Source by Expected Frequency of Winter Wood Burning (n = 813) . . . . . . . . . 14

Figure 10 Status of Wood Typically Burned (n = 813). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 11 Status of Wood Typically Burned by Expected Frequency of Winter Wood Burning 

 (n = 813). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 12 Primary Purpose of Wood Burning (n = 813). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 13 Primary Purpose of Wood Burning by Expected Frequency of Winter Wood Burning 

 (n = 813). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 14 Heating Device Usage this Winter by Study Year (Fireplace: n = 1,547; 

 Pellet Stove: n = 170; Wood stove: n = 165) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 15 Household Heating Device Usage this Winter by County (n = 2,625) . . . . . . . . . . . 17

Figure 16 Reason for Not Using Heating Device this Winter (Fireplace: n = 581; 

 Pellet Stove: n = 42; Woodstove: n = 35) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 17 Heating Device Households Not Burning Because of Air Quality Reasons 

 (n = 1,679) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 18 Frequency of Burning Wood this Winter (n = 864) . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 19 Frequency of Burning Wood this Winter Among All Heating Device Households 

 by County (n = 1,679) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 20 Burned Wood in Past Seven Days (n = 864) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 21 Heating Device Households that Burned Wood in Past Seven Days by County 

 (n = 1,679) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 22 Heating Device Households that Burned Wood Yesterday / Last Night by County 

 (n = 1,679) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 23 Heating Device Households that Burned Wood Yesterday / Last Night by Day Type, 

 Precipitation on Day Prior to Interview & Low Temperature on Day Prior to Interview 

 (n = 1,679) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 24 Hours of Burning in Typical Day of Wood Burning (n = 864). . . . . . . . . . . . . . . . . . 24

Figure 25 Distribution and Average Hours of Burning in Typical Day of Wood Burning by 

 County & Expected Frequency of Winter Wood Burning (n = 864) . . . . . . . . . . . . . 24

Figure 26 Logs Burned in Typical Day of Wood Burning (n = 864) . . . . . . . . . . . . . . . . . . . . . 25

Figure 27 Logs Burned in Typical Day of Wood Burning by County & Expected Frequency of 

 Winter Wood Burning (n = 864) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 28 Expected Frequency of Wood Burning this Winter Compared to Last Winter and 

 Reasons for Burning More Often (n = 864) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 29 Frequency of Wood Burning Last Winter Among Those Burning More Often Because 

 of Increased Energy Costs (n = 89) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 30 Chose not to Burn this Winter (n = 864). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 31 Spare the Air Reducers by Study Year & County Showing Confidence Intervals 

 (n = 1,679) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 32 Heard, Read, or Saw Spare the Air Winter Information by Study Year (n = 2,625) . . 32

Figure 33 Heard, Read, or Saw Spare the Air Winter Information by County (n = 2,625) . . . . . 33

Figure 34 Heard, Read, or Saw Spare the Air Winter Information by Age & Household Income 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 35 Source for Spare the Air Winter Information (n = 891) . . . . . . . . . . . . . . . . . . . . . . 34
List of Figures

Winter Spare the Air Tonight Study BAAQMD © 2006 . . . . . . . . . . . . . . . . v

Figure 36 Perceive Negative Health Effects are Associated with Wood Smoke by Study Year 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 37 Perceive Negative Health Effects are Associated with Wood Smoke by County 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 38 Perceive Negative Health Effects are Associated with Wood Smoke by Age 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 39 Perceived Negative Effects of Breathing Wood Smoke (n = 1,730) . . . . . . . . . . . . . 37

Figure 40 Perception of Periodic Wood Smoke Problem in Neighborhood (n = 2,625) . . . . . . 38

Figure 41 Perception of Wood Smoke Problem in Neighborhood by Study Year & County 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Figure 42 Woodstove or Pellet Stove EPA Certified by Study Year (n = 328) . . . . . . . . . . . . . . 40

Figure 43 Willingness to Replace Fireplace or Stove with EPA Certified Model (n = 913) . . . . . 41

Figure 44 Willingness to Replace Fireplace or Stove with EPA Certified Model by County 

 (n = 913). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Figure 45 Willingness to Replace Fireplace or Stove with EPA Certified Model by Age 

 (n = 913). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Figure 46 Willingness to Participate in Government-Sponsored Rebate Program (n = 511) . . . 43

Figure 47 Santa Clara County Program Awareness by Study Year (n = 637) . . . . . . . . . . . . . . 44

Figure 48 Marin County Program Awareness by Study Year (n = 109) . . . . . . . . . . . . . . . . . . 45

Figure 49 Support for Proposed Policy Changes (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . 46

Figure 50 Support for Proposed EPA Certification Requirements in New Housing 

 Construction by Study YEar (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Figure 51 Support for Proposed Policy Changes by County (n = 2,625) . . . . . . . . . . . . . . . . . 47

Figure 52 Support for Proposed Policy Changes by Age (n = 2,625). . . . . . . . . . . . . . . . . . . . 48

Figure 53 Support for Proposed Policy Changes by Household Income & Home Type 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Figure 54 Awareness of BAAQMD & Spare the Air Tonight Campaign by Study Year 

 (n = 2,625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Figure 55 Awareness of BAAQMD & Spare the Air Tonight Campaign by County (n = 2,625) . 50

Figure 56 Opinions of BAAQMD & Spare the Air Campaign by Study Year 

 (BAAQMD: n = 1,466; STA Tonight Campaign: n = 1,218) . . . . . . . . . . . . . . . . . . . 51

Figure 57 Encountered Info about BAAQMD & Spare the Air Tonight Campaign in Past Six 

 Months by Study Year (BAAQMD: n = 1,466; STA Tonight Campaign: n = 1,218) . . 52

Figure 58 Encountered Info about BAAQMD & Spare the Air Tonight Campaign in Past Six 

 Months by County (n = 2,625). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Figure 59 Encountered Info about BAAQMD & Spare the Air Tonight Campaign in Past Six 

 Months by Heating Device in Home & Age (n = 2,625). . . . . . . . . . . . . . . . . . . . . . 53

Figure 60 Maximum Margin of Error Plot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Introduction

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I NTRODUCTION

The Bay Area Air Quality Management District (BAAQMD) was established in 1955 by the California State Legislature as the first multi-county agency in the State to address the problem of air

pollution on a regular basis. The BAAQMD’s primary regulatory authority covers stationary

sources of air pollution such as factories, industrial facilities, manufacturing operations, gasoline stations and dry cleaners. The BAAQMD is also responsible for transportation control measures to reduce emissions from mobile sources of air pollution in its Clean Air Plan. 

Serving the counties of Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa

Clara, and the western half of Solano and southern half of Sonoma, one of the BAAQMD’s primary charges is to increase public awareness of positive air quality choices. To facilitate this

effort, the Spare the Air Program was established by the BAAQMD in 1991 to educate residents

about air pollution and to encourage them to modify their behavior to reduce and prevent it.

During the summer ozone season (May to October), the BAAQMD conducts episodic public education campaigns designed to encourage the public to reduce their driving and use of certain

household products on days that are expected to violate ozone air quality standards. During the

winter season (November to February), the focus of the Program shifts to reducing the impact of

wood burning on air quality by encouraging the public to not burn wood and to replace their

wood burning fireplaces and stoves with cleaner alternatives, such as natural gas fireplaces. 

Although today many air quality management districts throughout the country administer similar

programs, the Spare the Air program in the Bay Area was the first of its kind.

MOTIVATION FOR STUDY The primary motivation for this study was to better understand the public’s attitudes and behavior with respect to burning wood, their awareness of the

Spare the Air Tonight Program, as well as the impact that the Program has had on awareness,

opinions and behavior relevant to burning wood and air quality. In this respect, this study is

quite similar to past surveys conducted for the BAAQMD in 2001, 2002, 2003 and 2004.

The passage of California Senate Bill 656 to reduce public exposure to particulate matter (PM10

and PM2.5) was another key motivation for the 2005 study.1 SB 656 requires the California Air

Resources Board (ARB), in consultation with local air districts, to develop and adopt a list of the

most readily available, feasible and cost-effective control measures that could be used to reduce

PM10 and PM2.5 -- with the goal of making progress in the near-term toward attainment of State

and Federal PM10 and PM2.5 standards. Although the Bay Area is currently in attainment for the

Federal PM10 and PM2.5 standards, like almost every other area in California it does not meet

the stricter State standards.

1. Particulate matter (PM) consists of very small liquid and solid particles suspended in the air, and includes 

particles smaller than 10 microns (PM10) as well as finer particles smaller than 2.5 microns (PM2.5). Ambient 

PM is made up of particles that are emitted directly -- such as soot and fugitive dust -- as well as secondary 

particles that are formed in the atmosphere from reactions involving precursor pollutants such as oxides of 

nitrogen, sulfer oxides, volatile organic compounds, and ammonia. Exposure to PM is linked to increased 

frequency and severity of asthma attacks and even premature death in people with pre-existing cardiac or 

respiratory disease. Infants and children, the elderly, and persons with heart and lung disease are the most 

sensitive to PM pollution. For more on particulate matter, SB 656 and the BAAQMD’s implementation schedule, see the Particulate Matter Implementation Schedule staff report prepared by the Planning and Research 

Division of the BAAQMD, November 9, 2005.
Introduction

Winter Spare the Air Tonight Study BAAQMD © 2006

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With a greater emphasis placed on reducing particulate matter in the Bay Area, the 2005 study

presented a good opportunity to develop an updated profile of wood burning behavior in the Bay

Area that would allow for statistically reliable estimates within each of the nine member counties. The most recent inventory prior to this study was conducted in 1988.2

OVERVIEW OF METHODOLOGY A full description of the methodology used for this

study is included later in this report (see Methodology on page 55). A total of 2,625 randomly

selected residents within the District’s boundaries participated in a telephone survey on one of

twenty-eight interviewing dates between November 22, 2005 and February 17, 2006. Probabilitybased sampling techniques and monitoring of the demographics resulted in a sample that is representative of the adult population within the District.

To accommodate the District’s interest in obtaining statistically reliable estimates within each of

the nine member counties, as well as to explore the relationship between both weather and special events on wood burning behavior, the study employed a sampling strategy that involved

stratification by county, month, and day type with strategic oversampling for select counties and

day types. To adjust for the oversampling, the raw data were then weighted by day type and

adult population estimates by county prior to analyses and presentation. The results presented

in this report are the weighted results, which are representative at the District-wide level, as well

as within the nine member counties.

When compared to the past surveys conducted for the District on wood burning and the Spare

the Air Tonight Program, there are several methodological changes worth noting at the outset of

this report. The most obvious difference is the substantially larger sample size (2,625) employed

in this study when compared to past efforts, which improves the statistical reliability of the

results. In the interest of improving the validity and reliability of select opinion and behavior

measures, the 2005 study continued several questionnaire changes that were first implemented

in the 2004 season. The most notable of these changes addressed how the questionnaire measured the impacts of the Spare the Air Tonight Program. The changes were made so that the

impacts of the winter program on wood burning behavior would be measured using the same

basic methodology employed by the BAAQMD -- and recommended by CARB and EPA3 -- to measure the impacts of the summer Spare the Air Program on driving behavior.4

Based on the 2004 results, several additional refinements were made to the 2005 questionnaire

with respect to measuring wood burning behavior. Because these improvements often involved

changing the wording, format and/or response options for a particular question, it is not possi2. The California Residential Wood Consumption Survey. Report prepared by Northern California Research 

Associates for the California Air Resources Board, 1988.

3. The CARB/EPA Method is summarized in the Transportation Research Board’s (TRB) journal --Transportation 

Research Record -- for 2004 in an article entitled Development of a Quantification Method for Measuring the 

Travel and Emissions Impacts of Episodic Ozone Alert Programs (pages 153-159). It is described in detail in 

the following air resources guidance report: CARB, “Quantification Method Reference Manual: A Method to 

Measure Travel and Emissions Impacts of Ozone Action Public Education Programs,” April 2003. In addition 

to Eric Schreffler, Dr. Timothy McLarney and Richard Sarles, the TRB paper and guidance report were coauthored by Joann Lu and Jeff Weir of CARB, as well as Thomas Higgins and Dr. Will Johnson of K.T. Analytics.

4. For a detailed description of the updated CARB/EPA Method and its application to the BAAQMD’s summer 

Spare the Air Program, see the Spare the Air Study: 2005 Summer Ozone Season report prepared for the 

BAAQMD by True North & ESTC.
Introduction

Winter Spare the Air Tonight Study BAAQMD © 2006

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ble to statistically compare the results of the 2005 survey with previous surveys for select measures. Where such comparisons are possible, however, this report presents the results from past

surveys.

ORGANIZATION OF REPORT This report is designed to meet the needs of readers who

prefer a summary of the findings, as well as those who are interested in the details of the results.

For those who seek an overview of the findings, the sections titled Just the Facts and Conclusions

are for you. They provide a summary of the most important factual findings of the survey in bullet-point format and a discussion of their implications. For the interested reader, this section is

followed by a more detailed question-by-question discussion of the results from the survey by

topic area (see Table of Contents), as well as a description of the methodology employed for collecting and analyzing the data. And, for the truly ambitious reader, the questionnaire used for

the interviews is contained at the back of this report, and a complete set of crosstabulations for

the survey results is contained in Appendix A.

ACKNOWLEDGEMENTS True North would like to thank Emily Hopkins and Dr. David

Fairely of the BAAQMD, as well as Eric Schreffler of ESTC, for their valuable input during the

design and reporting stages of this study. Their expertise and insight improved the overall quality of the research presented here.

DISCLAIMER The statements and conclusions in this report are those of the authors,

Dr. Timothy McLarney and Richard Sarles at True North Research, Inc. (True North), and not necessarily those of the BAAQMD. Any errors or omissions are the responsibility of the authors.
Just the Facts

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J UST THE F ACTS

The following is an outline of the main factual findings from the 2005 study. For the reader’s

convenience, we have organized the findings according to the section titles used in the body of

this report. Thus, to learn more about a particular finding and how it may compare to findings

from prior surveys (where applicable), simply turn to the appropriate report section.

WOOD BURNING BEHAVIOR 

• Sixty-four percent (64%) of households in the District contain at least one fireplace, pellet 

stove or wood stove.

• Among households with a fireplace, the type of fuel most commonly used is wood (48%), followed by natural gas (16%) and manufactured logs such as a Duraflame or Presto (10%).

• Among wood-burning households, oak was the most commonly mentioned (39%) type of

wood burned. Approximately 38% of households were unable to identify the type of wood

that they burn.

• When asked how they typically acquire their wood, respondents were split between those

who gather their own (35%), those who purchase the wood from a local store (32%), those

who rely on a wood supplier (22%), those who use an alternative source (7%), and those who

were unsure (4%).

• The vast majority (85%) of households that burn wood indicated that they burn dry, seasoned wood as opposed to fresh-cut, moist wood (5%). Approximately 10% were unsure as

to the status of the wood that they burn.

• Half (50%) of all households that burn wood indicated that they primarily do so for ambiance rather than heat.

• Households that contain a wood stove were the most likely (74%) to report that they would

use the stove during the winter months of November through February. The rate of

expected use for pellet stoves and fireplaces was 72% and 60%, respectively.

• Approximately 8% of respondents who reported that they would not use their fireplace this

winter indicated that were refraining from using the device for air quality reasons. An additional 8% referenced a health-related reason for not using their fireplace.

• Approximately half (49%) of households that expected to burn wood this winter anticipated

doing so on a weekly basis.

• Forty-three percent (43%) of households with at least one fireplace, wood stove or pellet

stove that expected to burn wood this winter indicated that they had burned wood in the

week prior to the interview.

• Twenty-two percent (22%) of households with at least one fireplace, wood stove or pellet

stove that expected to burn wood this winter indicated that they had burned wood on the

day prior to the interview.

• On a typical burn day, wood-burning households averaged 3.8 hours of burning time.

• On a typical burn day, wood-burning households consumed an average 5.12 logs.

• Seventeen percent (17%) of all households indicated that they burn wood in a least one nonwinter month.
Just the Facts

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CHANGES IN WOOD BURNING BEHAVIOR 

• Overall, 56% of households that own a wood-burning heating device and expected to burn

wood this season reported that they anticipated burning wood at about the same frequency

this season as last.

• Among the 22% of households that expected to burn more frequently this winter when compared to last, approximately half stated that they were burning more often due to the high

cost of energy/gas.

• Twenty-nine percent (29%) of respondents who have a fireplace, wood stove and/or pellet

stove and expected to burn wood during the 2005-2006 winter season indicated that -- on

at least one occasion -- they refrained from burning wood. 

• When asked why they chose not to burn wood on these occasions, 1% specifically mentioned

the Spare the Air Tonight Campaign and an additional 3% offered an air quality or healthrelated reason.

• Approximately 2% of adults who live in a household with at least one fireplace, wood stove

or pellet stove reduced the amount of wood they burned during the 2005-2006 winter season in response to the Spare the Air Tonight Campaign.

RECALL AND AWARENESS OF SPARE THE AIR TONIGHT MESSAGING 

• Overall, 34% of adults in the Bay Area recalled being exposed to news stories, advertisements or public service announcements related to the Spare the Air Tonight Program during 

the three months prior to the interview.

• When asked to indicate where they obtained the information about the Spare the Air Tonight

Program, the most commonly cited sources were television (45%) and radio (38%).

ATTITUDES ABOUT WOOD SMOKE 

• Approximately two-thirds (66%) of Bay Area adults perceive that there are negative health 

effects associated with breathing wood smoke.

• When asked in an open-ended manner to identify some of the specific negative health

effects associated with breathing wood smoke, most respondents focused on lung disease

in general (36%) or made a specific reference to asthma (24%).

• Eighteen percent (18%) of Bay Area adults perceive that their neighborhood periodically 

experiences air pollution from wood smoke. Twelve percent (12%) stated that the problem 

was a small one, 4% indicated it was a moderate or medium problem, and 1% felt that air 

pollution due to wood smoke was a big problem in their neighborhood.

CHANGING HEATING DEVICE 

• Among individuals who own a wood stove or a pellet stove, 59% indicated that their stove is 

EPA certified.

• Twenty-eight percent (28%) of respondents who owned a wood burning fireplace and/or

non-EPA certified wood stove or pellet stove were willing to replace their current device --

without a financial incentive -- with a gas fireplace.

• Thirty-four percent (34%) of respondents who owned a wood burning fireplace and/or nonEPA certified wood stove or pellet stove were willing to replace their current device -- without

a financial incentive -- with an EPA certified wood stove or pellet stove.
Just the Facts

Winter Spare the Air Tonight Study BAAQMD © 2006

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• Ten percent (10%) of those who were initially unwilling to replace their current heating

device for a cleaner alternative in the absence of a financial incentive were willing to do so if

a $200 rebate were offered. As the amount of the rebate increased to $300, $400 and $500,

the proportion of these individuals who would participate in the rebate program increased

to 13%, 16% and 23%, respectively.

• Just 6% of Santa Clara County residents -- and 4% of Marin County residents -- could recall

hearing, reading or seeing a news story, advertisement or public service announcement

about the rebate programs offered by the respective counties.

• Sixty-one percent (61%) of Bay Area adults support a policy that would require all new housing construction to use only gas fireplaces or EPA certified fireplace inserts, wood stoves or

pellet stoves.

• Seventy-four percent (74%) of Bay Area adults support a policy that would prohibit wood

burning on nights when air pollution is expected to reach unhealthy levels.

• Half (50%) of Bay Area adults support a policy that would require older wood stoves to be

removed or replaced with a cleaner burning model when a home is sold to a new owner.

PERCEPTIONS OF ENTITIES 

• Prior to taking the survey, 56% of respondents had heard of the Bay Area Air Quality Management District and 46% had heard of the Spare the Air Tonight Program.

• Among respondents who had heard of the BAAQMD, half (51%) held a favorable opinion of

the agency, whereas 41% held a neutral opinion or weren’t sure of their opinion, and just 8%

held an unfavorable opinion.

• Among respondents who had heard of the Spare the Air Tonight Program, 64% held a favorable opinion of the Program, whereas 30% held a neutral opinion or weren’t sure of their

opinion, and 5% held an unfavorable opinion.

• Thirty-five percent (35%) of respondents recalled hearing, reading or seeing a news story,

advertisement or public service announcement in the six months prior to taking the interview that pertained to the BAAQMD. The corresponding figure for the Spare the Air Tonight

campaign was 43%.
Conclusions

Winter Spare the Air Tonight Study BAAQMD © 2006

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C ONCLUSIONS

As noted in the Introduction, this study was designed to provide a better understanding of the

public’s attitudes and behavior with respect to burning wood, their awareness of the Spare the

Air Tonight Program, as well as the impact that the Program has had on awareness, opinions and

behavior relevant to wood burning and air quality. Whereas subsequent sections of this report

are devoted to conveying the detailed results of the study, in this section we attempt to ‘see the

forest through the trees’ and note how the collective results answer some of the key questions

that motivated the research.

What is the profile of 

wood burning behavior 

in the Bay Area?

Overall, nearly two-thirds (64%) of households in the Bay Area own at

least one fireplace, wood stove or pellet stove, and one-third (33%)

burned wood in the 2005-2006 winter months. Although the type of

wood burned varies considerably, as does the source from which the

wood is obtained, the vast majority (85%) of households report that they

burn dry, seasoned wood.

Wood burning behavior varies considerably depending on how frequently a household burns. Wood-burning households can easily be

divided between the 49% that burn at least once per week (frequent

burners) and those that burn less often (infrequent burners). Not only do

frequent burners build fires more often, then tend to burn significantly

more hours per burn day (4.63 hours on average) and consume more

wood per burn day (6.28 logs on average) when compared to infrequent

burners. Their reasons for burning wood are also different. Whereas frequent burners primarily build fires for heat, infrequent burners primarily

build fires for ambiance.

Wood burning behavior also varies considerably across the nine-county

District. In the predominately rural counties of Marin, Sonoma, Solano

and Napa, the proportion of households with a heating device that burn

wood at least once per week is substantially greater than in the rest of

the District. For example, whereas 43% of Sonoma County households

with a heating device burn wood at least once per week, the corresponding figure for San Francisco County is just 21%. For more information

about wood burning behavior in the Bay Area, see Wood Burning Behavior on page 9.

How effective was the 

Spare the Air Tonight 

Campaign during the 

2005-2006 winter?

The Spare the Air Tonight Campaign seeks to shape public awareness

and opinions about the District and air quality issues, as well as change

behavior with respect to burning wood. Accordingly, the survey sought

to measure the impacts that the campaign had on each of these dimensions.

In terms of attitudes and awareness, by most measures the 2005-2006

campaign was a success. Awareness of the BAAQMD and the Spare the

Air Tonight Program was widespread among Bay Area adults. Moreover,
Conclusions

Winter Spare the Air Tonight Study BAAQMD © 2006

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opinions about the BAAQMD and the Spare the Air Tonight Program were

much more favorable in 2005 and 2004 when compared to the 2003

winter season. With respect to attitudes about wood smoke, the Program

has succeeded in raising public recognition of the negative health

impacts of breathing wood smoke by 17% since 2002. 

The increased awareness of the health-related problems caused by wood

smoke arguably underpins what is broad support for the adoption of

new policies designed to improve the air quality in the region. Nearly

two-thirds of adults favor requiring all new housing construction to use

only gas fireplaces or EPA certified fireplace inserts, wood stoves or pellet stoves, and three-quarters (74%) favor prohibiting wood burning on

evenings when air pollution is forecast to reach unhealthy levels.

So how did these positive changes in attitudes and awareness translate

to actual changes in wood burning behavior? Based on the survey data, it

is estimated that 2% of adults who live in a household with at least one

fireplace, wood stove or pellet stove reduced the amount of wood they

burned during the 2005-2006 winter season in direct response to the

Spare the Air Tonight Campaign.5 Some respondents refrained from

burning wood the entire season for air quality or health-related reasons,

whereas those who did burn wood reported that they refrained from

burning wood on an average 2.5 occasions during the season in

response to the campaign. 

Are there any opportunities that the Program 

can take advantage of to 

be more successful in 

the future?

The survey results suggest a clear opportunity for the Program to further

reduce air pollution due to wood smoke by helping to establish and promote rebate programs for the replacement of traditional fireplaces and

non-EPA certified wood stoves and pellet stoves. Approximately 38% of

respondents who owned a traditional fireplace and/or a non-EPA certified wood stove or pellet stove indicated that they were willing to replace

the device if offered a modest incentive ($200), yet only two counties

(Santa Clara and Marin) currently offer such a rebate program and public

awareness of these existing programs is poor. 

Helping to increase the awareness of the existing programs would be a

natural first step in gauging the effectiveness of this approach to reducing air pollution due to wood smoke. Raising the amount of the rebate

could also be expected to significantly increase the percentage of households that participate in the Program. If the promotion of the existing

programs is determined to substantially increase participation in the programs, it would make sense to invest in establishing and promoting similar programs in the remaining Bay Area counties.

5. Stated differently, 36,547 households out of the estimated 1,555,185 household with at least one fireplace, 

wood stove or pellet stove refrained from burning wood on at least one occasion in response to the Spare 

the Air Tonight Campaign.
Wood Burning Behavior

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W OOD B URNING B EHAVIOR

One of the key objectives of the survey was to profile respondents’ use of wood burning heating

devices, including fireplaces, pellet stoves and wood stoves. Accordingly, the first series of questions in the survey asked respondents about the types of wood burning heating devices they

have in their home, as well as their use of these devices during the 2005-2006 winter months of

November through February.

HEATING DEVICES The first question in this series simply asked respondents to identify

how many fireplaces, wood stoves and pellet stoves their household contains. As shown in

Figure 1, 59% of households contain at least one fireplace, 7% contain at least one pellet stove,

and 6% contain at least one wood stove. Collectively, 64% of respondents reported that their

household contained at least one fireplace, pellet stove or wood stove, whereas 36% of respondents indicated that their household does not contain a fireplace, pellet stove or wood stove.6

For reference, the results from the 2004 survey are also shown in Figure 1.

Question 1 Do you have a: _____ in your home? If yes, ask: How many: _____s do you have in

your home?

FIGURE 1 TYPES OF HEATING DEVICES IN HOME BY STUDY YEAR (N = 2,625)7

6. Because some households contained more than one type of heating device -- e.g., a fireplace and a wood 

stove -- one can not simply add the percentages shown in Figure 1 to determine the percentage of households that have at least one type of heating device.

One

50.5

One

4.7

One

4.9

Two

7.4

One - 5.8 One - 5.6

One

50.4

Two

8.9

Three or more

1.0

0

10

20

30

40

50

60

70

Fireplace Pellet stove Woodstove Fireplace Pellet stove Woodstove

2005 2004

Study Year

% Households

59.0

6.5 6.3

61.6

5.6 5.4
Wood Burning Behavior

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For the interested reader, the following figures show how the presence of fireplaces, wood

stoves and pellet stoves varied by county (see Figures 2 and 3), home type, and age of home (see

Figure 4).

FIGURE 2 TYPES OF HEATING DEVICES IN HOME BY COUNTY (N = 2,625)

FIGURE 3 AT LEAST ONE HEATING DEVICE IN HOME BY COUNTY (N = 2,625)

7. The n = 2,625 refers to the number of respondents who received this question. This convention will be followed throughout the report to allow the reader to identify how many respondents are included in each figure.

55.8

62.5

54.0

61.2

67.0

5.8 6.4

8.9

4.2 3.8 2.9

8.9

4.2

6.7 5.8

2.6

7.0

14.2

21.5

7.0

2.7

9.7

4.7

60.6

45.0

68.8

63.8

0

10

20

30

40

50

60

70

80

90

100

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra Costa

County

% Households

Fireplace Pellet Stove Woodstove

70.9

65.0

58.7

67.3

70.7

65.1

48.5

73.3 73.8

0

10

20

30

40

50

60

70

80

90

100

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Households with Heating Device
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 11

FIGURE 4 AT LEAST ONE HEATING DEVICE IN HOME BY HOME TYPE & AGE OF HOME IN YEARS (N = 2,625)

FUEL TYPE & SOURCE For the 59% of respondents who reported that their household contains a fireplace, the survey next inquired as to the type of fuel that they primarily use in the fireplace (see Figure 5). The most commonly used fuel was wood (48%), followed by natural gas

(16%), and artificial logs such as a Duraflame (6%), Presto (2%) or other manufactured log (2%).8

Approximately 21% of respondents volunteered that they never use their fireplace.

Households with fireplaces that primarily burn wood, as well as households with wood stoves,

were next asked a series of questions about the type of wood they burn (Question 3), from where

they purchase their wood (Question 4), as well as their primary reason for burning wood (Question 5). As shown in Figure 6, 38% of respondents were unable to identify the type of wood that

they burn. Of the specific woods mentioned, oak was the most common (39%), followed by pine/

cedar (10%), almond (4%), and eucalyptus (3%). The ability to identify the type of wood burned

was related to the frequency of burning, with those who burn at least once per week being less

likely than their counterparts to be uncertain as to the type of wood that they burn (see Figure 7).

Nevertheless, regardless of frequency, oak was the most commonly mentioned type of wood.

8. Note that some respondents initially identified their manufactured logs as ‘wood’ in Question 2, but subsequently clarified that they used manufactured logs in Question 3. Their responses to Question 2 were appropriately adjusted prior to analysis.

16.4

64.0

72.8

67.4 65.2

69.6

66.0

83.0

60.8 62.6

16.7

0

10

20

30

40

50

60

70

80

90

100

Apartment Condo Townhome Detached Mobile

home

0 to 10 11 to 20 21 to 30 31 to 40 41 to 50 Over 50

Home Type Age of Home in Years

% Households with Heating Device
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 12

Question 2 What type of fuel do you primarily use in your fireplace - Wood, natural gas, propane, or some other fuel?

FIGURE 5 TYPE OF FUEL BURNED (N = 1,547)

Question 3 What type of wood do you typically burn?

FIGURE 6 TYPE OF WOOD BURNED (N = 813)

0.1

0.1

0.3

0.6

0.7

0.8

1.6

2.4

3.1

15.8

21.0

47.7

5.9

0 10 20 30 40 50 60

Other

Wood + Gas

Pellets

Propane

Electric

Scrap wood

Presto log

Other manufactured log

Not sure

Duraflame log

Natural gas

Never use fireplace

Wood

% Households with Fireplace

0.3

0.4

0.5

0.8

0.8

1.3

2.3

3.1

3.5

38.0

38.7

9.5

0 10 20 30 40 50

Fir

Other

Ash

Hardwood (general)

Fruitwood (general)

Walnut

Whatever available / Mixed

Eucalyptus

Almond

Pine (cedar)

Not sure

Oak

% Wood-burning Households (Fireplace or Woodstove)
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 13

FIGURE 7 TYPE OF WOOD BURNED BY EXPECTED FREQUENCY OF WINTER WOOD BURNING (N = 813)

When asked how they typically acquire their wood, respondents were split between those who

gather their own (35%), those who purchase the wood from a local store (32%), and those who

rely on a wood supplier (22%). Seven percent (7%) mentioned an alternative source, and 4% were

unsure of where their household acquires the wood that they burn (see Figure 8). When compared to their respective counterparts, those who burn wood frequently were more likely to

gather their own wood or rely on a wood supplier (see Figure 9).

Question 4 Do you typically purchase your wood from a wood supplier, the local store, or do

you gather your own wood?

FIGURE 8 WOOD SOURCE (N = 813)

0.0

0.8

0.0

0.4

1.2

0.0

0.9

2.0

2.0

37.0

43.9

0.0

0.0

0.6

0.6

0.6

1.9

1.5

1.5

3.7

11.6

35.1

42.8

0.9

0.5

0.7

1.2

0.6

1.5

3.4

5.3

4.2

8.7

43.5

29.6

8.2

0 5 10 15 20 25 30 35 40 45 50

Fir

Other

Ash

Fruitwood (general)

Hardwood (general)

Walnut

Whatever available / Mixed

Eucalyptus

Almond

Pine (cedar)

Oak

Not sure

% Households that Have and Use Wood-burning Device

At least once per week

Less than once per week

Not at all

Expected Frequency of

Winter Wood Burning

Other

7.1

Local store

31.8

Wood supplier

21.7

Not sure

4.1

Gather own

35.3
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 14

FIGURE 9 WOOD SOURCE BY EXPECTED FREQUENCY OF WINTER WOOD BURNING (N = 813)

The survey next inquired as to whether the respondent typically burns dry, seasoned wood or

wood that is fresh-cut and somewhat moist. As shown in Figure 10, 85% of respondents stated

that they burn dry, seasoned wood, 5% reported that they typically burn fresh-cut wood, and 10%

were note sure. Although frequent burners were more likely to know the status of the wood that

they burn, when one compares the responses among those who provided a specific answer to

Question 5 it appears that frequency of wood burning is not related to the status of the wood

burned. That is, infrequent burners were just as likely as frequent burners to burn dry, seasoned

wood (see Figure 11).

Question 5 Do you tend to burn dry, seasoned wood or wood that is fresh-cut and somewhat

moist? 

FIGURE 10 STATUS OF WOOD TYPICALLY BURNED (N = 813)

5.9

13.3

13.9

17.7 15.3

Wood supplier

27.7

42.0

35.4

Local store

21.6

Gather own

44.6

33.5

22.1

Other 4.7

0

10

20

30

40

50

60

70

80

90

100

At least once per week Less than once per week Not at all

Expected Frequency of Winter Wood Burning

% Households that Have and Use Wood-burning Device

Not sure

9.8

Dry, seasoned

84.9

Fresh-cut, moist

5.2
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 15

FIGURE 11 STATUS OF WOOD TYPICALLY BURNED BY EXPECTED FREQUENCY OF WINTER WOOD BURNING (N = 813)

PRIMARY REASON FOR BURNING WOOD Households that have a wood burning heating device and expected to use it during the winter were next asked to indicate the primary reason for why they use the device -- to heat their home, or for the ambiance of having a fire? Figure

12 shows that residents, as a whole, were rather evenly divided between those who primarily

burn for heat (46%) and those who primarily burn for ambiance (50%). As expected, the reason

for using a heating device was related to the frequency of burning. Frequent burners were much

more likely (66%) to indicate that they burn wood for heating purposes, whereas infrequent burners much more likely (69%) to report that they burn for ambiance (see Figure 13).

Question 6 When you use your fireplace or woodstove, which of the following would you say is

the primary reason you do so? For heating your home, or for the ambiance of having a fire

FIGURE 12 PRIMARY PURPOSE OF WOOD BURNING (N = 813)

Dry, seasoned

89.1

75.7

86.6

Fresh-cut, moist

6.5

3.4

5.0 20.8

8.3 Not sure 4.4

0

10

20

30

40

50

60

70

80

90

100

At least once per week Less than once per week Not at all

Expected Frequency of Winter Wood Burning

% Households that Have and Use Wood-burning Device

Ambiance

50.3

Heat

46.1

Not sure

3.6
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 16

FIGURE 13 PRIMARY PURPOSE OF WOOD BURNING BY EXPECTED FREQUENCY OF WINTER WOOD BURNING (N = 813)

USE OF FIREPLACE, WOOD STOVE OR PELLET STOVE Respondents whose household contained at least one fireplace, pellet stove or wood stove were next asked -- for each

device they own -- whether they have or intend to use the device this winter between the months

of November through February. As shown in Figure 14, 74% of households that contain a wood

stove indicated that they would use the device this winter. The rate of use was similar for pellet

stoves (72%) and notably lower for fireplaces (60%). The results for the 2004 survey -- which was

conducted at the end of the season rather than throughout -- are presented for comparison.

Question 7 Will you use your: _____ this winter?

FIGURE 14 HEATING DEVICE USAGE THIS WINTER BY STUDY YEAR (FIREPLACE: N = 1,547; PELLET STOVE: N = 170; 

WOOD STOVE: N = 165)

29.2

35.6

Heat

66.0

69.1 56.0

Ambiance

31.2

Not sure 2.8 8.4

0

10

20

30

40

50

60

70

80

90

100

At least once per week Less than once per week Not at all

Expected Frequency of Winter Wood Burning

% Households that Have and Use Wood-burning Device

56.4

84.2

Yes

59.8 56.1

74.4 71.8

No

37.6 42.5

24.9† 21.4

43.6

15.8

0

10

20

30

40

50

60

70

80

90

100

Use fireplace this

winter

Use pellet stove

this winter

Use woodstove

this winter

Use fireplace this

winter

Use pellet stove

this winter

Use woodstove

this winter

2005 2004

Study Year

% Heating Device Households
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 17

Figure 15 provides a useful summary of the presence and expected use of heating devices for

the District as a whole, as well as by the nine member counties. Overall, 64% of households surveyed in the District contained at least one heating device (fireplace, wood stove or pellet stove),

41% expected to use a heating device this winter, and one-third (33%) expected to use at least

one wood burning heating device this winter. Among the nine counties, households in Marin had

the highest rate of expected heating device use (58%), as well as the highest expected use of

wood burning heating devices (47%). San Francisco County residents reported the lowest rates of

the presence and use of heating devices.

FIGURE 15 HOUSEHOLD HEATING DEVICE USAGE THIS WINTER BY COUNTY (N = 2,625)

Respondents who indicated that they do not expect to use their fireplace, wood stove or pellet

stove this winter in Question 7 were next asked to indicate why they do not intend to use the

device. As shown in Figure 16, approximately 8% of fireplace owners who did not intend to use

the device this winter offered a reason related to air quality and an additional 8% mentioned a

specific health-related reason. Approximately 3% of pellet stove owners and 9% of wood stove

owners who did not intend to use the devices also mentioned air quality as a reason for not

using the device this winter. The remaining respondents offered a reason unrelated to air quality

or health.

For the interested reader, Figure 17 displays the percentage of households that own a fireplace,

wood stove or pellet stove and offered air quality as a reason for why they did not expect to use

the device this winter, by county. San Mateo County had the highest percentage (6%) of device

owning households that fit this description, whereas Sonoma County had the lowest (2%).

73.8

70.9

65.0

58.7

67.3

70.7

42.9

37.9

49.0 46.8

33.2

27.9 27.8

40.2

46.6

40.9

33.9 32.2

39.1

35.7

65.1

48.5

73.3

63.9

52.3

57.8

35.9

32.0

47.4

41.0

0

10

20

30

40

50

60

70

80

90

100

BAAQMD

District

Overall

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Households

At least one heating device in home

Expect to use at least one heating device

Expect to use at least one wood burning heating device
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 18

Question 8 Why do you not expect to use your: _____ this winter?

FIGURE 16 REASON FOR NOT USING HEATING DEVICE THIS WINTER (FIREPLACE: N = 581; PELLET STOVE: N = 42; 

WOODSTOVE: N = 35)

FIGURE 17 HEATING DEVICE HOUSEHOLDS NOT BURNING BECAUSE OF AIR QUALITY REASONS (N = 1,679)

Air quality

8.2

9.4

3.3

Health reasons

8.3

2.8

0

5

10

15

20

Fireplace Pellet stove Woodstove

Q8 Reason for not using . . .

% Households that Do Not Plan to Use a

Particular Heating Device this Winter

Health reasons

Air quality

1.9

2.5 2.5

4.4

2.7 2.6

3.8

6.0

2.2

0

2

4

6

8

10

Santa

Clara

San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Heating Device Households that Mentioned Air Quality as a

Reason for Not Using a Heating Device this Winter
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 19

SEASONAL WOOD BURNING BEHAVIOR The next series of questions were only asked

of respondents who owned at least one fireplace, pellet stove or wood stove and indicated that

they will burn wood during the 2005-2006 winter months.

The first question (Question 9) asked each respondent how often they expected that they would

burn wood this winter -- at least once per week or less often? Respondents who indicated that

they expected to burn wood less often than once per week were next asked to be more specific

as to how often they expected to burn wood -- two to three times per month, once per month, or

less often than once per month? For respondents who indicated that they expected to burn wood

weekly, Question 11 asked how many days they expected to burn wood in a typical winter week.

The results to all three questions are combined in Figure 18.

Overall, nearly half (49%) of respondents indicated that they expected to burn wood on a weekly

basis, although most (31%) stated that they would burn wood three days or less per week. Overall, 19% indicated that they expected to burn wood two to three times per month, 17% once per

month, and 12% expected to burn wood less often than once per month.

Question 9 How often do you expect to burn wood this winter? At least once per week or less

often than that? 

Question 10 Would you say that you will burn wood about two to three times per month, once

per month, or less often than once per month? 

Question 11 In a typical winter week, how many days do you expect to burn wood?

FIGURE 18 FREQUENCY OF BURNING WOOD THIS WINTER (N = 864)

When compared to 2004, there was a statistically significant increase in the percentage of

respondents who indicated that their household would burn wood at least once per week (see

Table 1). Whereas in 2004 just over one-third (34%) expected to burn wood weekly, the percentage in 2005 was much higher at 49%. A portion of this increase is clearly due to the higher cost

At least once

per week

48.9

Once per month

17.0

Not sure

Less than once 4.0

per month

11.7

2 to 3 times per

month

18.5

Seven days

7.2

Six days

0.8

Four days

4.3

One day

9.3

Two days

11.5

Three days

10.4

Five days

3.2

Not sure

2.2
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 20

of natural gas and propane in 2005, as some households were relying on wood as a substitute

fuel (see Changes in Wood Burning Behavior on page 27). 

TABLE 1 FREQUENCY OF BURNING WOOD THIS WINTER BY STUDY YEAR (N = 864)

Figure 19 provides a useful summary of wood burning behavior among households that own a

heating device in the District overall, as well as by county. Overall, 26% of households expected

to burn wood weekly, 25% expected to burn wood less frequently than once per week, 31% own

a wood burning heating but indicated that they do not expect to burn wood, and 19% own a

heating device that primarily burns fuels other than wood. Among the nine member counties,

Sonoma County had the highest percentage of heating device-owning households that expected

to burn wood weekly (43%), where San Francisco had the lowest (21%).

FIGURE 19 FREQUENCY OF BURNING WOOD THIS WINTER AMONG ALL HEATING DEVICE HOUSEHOLDS BY COUNTY (N = 

1,679)

2005 2004

At least once per week 48.9%† 34.2%

One day 9.3% 11.2%

Two days 11.5%† 5.6%

Three days 10.4% 6.1%

Four days 4.3%† 1.0%

Five days 3.2% 2.6%

Six days 0.8% 1.5%

Seven days 7.2% 6.1%

Not sure # of days 2.2% 0.0%

2 to 3 times per month 18.5%† 28.1%

Once per month 17.0% 15.8%

Less than once per month 11.7%† 18.4%

Not sure of frequency 4.0% 3.6%

Frequency of Burning 

Among Households with 

a Wood-burning Device 

Expected to be Used 

During Winter Season 

(Q9/Q10/Q11)

Study Year

35.0

42.8

34.0

21.4

39.3

27.2

25.8 13.7

17.1

32.1

17.2

22.5

30.7

33.0

24.5 28.7

29.8

31.1

34.2 28.5

30.3

34.4

18.6

25.7

18.1 18.3

9.5 12.4 14.8 18.0 13.2 15.9

25.5 21.9 21.1 22.2

25.2 30.8 36.3

19.3

0

10

20

30

40

50

60

70

80

90

100

BAAQMD

District

Overall

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Heating Device Households

Primarily gas, electric /

never burn wood

Do not expect to burn

Expect to burn less than

once per week

Expect to burn at least

once per week
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 21

WOOD BURNING BEHAVIOR IN PAST WEEK Respondents were also asked whether

they burned wood in the past week and -- if yes -- if they burned wood the day or evening prior to

the interview. The results to these two questions are combined in Figure 20. Forty-three percent

(43%) of respondents whose household includes at least one fireplace, pellet stove and/or wood

stove and expected to burn wood during the winter months indicated that they had burned wood

during the week prior to the interview. Moreover, approximately 22% had burned wood the day

prior to the interview.

Question 12 Did you burn wood in the past seven days? 

Question 13 Did you burn wood yesterday or last night?

FIGURE 20 BURNED WOOD IN PAST SEVEN DAYS (N = 864)

When compared to 2004, a significantly higher percentage of households reported that they had

burned wood in the week prior to the interview. Whereas approximately one-third (32%) reported

burning wood during this period in 2004, the corresponding figure for 2005 was 43% (see Table

2).9

TABLE 2 BURNED WOOD IN PAST SEVEN DAYS BY STUDY YEAR (N = 864)

9. This discrepancy may be partially due to the timing of the interviews. In 2004, the interviews were conducted 

in the last two weeks of the season, whereas in 2005 the interviews were conducted throughout the season.

Burned wood in

past seven days

43.0

Not sure

0.2

Did not burn

wood in last

seven days

56.6

Burned wood

yesterday

21.7

Did not burn

wood

yesterday

21.1

Not sure

0.4

2005 2004

Burned wood in past seven days 43.0%† 32.1%

Burned wood yesterday 21.7% 12.8%

Did not burn woodyesterday 21.1% 19.4%

Not sure of burning yesterday 0.2% 0.0%

Did not burn wood in last seven days 56.6%† 67.3%

Not sure of burning in past seven days 0.4% 0.5%

Study Year

Frequency of Burning in Past 

Seven Days Among 

Households with a Woodburning Device Expected to 

be Used During Winter 

Season (Q12/Q13)
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 22

The following two figures show the percentage of heating device-owning households that burned

wood in the seven days prior to the interview (Figure 21) and on the day prior to the interview

(Figure 22) for the District as a whole, as well as by the nine member counties. Consistent with

prior measures of wood burning frequency, Sonoma County residents reported the highest rate

of wood burning behavior.

FIGURE 21 HEATING DEVICE HOUSEHOLDS THAT BURNED WOOD IN PAST SEVEN DAYS BY COUNTY (N = 1,679)

FIGURE 22 HEATING DEVICE HOUSEHOLDS THAT BURNED WOOD YESTERDAY / LAST NIGHT BY COUNTY (N = 1,679)

30.1

38.1

24.4

16.8

31.5

24.5

22.2

19.8

21.7

19.2

0

5

10

15

20

25

30

35

40

45

50

BAAQMD

District

Overall

Santa

Clara

San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Heating Device Households that Burned

Wood in Past Seven Days

16.2

24.1

13.7

8.4

19.6

11.5

9.7

7.9

9.7

11.2

0

5

10

15

20

25

30

BAAQMD

District

Overall

Santa

Clara

San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Heating Device Households that Burned

Wood Yesterday / Last Night
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 23

During the design stage of the study, it was expected that wood burning behavior could be

linked to both the type of day (weekday, weekend and holiday) and weather-related factors such

as precipitation and temperature. Figure 23 shows that although precipitation and temperature

on the reference day for the interview was clearly related to wood burning behavior on said day

in the expected manner, the type of day did not bare a statistical relationship to wood burning

behavior. Overall, households were no more likely (or unlikely) to burn wood on a holiday or on

weekends than they were on weekdays.

FIGURE 23 HEATING DEVICE HOUSEHOLDS THAT BURNED WOOD YESTERDAY / LAST NIGHT BY DAY TYPE, 

PRECIPITATION ON DAY PRIOR TO INTERVIEW & LOW TEMPERATURE ON DAY PRIOR TO INTERVIEW (N = 1,679)

DURATION & VOLUME OF WOOD BURNING Questions 14 and 15 asked respondents

with wood-burning devices who also expected to use the device this winter to estimate the number of hours they have a fire burning -- as well as the number of logs they burn -- on a typical day

that they burn wood. 

In terms of hours, more than half (53%) of respondents indicated that they burn three to four

hours on a typical day. The remaining respondents were split between those who burn for

shorter durations (27%) and those who burn for five hours or longer (21%). The average duration

among all respondents who received this question was 3.8 hours.

Figure 25 presents the distribution of burning hours on a typical day by county and expected frequency of burning during the 2005-2006 winter season. When compared to their respective

counterparts, Marin County residents reported the longest average duration of wood burning on

a typical burn day at 5.19 hours, followed closely by Sonoma County at 4.88 hours. Frequent

burners also reported a longer duration (4.63 hours) for a typical burn day when compared to

those who burn less than once per week (3.03 hours).

11.1

19.8

15.3

9.2

11.7

10.5 10.4 10.4

11.5

0

5

10

15

20

25

30

Weekday Weekend Holiday None Less than .5

inches

.5 inches or

more

Below 40 40 to 49 50 or over

Day Type Precipitation on Day Prior to Interview Low Temperature of Day Prior to Interview

% Heating Device Households that Burned

Wood Yesterday / Last Night
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 24

Question 14 In a typical day that you burn wood, how many hours of the day do you have a

fire burning? 

FIGURE 24 HOURS OF BURNING IN TYPICAL DAY OF WOOD BURNING (N = 864)

FIGURE 25 DISTRIBUTION AND AVERAGE HOURS OF BURNING IN TYPICAL DAY OF WOOD BURNING BY COUNTY & 

EXPECTED FREQUENCY OF WINTER WOOD BURNING (N = 864)

In terms of volume, respondents were rather evenly split between those who burn one or two

logs per typical burn day (34%), those who estimated that they burn three to five logs (34%), and

those who reported burning more than five logs per day (32%). The average number of logs

reported per burn day was 5.12 (see Figure 26). As shown in Figure 27, those counties that

reported the longest duration of burning on a typical burn day (Marin and Sonoma) also reported

the highest volume of logs burned per burn day (7.0 and 7.6, respectively). Frequent burners

Five or more

hours

21.0

One or two

hours

26.5

Three or four

hours

52.6

12.2

28.3

36.0

21.7 21.8 15.9

35.7

45.4

44.4

52.5

46.1

57.2

53.6

52.0

23.0

10.4

22.1

29.2

42.4

27.3

11.5

32.2

21.0

30.5

12.3

23.9

37.4

24.1

14.5

53.0

56.3

53.9

52.3

0

10

20

30

40

50

60

70

80

90

100

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra Costa At least once

per week

Less than

once per

week

4.24 3.02 3.66 5.19 4.88 4.17 3.01 4.63 3.65 4.63 3.03

County and Average Hours per Burning Expected Frequency of

Winter Wood Burning and

Average Hours per Burning

% Households with Wood-burning Heating Device

Expected to be Used During Winter Season

Five or more

hours

Three or four

hours

One or two

hours
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 25

also reported a higher number of logs burned (6.28) per burn day when compared to their counterparts (3.94) who burn less frequently than once per week.

Question 15 In a typical day that you burn wood, how many logs do you burn throughout the

entire day?

FIGURE 26 LOGS BURNED IN TYPICAL DAY OF WOOD BURNING (N = 864)

FIGURE 27 LOGS BURNED IN TYPICAL DAY OF WOOD BURNING BY COUNTY & EXPECTED FREQUENCY OF WINTER WOOD

BURNING (N = 864)

NON-WINTER WOOD BURNING Whereas the bulk of the questions on wood burning

focused on the winter season, respondents were also asked about their wood burning behavior

during non-winter months. This line of inquiry was administered to all respondents -- not just

those with a heating device in the home -- in order to capture wood burning that occurs at campfires and beaches, in chimineas and at other locations in addition to their home. As shown in

Three to five

34.1

One or two

34.1

Six or more

31.8

18.1

36.2 38.4

25.1

32.7 27.8

40.0

27.0

31.1 29.5

30.8

34.9

31.2

36.7

29.3

15.9

27.3

45.9

54.8

32.8 32.1

44.2

32.4 41.1

23.4

23.9

34.6

53.5

28.3

30.6

38.1

30.1

42.4

0

10

20

30

40

50

60

70

80

90

100

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra Costa At least once

per week

Less than

once per

week

5.05 3.00 4.89 7.00 7.57 5.00 4.75 6.92 5.39 6.28 3.94

County and Average Logs per Burning Expected Frequency of

Winter Wood Burning and

Average Logs per Burning

% Households with Wood-burning Heating Device

Expected to be Used During Winter Season

Six or more

logs

Three to five

logs

One or two

logs
Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 26

Table 3, the vast majority of households (83%) reported that they do not burn wood in non-winter

months. The percentage of respondents that indicated they do burn wood is shown for each nonwinter month overall, as well as according to whether they own a heating device in their home.

Question D1 Do you ever burn wood in non-winter months, between March and October? If no,

record. If yes, ask: Which months during this period to you tend to burn wood? 

TABLE 3 WOOD BURNING ON NON-WINTER MONTHS BY HEATING DEVICE IN HOME

Yes No

March 7.2 8.8 4.3

April 5.3 6.3 3.7

May 3.7 4.0 3.3

June 4.8 4.9 4.7

July 5.1 5.2 4.9

August 4.3 4.2 4.5

September 4.5 4.7 4.2

October 6.4 7.8 3.9

None 82.9 78.8 90.2

Not sure 4.1 5.3 2.0

BAAQMD District 

Overall

Heating Device in Home

QD1 Non-winter 

months 

anticipated for 

wood-burning
Changes in Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 27

C HANGES I N W OOD B URNING B EHAVIOR

Having measured respondents’ basic wood burning behavior, the survey next focused on

whether respondents had made changes in their wood burning behavior during the 2005-2006

winter season in response to the Spare the Air Tonight Campaign or other factors such as the

higher cost of natural gas and propane this season. 

CHANGES IN WOOD BURNING BEHAVIOR The first question in this series simply

asked the respondent if they expected that they would burn wood more frequently, less frequently, or at about the same frequency as the prior winter season. Respondents who indicated

that they expected to burn wood more frequently this season were subsequently asked why they

expected to burn more frequently this season. The responses to both questions are combined in

Figure 28.

Overall, 56% of households that own a wood-burning heating device and expected to burn wood

this season reported that they anticipated burning wood at about the same frequency this season as last. Approximately 16% anticipated burning wood less frequently, whereas 22% expected

to burn wood more frequently in winter 2005-2006 when compared to the prior season. The 22%

who expected to burn more frequently this season were divided rather evenly between those

who were doing so due to the increased cost of energy and gas (10%) and those who were doing

so for other reasons (12%).

Question 16 This winter, do you expect that you will burn wood more often, less often, or

about the same frequency as you did last winter?

Question 17 Why are you burning wood more frequently this year? FIGURE 28 EXPECTED FREQUENCY OF WOOD BURNING THIS WINTER COMPARED TO LAST WINTER AND REASONS FOR BURNING MORE OFTEN (N = 864)

Burn about

the same

55.5

Energy / Gas

costs

10.3

Not sure

6.3

Burn less

often

16.2

Other reason

11.5

Not sure

0.2

Burn more

often

21.9
Changes in Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 28

CHANGES AMONG THOSE WHO INCREASED BURNING Approximately 10% of

households that own a wood-burning heating device and anticipated burning wood this winter

also indicated that they expected to increase their frequency of wood burning in winter 2005-

2006 in response to the high cost of energy and/or gas (see Figure 28). Questions 18, 19 and 20

were designed to profile these respondents’ wood burning during the prior winter season,

thereby allowing a comparison to their expected burning behavior in 2005-2006 which was previously measured in the survey.

Figure 29 shows the distribution of recalled wood burning frequency during the 2004-2005 winter season among respondents who expected to increase their frequency of wood burning in

2005-2006 due to high energy/gas costs. Approximately 62% expected to burn wood at least

once per week, and 22% expected to burn wood at least four days per week.

Question 18 How often did you burn wood last winter? At least once per week or less often

than that? 

Question 19 Last winter, would you say that you burned wood about two to three times per

month, once per month, or less often than once per month? 

Question 20 Last winter, how many days did you burn wood in a typical week? FIGURE 29 FREQUENCY OF WOOD BURNING LAST WINTER AMONG THOSE BURNING MORE OFTEN BECAUSE OF INCREASED ENERGY COSTS (N = 89)

Table 4 on the next page compares the expected frequency of wood burning for the 2005-2006

season and the recalled burning behavior from 2004-2005 among households that expected to

burn wood more frequently this season in response to high energy costs. For reference, the far

right column also shows the frequency of wood burning reported during the 2004 season among

all wood-burning households. The results are consistent with the respondents’ reported behavior. For example, 80% of households that expected to increase their wood burning due to energy

costs anticipated burning at least once per week this winter, compared to just 62% in 2004.

Not sure

2.6

Five days

0.9

Three days

4.4

Two days

8.3

One day

25.0

Four days

15.1

Six days

1.5 Seven days

4.5

2 to 3 times per

month

18.5

Less than once

per month

6.9

Not sure

1.1

Once per month

9.7

At least once

per week

62.3
Changes in Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 29

TABLE 4 FREQUENCY OF WOOD BURNING AMONG THOSE BURNING MORE OFTEN BECAUSE OF INCREASED ENERGY COSTS (N = 89)

REDUCTIONS IN WOOD BURNING Respondents were next asked whether there were

occasions this winter when they normally would have burned wood, but decided not to. If a

respondent indicated that they had refrained from burning wood on at least one occasion, they

were then asked in an open-ended manner to indicate why they reduced their wood burning.10

The manner in which these questions were asked, as well as their placement in the survey relative to specific questions about the Spare the Air Tonight Campaign, was changed in 2004 from

prior surveys. Previous surveys first introduced the Spare the Air Tonight Program and then

asked if individuals responded to the Program by reducing the amount of wood they burned.

Asking the question in this manner is likely to prompt a socially desirable response from some

respondents that they had reduced their wood burning even if they had not -- which leads to artificially high estimates of the campaign’s impact. To more accurately measure reductions in wood

burning that can be attributed to the campaign, the 2004 and 2005 surveys employed an indirect approach similar to that used in the CARB/EPA Method for estimating reductions in driving

due to the summer Spare the Air Campaign. 

As shown in Figure 30, 29% of respondents who have a fireplace, wood stove and/or pellet stove

and expected to burn wood during the 2005-2006 winter season indicated that -- on at least one

occasion -- they refrained from burning wood. When asked why they chose not to burn wood on

these occasions, 1% specifically mentioned the Spare the Air Campaign and an additional 3%

offered an air quality or health-related reason.

10.Respondents were allowed to provide multiple responses to this question, as their reason for not burning 

wood could vary from occasion to occasion.

2005 Recalled 2004

At least once per week 80.2% 62.3% 34.2%

One day 9.2% 25.0% 11.2%

Two days 14.9% 8.3% 5.6%

Three days 20.3% 4.4% 6.1%

Four days 6.2% 15.1% 1.0%

Five days 7.6% 0.9% 2.6%

Six days 0.6% 1.5% 1.5%

Seven days 16.9% 4.5% 6.1%

Not sure # of days 4.5% 2.6% 0.0%

2 to 3 times per month 10.7% 20.0% 28.1%

Once per month 4.3% 9.7% 15.8%

Less than once per month 3.7% 6.9% 18.4%

Not sure of frequency 1.1% 1.1% 3.6%

Households that Will Burn More Wood Because of 

Increased Energy / Gas Costs

Frequency of Burning Among 

Households with a Woodburning Heating Device 

Expected to be Used During 

Winter Season that Will Burn 

More Wood Because of 

Increased Energy / Gas Costs

All Wood-burning 

Households from 2004 

Study Year
Changes in Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 30

Question 21 Were there occasions this winter when you normally would have burned wood, but

decided not to?

Question 22 Why did you decide not to burn wood on these occasions? FIGURE 30 CHOSE NOT TO BURN THIS WINTER (N = 864)

CAMPAIGN IMPACTS ON WOOD BURNING To estimate the proportion of adults in

the District who reduced the amount of wood that they burned during the winter season in

response to the campaign, one must combine the responses from several questions in the survey. Naturally, respondents who do not live in a household that contains a fireplace, wood stove

or pellet stove (Question 1) should not be included in the analysis since they could not respond

to the campaign by reducing their wood burning behavior. Respondents who chose not to burn

wood at all during the winter (Question 7), did so because of air quality reasons (Question 8),

and were aware of the Spare the Air Tonight Program (Question 40) can be considered a Spare

the Air (STA) reducer. So too can respondents who indicated that although they did burn wood,

they refrained from doing so on occasion (Question 21), did so because of the campaign or for

air quality/health reasons (Question 22), and were aware of the Spare the Air Tonight Program

(Question 40).

Table 5 shows that of the 1,679 respondents in the survey who were eligible to respond to the

campaign, 39 (2.3%) reduced their wood burning behavior on at least one occasion during the

2005-2006 winter in response to the Spare the Air Tonight Program.11 This represents 36,547

households out of the estimated 1,555,185 households with a heating device.

11.The survey included a follow-up question (Question 23) which asked respondents who refrained from burning wood for campaign-related reasons (Question 22) how many times they refrained from burning wood for 

air quality reasons during the winter season. The average response was 2.52 times, although the small sample size for this question means that the statistical margins of error around the estimate are large. Moreover, 

respondents who did not burn wood at all during the winter were not asked this question, so the figure represents the average reduction among individuals who normally burn wood.

Not sure

4.8

Air quality /

Health

2.9

Spare the Air

campaign

0.7

No

65.9 Other reason

25.4

Not sure

0.8

Yes

29.3
Changes in Wood Burning Behavior

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 31

TABLE 5 SPARE THE AIR REDUCERS: CONFIDENCE INTERVAL

Figure 31 displays the estimated percentage of heating-device owning households that reduced

their wood burning on at least one occasion due to the Spare the Air Tonight Program by study

year (2005 and 2004), as well as by county for 2005. For reference, the confidence intervals are

also shown to provide a sense for the reliability of the estimates.12 FIGURE 31 SPARE THE AIR REDUCERS BY STUDY YEAR & COUNTY SHOWING CONFIDENCE INTERVALS (

N = 1,679)

12.The confidence intervals indicate the range within which one can be 95% confident that the true value exists.

1,555,185

1,679

39

1639

2.35%

97.65%

0.72%

Lower Bound 1.62%

Upper Bound 3.07%

Confidence Interval for Proportion of 

Winter STA Reducers

Non-STA Reducers

Proportion of STA Reducers

Proportion of Non-STA Reducers

Maximum Margin of Error (95% confidence)

Winter Spare the Air Tonight Reducers

Universe Estimate (households with heating device)

Sample Size (surveyed households with heating device)

STA Reducers

8.11

2.28

3.14

0.96

6.86

1.89

5.19

2.93

8.00

4.22

2.35

0123456789

10

11

12

2005 2004 Santa

Clara

San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

Study Year County

% Heating Device Households
Recall and Awareness of Spare the Air Tonight Messaging

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 32

R ECALL AND A WARENESS O F S PARE

THE A I R T ONIGHT M ESSAGING

Although the ultimate goal of the Spare the Air Tonight Campaign is to persuade individuals to

reduce the amount of wood that they burn and to replace wood burning devices with cleaner

alternatives, there are a series of related objectives which must be met in order for this to occur.

For example, regardless of how compelling the message may be, if the message does not reach

the target audience then the campaign can not succeed in its primary goal. Thus, an instrumental objective of the campaign is to simply increase awareness of the Spare the Air Tonight Program and related events.

RECALL EXPOSURE TO SPARE THE AIR MESSAGING Accordingly, a series of questions was asked of respondents about their recall of Spare the Air Tonight messaging. The first

of these questions asked: During this winter, have you heard, read, or seen any new stories,

advertisements or public service announcements about Spare the Air Tonight, poor air quality,

or requests not to use your fireplace, pellet stove or wood stove?

Figure 32 presents the results to this question for the study years 2002 through 2005. In 2005,

34% of respondents recalled being exposed to news stories, advertisements or public service

announcements related to the Spare the Air Tonight Program during the winter months. Recalled

exposure was significantly lower in 2005 when compared to prior winters, perhaps in part due to

the timing of interviews. In prior years, the interviews were all conducted at the end of the season -- as opposed to throughout the season as in 2005 -- which increases a respondent’s opportunities to be exposed to the campaign.

Question 24 During this winter, have you heard, read, or seen any news stories, advertisements, or public service announcements about Spare the Air Tonight, poor air quality, or

requests not to use your fireplace, pellet stove, or woodstove?

FIGURE 32 HEARD, READ, OR SAW SPARE THE AIR WINTER INFORMATION BY STUDY YEAR (N = 2,625)

Yes, heard,

read, or saw info

34.0†

56.0

42.0 38.7

No, did not

hear, read, or

see info

64.9†

43.0

56.0 60.1

0

10

20

30

40

50

60

70

80

90

100

2005 2004 2003 2002

Study Year

% Respondents
Recall and Awareness of Spare the Air Tonight Messaging

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 33

For the interested reader, Figures 33 and 34 display the percentage of respondents who recalled

being exposed to news stories, advertisements or public service announcements related to the

Spare the Air Tonight Program during the winter months by county, age and household income.

When compared to their respective counterparts, those who reside in Marin and Contra Costa

counties, those 45 years of age or older, and those who enjoy annual family incomes of

$200,000 or more were the most likely to recall being exposed to the Spare the Air Tonight Program.

FIGURE 33 HEARD, READ, OR SAW SPARE THE AIR WINTER INFORMATION BY COUNTY (N = 2,625)

FIGURE 34 HEARD, READ, OR SAW SPARE THE AIR WINTER INFORMATION BY AGE & HOUSEHOLD INCOME (N = 2,625)

32.5

34.9

28.5 29.2

40.5

35.2

31.8

35.1

39.7

0

5

10

15

20

25

30

35

40

45

50

Santa

Clara

San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Respondents

47.0

42.0

30.3

33.6 34.9

37.4

31.3

40.2 41.5

28.9 28.9

19.3

0

5

10

15

20

25

30

35

40

45

50

18 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 and

over

Under

$50K

$50K to

$74K

$75K to

$99K

$100K to

$149K

$150K to

$199K

$200K or

more

Age Household Income

% Respondents
Recall and Awareness of Spare the Air Tonight Messaging

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 34

INFORMATION SOURCE Those who indicated that they recalled hearing, reading, or seeing Spare the Air Tonight related information during the winter were next asked where they

obtained the information. Multiple responses to the question were allowed, so the percentages

shown in Figure 35 represent the percentage of respondents who mentioned a particular source

and thus add to more than 100%. Because this question was asked in an identical manner in the

2002, 2003 and 2004 surveys, the results from these surveys are also included in Figure 35 for

comparison.

As in the previous three surveys, the most popular methods of obtaining information related to

Spare the Air Tonight and air quality during the winter of 2005-2006 were television (45%) and

radio (38%). Within these two sources, however, there appears to be a significant shift since 2003

toward a greater reliance on television and less reliance on radio for this information. Newspapers (17%) were the only other information source mentioned by at least 10% of respondents.

Question 25 Where did you see the news story, advertisement or public service announcement?

FIGURE 35 SOURCE FOR SPARE THE AIR WINTER INFORMATION (N = 891)

45.0

6.9

2.7

1.4 1.0

49.4

7.4

2.2

1.1 1.1 0.7

17.4

38.2

5.4†

17.3

38.4

0

5

10

15

20

25

30

35

40

45

50

Television Radio Newspaper Not sure Billboard Website Bus signs Email Alert

Q25 Spare the Air, air quality information source . . .

% Respondents

2005 2004 2003 2002

Study Year
Attitudes about Wood Smoke

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 35

A TTITUDES ABOUT W OOD S MOKE

In addition to changing wood burning behavior, one of the goals of the Spare the Air Tonight

Program is to change how residents think about wood smoke and its impact on public health. To

track how effective the Program has been in achieving this goal, the survey included several measures of residents’ opinions and perceptions about wood smoke.

The first of these questions simply asked the respondent whether they think there are any negative health effects associated with breathing wood smoke. As shown in Figure 36, approximately

two-thirds (66%) of adults in the Bay Area do perceive wood smoke to have negative health

impacts. Moreover, public opinion on this matter has changed substantially in the past four

years -- in part due to the Spare the Air Tonight Program. The proportion of adults that perceive

wood smoke to have negative health impacts has increased by nearly 17% since 2002.

Question 27 Do you think there are any negative health effects associated with breathing

wood smoke? FIGURE 36 PERCEIVE NEGATIVE HEALTH EFFECTS ARE ASSOCIATED WITH WOOD SMOKE BY STUDY YEAR (

N = 2,625) 

Figures 37 and 38 display how adults in the Bay Area differ in their opinions about the health

impacts of wood smoke based on their county of residence and age, respectively. Although there

were some notable differences by county, attitudes about the health-impacts of wood smoke

bore little relationship to respondent age.

13.5 15.0 12.0

Yes, negative

health effects

from wood

smoke

65.9 49.0

59.0

66.6

No negative

health effects

from wood

smoke

23.5 39.0

26.0

19.9

Not sure

10.7

0

10

20

30

40

50

60

70

80

90

100

2005 2004 2003 2002

Study Year

% Respondents
Attitudes about Wood Smoke

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 36

FIGURE 37 PERCEIVE NEGATIVE HEALTH EFFECTS ARE ASSOCIATED WITH WOOD SMOKE BY COUNTY (N = 2,625)

FIGURE 38 PERCEIVE NEGATIVE HEALTH EFFECTS ARE ASSOCIATED WITH WOOD SMOKE BY AGE (N = 2,625)

73.0

58.0

67.5

54.4

66.2 67.3 66.4 64.0 65.2

0

10

20

30

40

50

60

70

80

90

100

Santa

Clara

San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Respondents

66.1 65.2

61.7 64.2

68.4 69.8

0

10

20

30

40

50

60

70

80

90

100

18 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 and over

Age

% Respondents
Attitudes about Wood Smoke

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 37

Respondents who perceived wood smoke to have negative health impacts (Question 27) were

next asked to identify what the specific health effects are of breathing wood smoke. Multiple

responses were allowed for this question, so the percentages shown in Figure 39 represent the

percentage of respondents who mentioned a particular health effect. The most common

response (36%) was a general reference to lung disease, followed by a specific reference to

asthma (24%). Approximately 12% of respondents mentioned properties of wood -- chemicals,

carcinogens and toxins -- that are released when burned, and an additional 10% mentioned carbon monoxide. Overall, 17% of those who perceived that wood smoke had negative health

impacts could not name a specific impact.13

Question 28 What are the negative health effects associated with breathing wood smoke? FIGURE 39 PERCEIVED NEGATIVE EFFECTS OF BREATHING WOOD SMOKE (N = 1,730)

WOOD SMOKE A NEIGHBORHOOD PROBLEM? Most adults recognize that there are

negative health impacts due to wood smoke. But do they think that their neighborhood has a

wood smoke problem? To answer this question, the survey first informed respondents that different neighborhoods in the Bay Area experience different levels of air pollution from wood

smoke. Respondents were then asked to indicate whether, in their opinion, their neighborhood

periodically experiences air pollution from wood smoke. Those who perceived their neighborhood to have an occasional wood smoke problem were asked in a follow-up question to identify

13.The structure of this question was changed somewhat from that used in 2004, so a direct comparison of 

results is not provided.

3.3

4.2

4.7

8.8

9.7

12.3

17.0

23.9

36.0

0 5 10 15 20 25 30 35 40

Bronchitis

Emphysema

Allergies

Cancer

Carbon monoxide

Toxins in wood

Not sure

Asthma

Lung disease

% Respondents
Attitudes about Wood Smoke

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 38

the magnitude of the problem. The answers to both of these questions are combined in

Figure 40.

Overall, 18% of adults surveyed indicated that their neighborhood periodically experiences air

pollution from wood smoke. Twelve percent (12%) stated that the problem was a small one, 4%

indicated it was a moderate or medium problem, and 1% felt that air pollution due to wood

smoke was a big problem in their neighborhood.

Question 29 Different neighborhoods in the Bay Area experience different levels of air pollution from wood smoke. In your opinion, does your neighborhood periodically experience air pollution from wood smoke?

Question 30 Would you say that periodic air pollution from wood smoke in your neighborhood

is a big problem, medium problem or a small problem? FIGURE 40 PERCEPTION OF PERIODIC WOOD SMOKE PROBLEM IN NEIGHBORHOOD (

N = 2,625)

Figure 41 shows how the answers to Questions 29 and 30 varied by study year and by county

within the Bay Area in 2005. Overall, perceptions of wood smoke being a neighborhood problem

did not change significantly between 2004 and 2005. Among the nine member counties, perceptions of wood smoke as being at least a moderate problem were greatest in Marin (24%), Napa

(22%), and Contra Costa (22%) counties.

Experience

wood smoke

pollution

17.7

Not sure

0.3

Small problem

12.3

Do not 

experience 

wood smoke

pollution

74.4

Big problem

1.1

Medium

problem 4.0

Not sure

7.9
Attitudes about Wood Smoke

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 39

FIGURE 41 PERCEPTION OF WOOD SMOKE PROBLEM IN NEIGHBORHOOD BY STUDY YEAR & COUNTY (N = 2,625)

86.3

75.3

81.9 82.4 81.2 76.9 77.9

9.6

18.4

13.6 13.9 12.0 17.4 16.3

4.4 5.6 3.6 3.0 3.9 5.5 4.1 2.5 6.1 4.9 5.5

86.1

80.1 78.5 81.1

12.8 15.7

8.5 13.4

0

10

20

30

40

50

60

70

80

90

100

2005 2004 Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

Study Year County

% Households

Big problem

Medium

problem

Small problem

Do not

experience

wood smoke

pollution
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 40

C HANGING H EATING D EVICE

Reducing the amount of air pollution caused by wood burning is the ultimate goal of the Spare

the Air Tonight Program. Toward this end, the Program adopts both direct and indirect strategies. Direct strategies encourage individuals to simply not use their fireplace, wood stove or pellet stove -- or to use it less frequently. For respondents who depend on their fireplace or stove

for heat, however, this strategy may not be practical or effective. For these and other individuals,

the Program also employs strategies to reduce wood smoke pollutants indirectly -- that is, by

changing the type of fuel burned and/or the efficiency of the heating device, rather than the frequency of burning.

To understand the potential impact that these indirect strategies may have on air pollution from

wood smoke, the first task is to develop a profile of the specific type of heating devices that are

owned by Bay Area residents. In addition to understanding the number of fireplaces, wood

stoves and pellet stoves that are owned by respondents (see Heating Devices on page 9) and the

type of fuel that they burn (see Fuel Type & Source on page 11), respondents with wood stoves or

pellet stoves were also asked to identify whether their stove is EPA certified. Figure 42 shows

that in 2005 most respondents (59%) thought that their stove was EPA certified, whereas 13%

indicated that it was not and 28% were unsure. The 2004 results are also shown in Figure 42 for

comparison.

Question 31 Is your woodstove or pellet stove EPA certified? If not sure, clarify: Wood stoves

and pellet stoves manufactured after 1992 are EPA certified, while older ones are not. FIGURE 42 WOODSTOVE OR PELLET STOVE EPA CERTIFIED BY STUDY YEAR (N = 328)

22.7

61.3

Yes, EPA

certified

59.3

No, not EPA 16.0

certified

12.8

Not sure

27.9

0

10

20

30

40

50

60

70

80

90

100

2005 2004

Study Year

% Households with Woodstove or Pellet Stove
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 41

WILLINGNESS TO CHANGE HEATING DEVICE For respondents who owned a woodburning fireplace and/or a non-EPA certified wood stove or pellet stove, the survey next inquired

as to whether the respondent would be willing to replace their current device with a gas fireplace

(Question 32) or EPA certified wood stove or pellet stove (Question 33) that would burn much

cleaner and be less polluting. The responses to both of these questions are presented in

Figure 43. Overall, 28% of respondents in 2005 were willing to replace their current device with a

gas fireplace, whereas a slightly higher percentage (34%) were willing to replace their device with

an EPA certified wood stove or pellet stove. The results are statistically similar to those found in

2004.

Question 32 Gas fireplaces and EPA certified wood stoves, inserts or pellet stoves burn much

cleaner and are less polluting than traditional fireplaces or old wood stoves. Would you be willing

to replace your traditional fireplace, non-EPA certified woodstove or pellet stove with a gas fireplace? 

Question 33 Would you be willing to replace your traditional fireplace, non-EPA certified woodstove or pellet stove with an EPA certified woodstove or pellet stove? FIGURE 43 WILLINGNESS TO REPLACE FIREPLACE OR STOVE WITH EPA CERTIFIED MODEL (N = 913)

Figures 44 and 45 show the proportion of respondents who were administered these questions

that were willing to replace their fireplace or non-EPA certified stove, respectively, with a cleaner

burning model by county and age. Interestingly, although residents in all counties displayed a

greater willing to replace a current device with an EPA certified wood burning model when compared to a gas model, this disparity was particularly pronounced among Sonoma County residents -- who also happen to be the group with the highest proportion of frequent wood burners.

6.5 10.9 9.1

Yes, willin

g to

replace

27.5

30.0 32.6 33.6

No, not willing

to replace

62.6

60.9 55.6 60.9

Not sure

9.9

0

10

20

30

40

50

60

70

80

90

100

2005 2004 2005 2004

Q31 Replace traditional fireplace or stove with gas

model?

Q32 Replace traditional fireplace or stove with EPA

certified model?

% Households with Non-EPA Certified

Wood-burning Device
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 42

Willingness to replace an existing device with an EPA certified device generally declined with age

(see Figure 45). FIGURE 44 WILLINGNESS TO REPLACE FIREPLACE OR STOVE WITH EPA CERTIFIED MODEL BY COUNTY (

N = 913)

FIGURE 45 WILLINGNESS TO REPLACE FIREPLACE OR STOVE WITH EPA CERTIFIED MODEL BY AGE (N = 913)

Questions 32 and 33 measured respondents’ willingness to replace their current heating devices

in the absence of a financial incentive to do so. For those respondents who were unwilling to

20.3

23.2

32.9

18.9

23.7

37.8

30.8

28.7

26.6

24.4

28.4

30.7

26.9

43.1

32.5 31.0 32.4

35.2

0

10

20

30

40

50

60

70

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Households with Non-EPA Certified

Wood-burning Device

Willing to replace traditional fireplace or stove with gas model

Willing to replace traditional fireplace or stove with EPA certified model

28.8 27.3

34.7

23.6

29.1 30.1

60.0

32.4 32.9

37.9

28.1

26.0

0

10

20

30

40

50

60

70

18 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 and over

Age

% Households with Non-EPA Certified

Wood-burning Device

Willing to replace traditional fireplace or stove with gas model

Willing to replace traditional fireplace or stove with EPA certified model
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 43

replace their current device in this context, the survey next inquired as to whether they would do

so if they were offered a financial incentive.

In Question 34, respondents who indicated that they were unwilling to replace their current heating device for a cleaner alternative (Questions 32 and 33) were first informed that there is a government sponsored program that offers rebates to residents who replace their traditional

fireplace or non-EPA certified stove with a gas fireplace or EPA certified wood stove or pellet

stove. They were then asked if they would participate in this program knowing that they would

receive a $200 rebate. For those who remained unwilling at $200, rates of $300, $400 and $500

were tested in sequential order.

As shown in Figure 46, 10% of those who were initially unwilling to replace their heating device

for a cleaner alternative were willing to do so if a $200 rebate were offered. As the amount of the

rebate increased to $300, $400 and $500, the proportion of respondents who indicated that

they would participate in the program increased to 13%, 16% and 23%, respectively. Combining

residents who are willing to replace their current devices without a financial incentive (see

Figure 43) with those who require $200 suggests approximately 38% of the target population

would be receptive to a modest rebate program. 

Question 34 There is a government sponsored program that offers rebates to residents who

replace their traditional fireplace or non-EPA certified woodstove or pellet stove with a gas fireplace or EPA certified woodstove or pellet stove. If you knew that you could receive a rebate of:

_____ dollars, would you participate in this program? FIGURE 46 WILLINGNESS TO PARTICIPATE IN GOVERNMENT-SPONSORED REBATE PROGRAM (

N = 511)

12.8 16.0

23.2

Yes

10.1

68.2 64.3

58.9

No

70.9

17.9 Not sure

19.0 19.0 19.7

0

10

20

30

40

50

60

70

80

90

100

$200 rebate $300 rebate $400 rebate $500 rebate

Q34 Willing to replace non-EPA heating device for . . .

% Households with Non-EPA Certified Wood-burning Device

Unwilling to Voluntarily Replace Heating Device
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 44

RECALL NEWS STORY, ADVERTISEMENT OR ANNOUNCEMENT? Two counties

(Santa Clara and Marin) that are served by the BAAQMD currently offer rebate programs similar

to that described above that partially reimburse residents for the cost of replacing a traditional

fireplace with a gas fireplace or an EPA certified fireplace, wood stove or pellet stove. In Questions 35 and 36, respondents who reside in these two counties were asked if -- in the three

months prior to taking the interview -- they had heard, read or seen any news stories, advertisements or public service announcements about their county’s program. The answers to this question are shown for Santa Clara County and Marin County in Figures 47 and 48, respectively.

Overall, just 6% of Santa Clara County residents -- and 4% of Marin County residents -- could

recall hearing, reading or seeing a news story, advertisement or public service announcement

about the rebate program. The proportion of those who recalled exposure to the rebate program

remained virtually unchanged from that recorded in 2004 for Santa Clara residents, but was

lower in 2005 among Marin County residents.

Question 35 Santa Clara County has a program to offer residents a rebate for replacing a traditional fireplace with a gas burning fireplace or an EPA certified fireplace, woodstove or pellet

stove. In the past three months, have you heard, read or seen any news stories, advertisements

or public service announcements about this program? FIGURE 47 SANTA CLARA COUNTY PROGRAM AWARENESS BY STUDY YEAR (

N = 637)

Heard about

program

5.7 5.5

Did not hear

about 

program

93.4

93.9

0

10

20

30

40

50

60

70

80

90

100

2005 2004

Study Year

% Santa Clara County Respondents
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 45

Question 36 Marin County has a program to offer residents a rebate for replacing a traditional fireplace with a gas burning fireplace or an EPA certified fireplace, woodstove or pellet

stove. In the past three months, have you heard, read or seen any news stories, advertisements

or public service announcements about this program? FIGURE 48 MARIN COUNTY PROGRAM AWARENESS BY STUDY YEAR (

N = 109)

POLICY ATTITUDES The final three questions in this series measured residents’ support

for several policy changes designed to improve the air quality in the region. In Question 37, all

respondents were asked whether they would support a local policy that would require all new

housing construction to use only gas fireplaces or EPA certified fireplace inserts, wood stoves or

pellet stoves. Question 38 measured respondent support for a local policy that prohibits wood

burning on nights when air pollution is expected to reach unhealthy levels. Finally, Question 39

inquired as to residents’ willingness to support a policy that would require older wood stoves to

be removed or replaced with a less polluting model when a home is sold to a new owner. The

answers to all three questions have been combined in Figure 49.

For each of the policies tested, the predominant position was one of support for the policy. Sixtyone percent (61%) supported requiring all new housing construction to use only gas or EPA certified models, 74% favored prohibited wood burning on nights when air pollution is expected to

reach unhealthy levels, and 50% favored requiring the replacement of older woodstoves with a

cleaner burning model when a home is sold to a new owner.

7.1

Heard about

program

3.6

89.3

Did not hear

about 

program

96.4

0

10

20

30

40

50

60

70

80

90

100

2005 2004

Study Year

% Marin County Respondents
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 46

Question 37 Local governments throughout the Bay Area are considering a policy that would

require all new housing construction to use only gas fireplaces or EPA certified fireplace inserts,

wood stoves or pellet stoves. Would you support or oppose this policy?

Question 38 In some areas, local governments have a policy that prohibits wood burning on

nights when air pollution is expected to reach unhealthy levels. Would you support or oppose a

policy like this in your area? 

Question 39 In some areas, local governments require that when a home that contains an

older woodstove is sold to a new owner, the stove must be removed -- or replaced with a new

stove or fireplace that causes less pollution. Would you support or oppose a policy like this in

your area? FIGURE 49 SUPPORT FOR PROPOSED POLICY CHANGES (

N = 2,625)

Question 37 was also asked in 2004 and -- as shown in Figure 50 -- public opinion on this matter

has not changed in the past year. For the interested reader, Figures 51-53 show how support for

each policy varied by county, age, household income, and the type of home in which a respondent lived. Perhaps the most interesting pattern in the results is that support for the replacement

of older woodstoves when a home is sold to a new owner was notably lower among those age

groups and income brackets that are likely to be home owners, as well as those who live in the

type of home (detached) that is most likely to have a wood stove.

7.4 10.1

Support

61.0

49.8

73.9

Oppose

24.1 40.1

18.7

Not sure

14.9

0

10

20

30

40

50

60

70

80

90

100

Q37 Gas fireplace or EPA certified

model requirement in new

housing

Q38 Prohibiting burning on nights

with unhealthy air pollution

levels

Q39 Required replacement of

older wood stove upon sale of

home

% Respondents
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 47

FIGURE 50 SUPPORT FOR PROPOSED EPA CERTIFICATION REQUIREMENTS IN NEW HOUSING CONSTRUCTION BY STUDY

YEAR (N = 2,625)

FIGURE 51 SUPPORT FOR PROPOSED POLICY CHANGES BY COUNTY (N = 2,625)

16.6

62.9

Support

61.0

20.6 Oppose

24.1

Not sure

14.9

0

10

20

30

40

50

60

70

80

90

100

2005 2004

Study Year

% Respondents

60.9

54.7

61.3

53.1

57.7

70.0 69.0

79.1

49.5 50.2

47.3 49.6

56.9

45.8

50.3

46.8

50.7

63.7

70.2

62.3

59.2

75.7

78.1 79.1

74.2

65.4 67.3

0

10

20

30

40

50

60

70

80

90

100

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra Costa

County

% Respondents

Support gas fireplace or EPA certified model requirement in new housing

Support prohibiting burning on nights with unhealthy air pollution levels

Support required replacement of older wood stove upon sale of home
Changing Heating Device

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 48

FIGURE 52 SUPPORT FOR PROPOSED POLICY CHANGES BY AGE (N = 2,625)

FIGURE 53 SUPPORT FOR PROPOSED POLICY CHANGES BY HOUSEHOLD INCOME & HOME TYPE (N = 2,625)

57.7 58.3

62.7

50.4

47.0 48.5 49.8

47.5

58.0 60.3

67.7 65.7

74.6

79.0

68.6

76.2 77.9

71.3

0

10

20

30

40

50

60

70

80

90

100

18 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 and over

Age

% Respondents

Support gas fireplace or EPA certified model requirement in new housing

Support prohibiting burning on nights with unhealthy air pollution levels

Support required replacement of older wood stove upon sale of home

62.7

57.6

52.7

64.6

70.7

63.6

59.3

70.1

80.9

74.7 75.4

68.4

59.4 58.9

53.0

45.3

38.3

42.6

56.1

67.0

53.3

46.4

60.6 60.4

65.9 65.1 63.2

75.1

78.7

75.4 75.3 73.3 71.6

0

10

20

30

40

50

60

70

80

90

100

Under $50K $50K to

$74K

$75K to

$99K

$100K to

$149K

$150K to

$199K

$200K or

more

Apartment Condo Townhome Detached Mobile home

Household Income Home Type

% Respondents

Support gas fireplace or EPA certified model requirement in new housing

Support prohibiting burning on nights with unhealthy air pollution levels

Support required replacement of older wood stove upon sale of home
Perceptions of Entities

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 49

P ERCEPTIONS O F E NTITIES

To identify and track perceptions of the BAAQMD and the Spare the Air Tonight Campaign, a

series of three questions was presented to respondents to measure their awareness and opinions of the agency and the program, as well their recent exposure to information about each.

Because these questions were asked in an identical manner in the 2004, 2003 and 2002 winter

surveys, the results from these studies are also shown for comparison.

AWARENESS Figure 54 shows that awareness of the BAAQMD (56%) remained statistically

similar to awareness of the agency in prior years. The same is true of awareness of the Spare the

Air Tonight Campaign (46%). 

Question 40 Let's change gears a bit. Have you ever heard of the _____?

FIGURE 54 AWARENESS OF BAAQMD & SPARE THE AIR TONIGHT CAMPAIGN BY STUDY YEAR (N = 2,625)

Across the nine member counties, awareness of the BAAQMD was highest in Marin County (69%)

and lowest in San Francisco (49%). Awareness of the Spare the Air Tonight Program displayed

less variation, ranging from a high of 56% in Sonoma County to a low of 43% in San Francisco

County (see Figure 55).

46.4 47.7 49.8 48.0

50.2 52.0

57.1 Yes 60.5 59.0

55.8

53.6 52.3

42.9 No 39.5 41.0

44.2

0

10

20

30

40

50

60

70

80

90

100

2005 2004 2003 2002 2005 2004 2003 2002

Q40a Heard of Bay Area Air Quality Management District Q40b Heard of Spare the Air Tonight Campaign

% Respondents
Perceptions of Entities

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 50

FIGURE 55 AWARENESS OF BAAQMD & SPARE THE AIR TONIGHT CAMPAIGN BY COUNTY (N = 2,625)

OPINIONS Respondents who had heard of an entity were next asked whether their opinion of

the entity was favorable, unfavorable, or neutral. Figure 56 displays the findings of these questions in 2005, as well as the findings from the 2004 and 2003 studies.14

Of the individuals who received the question in 2005, half (51%) held a favorable opinion of the

BAAQMD, whereas 38% held a neutral opinion and just 8% held an unfavorable opinion. When

compared to the opinions recorded in the previous studies, opinions of the BAAQMD have

become increasingly favorable -- from 29% favorable in 2003 to 51% favorable in 2005.

The same is also true of public opinion regarding the Spare the Air Tonight Campaign, although

the trend is less pronounced. Whereas 56% of respondents who had heard of the campaign held

a favorable opinion of it in 2003, the corresponding percentage for 2005 was substantially

higher at 64%.

14.The response options for these questions were more limited in the 2002 study, so comparisons are not provided in Figure 56.

63.4

56.5 59.1 56.6

59.7

43.5

46.2

50.4 49.2

69.3

58.8

48.8

45.9 45.9 47.1

43.3

55.7

46.6

0

10

20

30

40

50

60

70

80

90

100

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Respondents

Heard of Bay Area Air Quality Management District

Heard of Spare the Air Tonight Campaign
Perceptions of Entities

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 51

Question 41 Generally speaking, would you say you have a favorable or unfavorable opinion of

the _____, or do you have no opinion either way? Get answer and ask: Would that be very or

somewhat favorable / unfavorable?

FIGURE 56 OPINIONS OF BAAQMD & SPARE THE AIR CAMPAIGN BY STUDY YEAR (BAAQMD: N = 1,466; STA 

TONIGHT CAMPAIGN: N = 1,218)

EXPOSURE TO INFORMATION The last question in this series asked respondents

whether they recalled hearing, reading or seeing any news stories, advertisements or public service announcements about the BAAQMD and/or the Spare the Air Tonight Program in the six

months prior to the interview. As shown in Figure 57, the proportion of respondents who

recalled being exposed to information about the BAAQMD during this period was 35%, up

slightly from 33% in 2004. On the other hand, the proportion of respondents who recalled exposure to the Spare the Air Tonight Program was 43%, down slightly from 49% in 2004. With

respect to the Program, however, it may be that the disparity between 2004 and 2005 is partially

a reflection of the timing of the interviewing. As noted previously in this report, the 2004 surveys

were conducted at the end of the season, which maximized a respondent’s opportunity to be

exposed to information about the Program. Interviews for the 2005-2006 season were distributed throughout the season, which meant that some respondents would have had a much more

limited opportunity to be exposed to the campaign.

For the interested reader, Figures 58 and 59 display the percentage of all respondents who

recalled hearing, reading or seeing information about the BAAQMD and the Spare the Air Tonight

Program -- not just among those who had heard of the agency or program as shown in Figure 57.

Among all respondents, recalled exposure was greatest for both the agency and the program

among Contra Costa residents (see Figure 58), those with heating devices in the home (see Figure 59), and respondents between the ages of 45 and 54 (see Figure 59).

34.4

23.6

42.0

58.3

25.7 28.4

35.2

3.4 4.3 4.1 2.2 3.6 2.5

4.4 3.3 5.8 2.5

3.8 5.1 2.9 5.2 4.6 4.0

20.1†

31.6

9.1

15.8

30.7

32.1

19.8

29.5

28.1

32.2

37.6

3.2† 0.9

0

10

20

30

40

50

60

70

80

90

100

2005 2004 2003 2005 2004 2003

Q41a Opinion of Bay Area Air Quality Management District Q41b Opinion of Spare the Air Tonight Campaign

% Respondents who Had Heard of Entity

Not sure

Very

unfavorable

Somewhat

unfavorable

No opinion

Somewhat

favorable

Very

favorable
Perceptions of Entities

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 52

Question 42 In the past six months, have you heard, read, or seen any news stories, advertisements, or public service announcements about the _____?

FIGURE 57 ENCOUNTERED INFO ABOUT BAAQMD & SPARE THE AIR TONIGHT CAMPAIGN IN PAST SIX MONTHS BY

STUDY YEAR (BAAQMD: N = 1,466; STA TONIGHT CAMPAIGN: N = 1,218)

FIGURE 58 ENCOUNTERED INFO ABOUT BAAQMD & SPARE THE AIR TONIGHT CAMPAIGN IN PAST SIX MONTHS BY

COUNTY (N = 2,625)

42.6

48.5 52.3

45.0

47.2

54.0

6.5 6.2 5.4

Yes

35.1

40.0

28.9 33.3

No

58.5

59.0

60.3 70.7

51.2

46.1

Not sure

6.4

0

10

20

30

40

50

60

70

80

90

100

2005 2004 2003 2002 2005 2004 2003 2002

Q42a Heard, read, or saw news, ads, PSAs about Bay

Area Air Quality Management District in past six months

Q42a Heard, read, or saw news, ads, PSAs about Spare

the Air Tonight Campaign in past six months

% Respondents who Had Heard of Entity

21.0 20.4

18.5

20.0

21.0

25.4

22.2

17.0

15.2

26.7

19.6 19.2

18.2

16.6

19.8

18.9 18.4

19.2 19.4

20.3

0

5

10

15

20

25

30

BAAQMD

District

Overall

Santa Clara San

Francisco

San Mateo Marin Sonoma Solano Alameda Napa Contra

Costa

County

% Respondents

Heard, read, or saw BAAQMD info in past six months

Heard, read, or saw STA Tonight Campaign info in past six months
Perceptions of Entities

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 53

FIGURE 59 ENCOUNTERED INFO ABOUT BAAQMD & SPARE THE AIR TONIGHT CAMPAIGN IN PAST SIX MONTHS BY

HEATING DEVICE IN HOME & AGE (N = 2,625)

21.2

28.4

24.4

17.5

21.0

17.9

21.7

16.1

4.6

15.9

22.9

18.3

11.4

14.2

20.5

25.8

0

5

10

15

20

25

30

Yes No 18 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 and over

Heating Device in Home Age

% Respondents

Heard, read, or saw BAAQMD info in past six months

Heard, read, or saw STA Tonight Campaign info in past six months
Background & Demographics

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 54

B ACKGROUND & D EMOGRAPHICS

Table 6 displays the demographic and background information collected during the survey.

Because of the sampling methodology used in the study as well as the weighting scheme, the

results shown below are representative of the adult population within the nine-county District.15

The demographic and background information was used to monitor the sample during data collection, as well as provide insight into how the results of the substantive questions of the survey

vary across important subgroups of adults. TABLE 6 BACKGROUND AND DEMOGRAPHICS (N = 2,625)

15.For more information on the sampling method and data collection protocol, please refer to Methodology on 

page 55.

2005 2004 2003 2002

Total Respondents 2,625 700 400 400

Drivers in Household % % % %

Zero to one 27 27 31 32

Two to three 64 65 59 60

Four or more 7 7 10 8

Refused 2211

Age

18 to 29 20 11 16 15

30 to 39 22 19 19 18

40 to 49 20 23 21 18

50 to 64 19 18 25 27

65 and over 14 21 13 18

Refused 5875

Home Type

Apartment 21 20 21 16

Condo 6452

Town home 8854

Single-family detached 60 63 66 73

Mobile home 2224

Refused 4331

Age of Home

0 to 10 years 11 10 14 20

11 to 20 years 14 10 9 18

21 to 30 years 13 12 14 20

31 to 40 years 13 13 15 10

41 to 50 years 10 11 14 8

Over 50 years 27 30 18 10

Not sure / Refused 13 14 16 15

Household Income

Under $50,000 21 22 24 33

$50,000 to $74,999 16 18 17 20

$75,000 to $99,999 15 16 16 13

$100,000 to $149,999 17 14 15 9

$150,000 to $199,999 6633

$200,000 or more 7462

Not sure / Refused 18 19 20 21

Gender

Male 48 43 45 44

Female 52 57 55 56

County

Alameda 21 23 22 -

Contra Costa 14 15 14 -

Marin 444 -

Napa 222 -

San Francisco 13 14 14 -

San Mateo 11 10 11 -

Santa Clara 24 23 23 -

Solano 635 -

Sonoma 556 -

Study Year
Methodology

Winter Spare the Air Tonight Study BAAQMD © 2006

. . . . . . . . . . . . . . . . 55

M ETHODOLOGY

This section of the report outlines the methodology and protocols used when conducting this

study, as well as the motivation for employing certain techniques.

QUESTIONNAIRE With the questionnaire used in 2004 as a starting point, Dr. McLarney of

True North Research worked closely with the BAAQMD to develop and refine an improved survey

instrument for the 2005 study. To more reliably measure the quantity of wood burned by each

person, the relevant questions were revised in 2005 to focus on the amount they burned in a typical fire -- rather than for the entire season as in 2004. Questions were also added to the 2005

instrument to capture the type of wood burned, the source of the wood, the duration of the typical fire, the primary reason for burning wood, as well as changes in wood burning when compared to the prior season.

The 2005 questionnaire also incorporated several improvements that were first implemented in

2004. The most notable of these changes addressed how the questionnaire measured the

impacts of the Spare the Air Tonight Program. The changes were made so that the impacts of the

winter program on wood burning behavior would be measured using the same basic methodology employed by the BAAQMD -- and recommended by CARB and EPA16 -- to measure the

impacts of the summer Spare the Air Program on driving behavior.17

Because these improvements often involved changing the wording, format and/or response

options for a particular question, it is not possible to statistically compare the results of the

2005 survey with previous surveys for select measures. Where such comparisons are possible,

however, this report presents the results from past surveys.

CATI & PRE-TEST Before fielding the survey, the questionnaire was CATI (Computer

Assisted Telephone Interviewing) programmed to assist the live interviewers when conducting

the interviews. The CATI program automatically navigates the skip patterns, randomizes the

appropriate question items, and alerts the interviewer to certain types of keypunching mistakes

should they happen during the interview. The integrity of the questionnaire was pre-tested internally by True North and by dialing into random homes within the District prior to formally beginning the survey. Two training sessions were conducted to familiarize interviewers with the study

and to answer questions and clarify details of the study.

16.The CARB/EPA Method is summarized in the Transportation Research Board’s (TRB) journal --Transportation 

Research Record -- for 2004 in an article entitled Development of a Quantification Method for Measuring the 

Travel and Emissions Impacts of Episodic Ozone Alert Programs (pages 153-159). It is described in detail in 

the following air resources guidance report: CARB, “Quantification Method Reference Manual: A Method to 

Measure Travel and Emissions Impacts of Ozone Action Public Education Programs,” April 2003. In addition 

to Eric Schreffler, Dr. Timothy McLarney and Richard Sarles, the TRB paper and guidance report were coauthored by Joann Lu and Jeff Weir of CARB, as well as Thomas Higgins and Dr. Will Johnson of K.T. Analytics.

17.For a detailed description of the updated CARB/EPA Method and its application to the BAAQMD’s summer 

Spare the Air Program, see the Spare the Air Study: 2004 Summer Ozone Season report prepared for the 

BAAQMD by True North & ESTC.
Methodology

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SAMPLE & WEIGHTING Because the primary focus of the study was to gather information

from adults who reside within the District, households were chosen for this study using a random digit dial (RDD) sampling method. An RDD sample is drawn by first selecting all of the

active phone exchanges (first three digits in a seven digit phone number) and working blocks

that service the area. After estimating the number of listed households within each phone

exchange that are located within the area, a sample of randomly selected phone numbers is generated with the number of phone numbers per exchange being proportional to the estimated

number of households within each exchange in the area. This method ensures that both listed

and unlisted households are included in the sample. It also ensures that new residents and new

developments have an opportunity to participate in the study, which is not true if the sample

were based on a telephone directory.

Although the RDD method is widely used for local and regional surveys, the method also has several known limitations that must be adjusted for to ensure representative data. Research has

shown, for example, that individuals with certain demographic profiles (e.g., older women) are

more likely to be at home and are more likely to answer the phone even when other members of

the household are available. If this tendency is not adjusted for, the RDD sampling method will

produce a survey that is biased in favor of women -- particularly older women. To adjust for this

behavioral tendency, the survey included a screening question which initially asked to speak to

the youngest male adult available in the home. If a male adult was not available, then the interviewer was instructed to speak to the youngest female adult currently available. This protocol

was followed -- to the extent needed -- to ensure a representative sample of adults. In addition to

following this protocol, the sample demographics were monitored as the interviewing proceeded

to make sure they were within certain tolerances. Because the District is composed of seven complete counties and two partial counties, respondents were initially asked the ZIP code of their

residence so that only those within the District’s boundaries were included in the study.

To accommodate the District’s interest in obtaining statistically reliable estimates within each of

the nine member counties, as well as to explore the relationship between both weather and special events on wood burning behavior, the study employed a sampling strategy that involved

stratification by county, month, and day type with strategic oversampling for select counties and

day types. To adjust for the oversampling, the raw data were then weighted by day type, respondent age, and adult population estimates by county prior to analyses and presentation. The

results presented in this report are the weighted results, which are representative at the Districtwide level, as well as within the nine member counties.

MARGIN OF ERROR By using an RDD probability-based sample and monitoring the sample

characteristics as data collection proceeded, True North ensured that the sample was representative of adults and households in the District. The results of the sample can thus be used to estimate the opinions of all adults -- and characteristics of all households -- in the District. Because

not every adult or household in the District participated, however, the results have what is

known as a statistical margin of error due to sampling. For household characteristics, the margin

of error refers to the difference between what was found in the survey of 2,625 households for a

particular question and what would have been found if all of the estimated 2,432,147 households in the District had been interviewed.
Methodology

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For example, in estimating the percentage of households who have at least one heating device in

their home, the margin of error can be calculated if one knows the number of households in the

District, the size of the sample, a chosen confidence level, and the distribution of responses to

the question. The appropriate equation for estimating the margin of error, in this case, is shown

below.

where is the proportion of households who indicated that they have at least one heating

device in their home (0.639 for 63.9%, for example), is the total number of households in the

District (2,432,147), is the sample size that received the question (2,625), and is the upper

 point for the t-distribution with degrees of freedom (1.96 for a 95% confidence interval). Solving this equation using these values reveals a margin of error of +/- 1.84%. This means

that, with 63.9% of sampled households indicating that they own at least one heating device, one

can be 95 percent confident that the actual percentage is between 62% and 66%.

Figure 60 provides a graphic plot of the maximum margin of error in this study. The maximum

margin of error for a dichotomous percentage result occurs when the answers are evenly split

such that 50% provide one response and 50% provide the alternative response (i.e., =0.5). For

this survey, the maximum margin of error is 1.91% for District-wide estimates, and ranges from

5.92% to 6.64% for estimates within counties.

FIGURE 60 MAXIMUM MARGIN OF ERROR PLOT

pˆ t N n –

N------------     pˆ 1 – pˆ ( )n – 1 ± -------------------

pˆ

N

n t

α ⁄ 2 n – 1

pˆ

Sample within

counties

+/- 5.92% to

+/- 6.64%

Sample of 2,625

Households

± 1.91%

0%

2%

4%

6%

8%

10%

12%

14%

0

100200300400500600700800900

100011001200130014001500160017001800190020002100220023002400250026002700280029003000

Sample Size (Number of Households)

Margin of Error
Methodology

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Within this report, figures and tables show how responses to certain questions varied by county,

as well as by demographic characteristics such as presence of a heating device, respondent age,

etc. Because the margin of error grows exponentially as the sample size decreases (see the left

side of Figure 60), the reader should use caution when generalizing and interpreting the results

of questions received by only a small percentage of the sample or when comparing results within

subgroups of respondents.

DATA COLLECTION Interviews were conducted via telephone during weekday evenings

(5:30PM to 9PM) and on weekends (10AM to 5PM) on randomly selected dates between November 22, 2005 and February 17, 2006. It is standard practice not to call during the day on weekdays because most working adults are unavailable and thus calling during those hours would

bias the sample. Table 7 displays the number of interviews completed in each county, and Table

8 displays the date, day type, and number of interviews completed for the entire season.

TABLE 7 COMPLETED INTERVIEWS BY COUNTY (UNWEIGHTED) 

TABLE 8 INTERVIEW DATES (UNWEIGHTED)

County Completed Interviews

Alameda 305

Contra Costa 337

Marin 292

Napa 309

San Francisco 284

San Mateo 293

Santa Clara 288

Solano 288

Sonoma 229

Date Completed Interviews Day Prior to Interview

Nov 22 108 Weekday

Nov 25 105 Holiday

Nov 26 104 Holiday

Nov 28 103 Weekend

Nov 30 100 Weekday

Dec 6 101 Weekday

Dec 7 100 Weekday

Dec 12 103 Weekend

Dec 13 104 Weekday

Dec 16 106 Weekday

Dec 22 112 Weekday

Dec 26 99 Holiday

Dec 27 67 Holiday

Jan 3 101 Weekday

Jan 4 101 Weekday

Jan 9 105 Weekend

Jan 12 98 Weekday

Jan 21 98 Weekday

Jan 22 92 Weekend

Jan 23 105 Weekend

Jan 24 100 Weekday

Jan 27 100 Weekday

Jan 29 80 Weekend

Feb 13 131 Weekend

Feb 14 45 Weekday

Feb 15 72 Weekday

Feb 16 47 Weekday

Feb 17 38 Weekday
Methodology

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DATA PROCESSING Data processing consisted of checking the data for errors or inconsistencies, coding and recoding responses, categorizing open-end responses, and preparing frequency analyses and crosstabulations. Because the research objectives involved comparing the

2005 results with those of prior studies, where appropriate, True North also accessed and processed data from the 2004, 2003 and 2002 winter season surveys to allow for meaningful comparisons. Additionally, meteorological data supplied by the BAAQMD including precipitation,

temperature and heating degree days was merged to the survey data based on the reference day

and ZIP code.

ROUNDING Numbers that end in 0.5 or higher are rounded up to the nearest whole number, whereas numbers that end in 0.4 or lower are rounded down to the nearest whole number.

These same rounding rules are also applied, when needed, to arrive at numbers that include a

decimal place in constructing figures and charts. Occasionally, these rounding rules lead to

small discrepancies in the first decimal place when comparing tables and pie charts for a given

question.
Questionnaire & Toplines

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Q UESTIONNAIRE & T OPLINES

BAAQMD © 2005 Page 1 

Winter 05-06 Spare the Air Survey 

Designed by True North Research 

Final Toplines for Season 

2,625 Respondents 

Section 1: Introduction to Study 

Hi, my name is _____ and I’m calling on behalf of TNR, a public opinion research firm. We’re 

conducting a survey concerning issues of importance to residents in the Bay Area region and 

we’d like to get your opinions. 

If needed: This is only a survey about important issues in the Bay Area – I’m NOT trying to sell 

anything. 

If needed: The survey should take no more than 15 minutes to complete. 

If needed: If now is not a convenient time, can you let me know a better time so I can call 

back? 

If the person says they are an elected official or is somehow associated with the survey, 

politely explain that this survey is designed to the measure the opinions of those not closely 

associated with the study, thank them for their time, and terminate the interview. 

Section 2: Screener for Inclusion in the Study 

For statistical reasons, I would like to speak to the youngest adult male currently at home 

that is at least 18 years of age. If there is no male currently at home that is at least 18 years 

of age, then ask: Ok, then I’d like to speak to the youngest female currently at home that is at 

least 18 years of age. 

If there is no adult currently available, then ask for a callback time. 

NOTE: Adjust this screener as needed to match sample quotas on gender & age

SC1

To begin, what is the zip code of your residence? 

Read zip code back to respondent to confirm before submitting. Terminate those that 

fall outside District. 

Data on File Record 5 digit zip code 

SC2 County of Residence [2,625] 

 1 Santa Clara 24% 

 2 San Francisco 13% 

 3 San Mateo 11% 

 4 Marin 4% 

 5 Sonoma 5% 

 6 Solano 6% 

 7 Alameda 21% 

 8 Napa 2% 

 9 Contra Costa 14% 
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

BAAQMD © 2005 Page 2 

Section 3: Heating Device Use 

I’d like to begin by asking you a few questions about heating devices that you may have in 

your home. 

Q1 Do you have a: _____ in your home? If yes, ask: How many: _____s do you have in your 

home? 

Do Not Randomize

A Fireplace [2,625]

None 41% 

One 50% 

Two 7% 

Three or more 1% 

B Pellet stove [2,625]

None 94% 

One 6% 

Two 0% 

Three or more 0% 

C Woodstove [2,625]

None 94% 

One 6% 

Two 0% 

Three or more 0% 

If Q1.1a, Q1.1b AND Q1.1c = (2,98), skip to Q24 

Only ask Q2 if Q1.1a = 1, otherwise skip to instructions preceding Q3. 
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

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Q2 What type of fuel do you primarily use in your fireplace – Wood, natural gas, propane or 

some other fuel? If ‘other’, ask: what type? [1,547] 

 1 Wood 47.7% 

 2 Natural gas 15.8% 

 3 Propane 0.6% 

 4 Duraflame log 5.9% 

 5 Presto log 1.6% 

 6 Other manufactured log 2.4% 

 7 Scrap wood 0.8% 

 8 Electric 0.7% 

 9 Never use fireplace 21.0% Skip to Q7 

 10 Wood + Gas 0.1% 

 11 Pellets 0.3% 

 12 Other 0.1% 

 13 Not sure 2.6% 

 14 Refused 0.5% 

Only ask Q3 if (Q1.1a = 1 and Q2 = 1) or (Q1.1c = 1) , otherwise skip to introduction 

preceding Q7 

Q3 What type of wood do you typically burn? [813] 

 1 Ash 0.5% 

 2 Eucalyptus 3.1% 

 3 Oak 38.7% 

 4 Pine (cedar) 9.5% 

 5 Walnut 1.3% 

 6 Hardwood (general) 0.8% 

 7 Fruitwood (general) 0.8% 

 8 Fir 0.3% 

 9 Almond 3.5% 

 10 Whatever available / Mixed 2.3% 

 11 Other 0.4% 

 12 Not sure 38.0% 

 99 Refused 0.8% 
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

BAAQMD © 2005 Page 4 

Q4 Do you typically purchase your wood from a wood supplier, the local store, or do you 

gather your own wood? [813] 

 1 Wood supplier 22% 

 2 Local store 32% 

 3 Gather own wood 35% 

 4 Other 7% 

 98 Don’t Know 3% 

 99 Refused 1% 

Q5 Do you tend to burn dry, seasoned wood or wood that is fresh-cut and somewhat moist? 

[813] 

 1 Dry, seasoned wood 85% 

 2 Fresh-cut & moist 5% 

 98 Don’t Know 9% 

 99 Refused 0% 

Q6

When you use your fireplace or woodstove, which of the following would you say is the 

primary reason you do so? For heating your home, or for the ambiance of having a fire? 

[813] 

 1 Heat 46% 

 2 Ambiance 50% 

 98 Don’t Know 3% 

 99 Refused 0% 

For the next series of questions, when I refer to “winter” I mean the months of November 

through February. 

Only ask Q7 for each appliance where Q1.1 = 1 

Q7 Will you use your _____ this winter? 

Do Not Randomize Yes No Not Sure Refused 

A Fireplace [1,547] 60% 38% 3% 0% 

B Pellet stove [170] 72% 25% 2% 2% 

C Woodstove [165] 74% 21% 4% 0% 

Only ask Q8 for each appliance where Q7 = 2. 
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

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Q8 Why do you not expect to use your _____ this winter? Do Not Read Responses. Multiple 

Responses OK.

Do Not Randomize Air Quality 

Reasons 

Too Much 

Hassle 

Heath 

Reasons Other 

A Fireplace [581] 8% 34% 8% 56% 

B Pellet stove [42] 3% 21% 0% 76% 

C Woodstove [35] 9% 36% 3% 56% 

Only ask Q9 if [Q2 = (1,4,5,6 or 7) AND Q7a = 1], Q7b = 1 or Q7c = 1. Otherwise, skip to 

Q24. 

Q9 How often do you expect to burn wood this winter? At least once per week or less often 

than that? If unsure, ask them to estimate. [864] 

 1 At least once per week 49% Skip to Q11 

 2 Less often than once per week 48% Ask Q10 

 98 Don’t Know 2% Skip to Q12

 99 Refused 0% Skip to Q12

Q10 Would you say that you will burn wood about two to three times per month, once per 

month, or less often than once per month? If unsure, ask them to estimate. [416] 

 1 Two to three times per month 38% Skip to Q12

 2 Once per month 35% Skip to Q12

 3 Less often than once per month 24% Skip to Q12

 98 Don’t Know 2% Skip to Q12

 99 Refused 1% Skip to Q12

Q11 In a typical winter week, how many days do you expect to burn wood? If unsure, ask 

them to estimate. [423] 

 1 One day 19% 

 2 Two days 24% 

 3 Three days 21% 

 4 Four days 9% 

 5 Five days 6% 

 6 Six days 2% 

 7 Seven days 15% 

 98 Don’t Know 4% 

 99 Refused 0% 
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

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Q12 Did you burn wood in the past seven days? [864] 

 1 Yes 43% Ask Q13 

 2 No 57% Skip to Q14 

 98 Don’t Know/No opinion 0% Skip to Q14

 99 Refused 0% Skip to Q14

Q13 Did you burn wood yesterday or last night? [372] 

 1 Yes 50% 

 2 No 49% 

 98 Don’t Know/No opinion 0% 

 99 Refused 0% 

Q14 In a typical day that you burn wood, how many hours of the day do you have a fire 

burning? If unsure, ask them to estimate. [864] 

One or two 26% 

Three or four 53% 

Five or more 21% 

Q15 In a typical day that you burn wood, how many logs do you burn throughout the entire 

day? If unsure, ask them to estimate. [864] 

One or two 34% 

Three to five 34% 

Six or more 32% 

Section 4: Changes in Wood Burning Behavior 

Only ask Q16 if [Q2 = (1,4,5,6 or 7) AND Q7a = 1], Q7b = 1 OR Q7c = 1. 

 Otherwise, skip to Q24. 

Q16 This winter, do you expect that you will burn wood more often, less often, or about the 

same frequency as you did last winter? [864] 

 1 More often 22% Ask Q17 

 2 Less often 16% Skip to Q21

 3 About the same 56% Skip to Q21

 98 Don’t Know/No opinion 6% Skip to Q21

 99 Refused 0% Skip to Q21
Questionnaire & Toplines

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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

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Q17 Why are you burning wood more frequently this year? Don’t read choices. [190] 

 1 Price of gas/Energy costs/Wood is 

cheaper/More affordable 47% Ask Q18 

 2 Other 52% Skip to Q21 

 98 Don’t Know/No opinion 1% Skip to Q21 

 99 Refused 0% Skip to Q21 

Q18 How often did you burn wood last winter? At least once per week or less often than 

that? If unsure, ask them to estimate. [89] 

 1 At least once per week 62% Skip to Q20 

 2 Less often than once per week 37% Ask Q19 

 98 Don’t Know 1% Skip to Q21

 99 Refused 0% Skip to Q21

Q19

Last winter, would you say that you burned wood about two to three times per month, 

once per month, or less often than once per month? If unsure, ask them to estimate.

[33] 

 1 Two to three times per month 55% Skip to Q21

 2 Once per month 26% Skip to Q21

 3 Less often than once per month 19% Skip to Q21

 98 Don’t Know 0% Skip to Q21

 99 Refused 0% Skip to Q21

Q20 Last winter, how many days did you burn wood in a typical week? If unsure, ask them to 

estimate. [56] 

 1 One day 40% 

 2 Two days 13% 

 3 Three days 7% 

 4 Four days 24% 

 5 Five days 1% 

 6 Six days 2% 

 7 Seven days 7% 

 98 Don’t Know 4% 

 99 Refused 0% 

Q21 Ok, back to this winter. Were there occasions this winter when you normally would have 

burned wood, but decided not to? [864] 

 1 Yes 29% Ask Q22 

 2 No 66% Skip to Q24

 98 Don’t Know/No opinion 5% Skip to Q24

 99 Refused 0% Skip to Q24
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

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Q22 Why did you decide not to burn wood on these occasions? Do NOT Read Response 

Options. Multiple Responses OK. [253]

 1 

Spare the Air campaign/advertisements 

asking people not to burn wood/Don’t 

Light the Night campaign 

2% Ask Q23 

 2 Air quality reason/health reason 10% Ask Q23 

 3 Other 86% Skip to Q24 

 98 Don’t Know/No opinion 3% Skip to Q24

 99 Refused 0% Skip to Q24

Q23 So far this winter, how many times did you choose not to burn wood because of air 

quality reasons? If respondent is unsure, ask them to estimate. [31] 

 Total number of times 78 (Average of 2.52 times) 

Section 5: Awareness of Campaign 

Q24

During this winter, have you heard, read, or seen any news stories, advertisements, or 

public service announcements about Spare the Air Tonight, poor air quality, or requests 

not to use your fireplace, pellet stove, or woodstove? [2,625] 

 1 Yes 34% Ask Q25 

 2 No 65% Skip to Q26 

 98 Don’t Know/No opinion 1% Skip to Q26 

 99 Refused 0% Skip to Q26 

Q25 Where did you see or hear the news story, advertisement or public service 

announcement? Don’t read choices – multiple responses OK. [891] 

 1 Television 45% 

 2 Radio 38% 

 3 Newspaper 17% 

 4 Website 3% 

 5 Billboard 5% 

 6 E-mail/E-mail Air Alert 1% 

 7 Fax/Fax Alert 0% 

 8 Bus signs 1% 

 9 Other 5% 

 98 Don’t Know/Not Sure 7% 

 99 Refused 0% 

Only ask Q25 if interviewing the day after a Spare the Air event. Otherwise, skip to Q27. 
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

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Q26 Prior to taking this survey, were you aware that there was a “Spare the Air Tonight” 

advisory yesterday? [0] 

 1 Yes N/A 

 2 No N/A 

 98 Don’t Know/No opinion N/A 

 99 Refused N/A 

Section 6: Attitudes about Wood Smoke 

Q27 Do you think there are any negative health effects associated with breathing wood 

smoke? [2,625] 

 1 Yes 66% Ask Q28 

 2 No 23% Skip to Q29 

 98 Don’t Know/No opinion 11% Skip to Q29 

 99 Refused 0% Skip to Q29 

Q28 What are the negative health effects associated with breathing wood smoke? Don’t read 

options -- Multiple response OK [1,730] 

 1 Lung Disease – general reference 36% 

 2 Asthma 24% 

 3 Allergies 5% 

 4 Bronchitis 3% 

 5 Cancer 9% 

 6 Emphysema 4% 

 7 Chemicals/Carcinogens/Toxins in wood 12% 

 8 Carbon monoxide 10% 

 9 Other health issue 21% 

 98 Don’t Know/No opinion 17% 

 99 Refused 0% 

Q29

Different neighborhoods in the Bay Area experience different levels of air pollution from 

wood smoke. In your opinion, does your neighborhood periodically experience air 

pollution from wood smoke? [2,625] 

 1 Yes 18% Ask Q29 

 2 No 74% Skip to Section 7 

 98 Don’t Know/No opinion 8% Skip to Section 7 

 99 Refused 0% Skip to Section 7 
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Bay Area Air Quality Management District Winter Spare the Air Survey March 2006 

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Q30 Would you say that periodic air pollution from wood smoke in your neighborhood is a 

big problem, medium problem or a small problem? [464] 

 1 Big problem 6% 

 2 Medium problem 23% 

 3 Small problem 69% 

 98 Don’t Know/No opinion 2% 

 99 Refused 0% 

Section 7: Willingness to Change Heating Device 

If Q1.1a, Q1.1b AND Q1.1c = (2, 98), skip to Section 8. 

Only ask Q31 if Q1b = 1 or Q1c = 1. Otherwise, skip to instruction preceding Q32. 

Q31 Is your woodstove or pellet stove EPA certified? If necessary: Most woodstoves and 

pellet stoves manufactured after 1992 are EPA certified, while older ones are not. [328] 

 1 Yes, EPA certified 59% Skip to Section 8 

 2 No, not EPA certified 13% Go to Q32 

 98 Don’t Know 28% Go to Q32 

 99 Refused 0% Skip to Section 8

Only ask Q32 if (Q2 = 1,4,5,6 or 7) or (Q1b = 1 AND Q31 = 2, 98) or (Q1c = 1 AND Q31 = 2, 

98). Otherwise, skip to Section 8. 

Q32

Gas fireplaces and EPA certified woodstoves, inserts or pellet stoves burn much cleaner 

and are less polluting than traditional fireplaces or old woodstoves. Would you be 

willing to replace your traditional fireplace, non-EPA certified woodstove or pellet stove 

with a gas fireplace? [913] 

 1 Yes 27% 

 2 No 63% 

 98 Don’t Know/No opinion 10% 

 99 Refused 0% 

Q33 Would you be willing to replace your traditional fireplace, non-EPA certified woodstove 

or pellet stove with an EPA certified woodstove or pellet stove? [913] 

 1 Yes 34% 

 2 No 56% 

 98 Don’t Know/No opinion 11% 

 99 Refused 0% 

If Q32 = 1 OR Q33 = 1, skip to Section 8. Otherwise, askQ34. 
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Q34

There is a government sponsored program that offers rebates to residents who replace 

their traditional fireplace or non-EPA certified woodstove or pellet stove with a gas 

fireplace or EPA certified woodstove or pellet stove. If you knew that you could receive a 

rebate of: _____ dollars, would you participate in this program? [511] 

If respondent says ‘yes’, record ‘yes’ for all higher dollar amounts and go to Section 8.

Do Not Randomize Yes No Not Sure/Don’t 

Know Refused 

A 200 10% 71% 19% 0% 

B 300 13% 68% 19% 0% 

C 400 16% 64% 20% 0% 

D 500 23% 59% 18% 0% 

Section 8: Santa Clara County Program Awareness 

Only ask questions in this section if SC2 = 1. Otherwise, skip to Section 9. 

Q35

Santa Clara County has a program to offer residents a rebate for replacing a traditional 

fireplace with a gas burning fireplace or an EPA certified fireplace, woodstove or pellet 

stove. 

In the past three months, have you heard, read or seen any news stories, 

advertisements or public service announcements about this program? [637] 

 1 Yes 6% 

 2 No 93% 

 98 Don’t Know/No opinion 1% 

 99 Refused 0% 

Section 9: Marin County Program Awareness 

Only ask questions in this section if SC2 = 4. Otherwise, skip to Section 10. 

Q36

Marin County has a program to offer residents a rebate for replacing a traditional 

fireplace with a gas burning fireplace or an EPA certified fireplace, woodstove or pellet 

stove. 

In the past three months, have you heard, read or seen any news stories, 

advertisements or public service announcements about this program? [109] 

 1 Yes 4% 

 2 No 96% 

 98 Don’t Know/No opinion 0% 

 99 Refused 0% 
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Section 10: Policy Attitude 

Q37

Local governments throughout the Bay Area are considering a policy that would require 

all new housing construction to use only gas fireplaces or EPA certified fireplace inserts, 

woodstoves or pellet stoves. 

Would you support or oppose this policy? [2,625] 

 1 Support 61% 

 2 Oppose 24% 

 98 Don’t Know/No opinion 15% 

 99 Refused 0% 

Q38

In some areas, local governments have a policy that prohibits wood burning on nights 

when air pollution is expected to reach unhealthy levels. 

Would you support or oppose a policy like this in your area? [2,625] 

 1 Support 74% 

 2 Oppose 19% 

 98 Don’t Know/No opinion 7% 

 99 Refused 0% 

Q39

In some areas, local governments require that when a home that contains an older 

woodstove is sold to a new owner, the stove must be removed -- or replaced with a new 

stove or fireplace that causes less pollution. 

Would you support or oppose a policy like this in your area? [2,625] 

 1 Support 50% 

 2 Oppose 40% 

 98 Don’t Know/No opinion 10% 

 99 Refused 0% 

Section 11: BAAQMD and Spare the Air Tonight Name Recognition 

Q40 Let’s change gears a bit. Have you ever heard of the _____? Code ‘Not sure’ as ‘No’.

[2,625] 

Randomize Yes No 

A Bay Area Air Quality Management District 56% 44% 

B Spare the Air Tonight Campaign 46% 54% 

Only ask Q41 and Q42 for each item in Q40 that respondent had heard of. 
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Q41

Generally speaking, would you say you have a favorable or unfavorable opinion of the 

_____, or do you have no opinion either way? Get answer and ask: Would that be very or 

somewhat favorable / unfavorable? 

Very

Favorable 

Somewhat 

Favorable 

Neutral/ 

No Opinion 

Either Way 

Somewhat 

Unfavorable 

Very

Unfavorable 

Not Sure 

(Don’t 

Read)

A Bay Area Air Quality Management District 

[1,466] 20% 31% 38% 3% 4% 4% 

B Spare the Air Tonight Campaign [1,218] 32% 32% 26% 2% 3% 5% 

Q42 In the past six months, have you heard, read, or seen any news stories, advertisements, 

or public service announcements about the ______? 

 Yes No Unsure 

A Bay Area Air Quality Management District 

[1,466] 35% 58% 6% 

B Spare the Air Tonight Campaign [1,218] 43% 51% 6% 

Section 12: Background/Demographics 

Thank you so much for your participation. I have just a few background questions for 

statistical purposes. 

D1

Do you ever burn wood in non-winter months, between March and October? If no, 

record. If yes, ask: Which months during this period to you tend to burn wood? Check 

all months that apply. [2,625] 

 1 March 7% 

 2 April 5% 

 3 May 4% 

 4 June 5% 

 5 July 5% 

 6 August 4% 

 7 September 4% 

 8 October 6% 

 9 No 83% 

 98 Don’t Know 3% 

 99 Refused 1% 

D2 Including yourself, how many licensed drivers live in your household? [2,625] 

None 3% 

One 24% 

Two 49% 

Three or more 21% 

Refused 2% 
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D3 In what year where you born? Recoded to age. [2,625] 

18 to 24 11% 

25 to 34 21% 

35 to 44 22% 

45 to 54 18% 

55 to 64 10% 

65 and over 14% 

Refused 5% 

D4 Do you live in an apartment, condo, townhome, single-family detached home, or mobile 

home? [2,625] 

 1 Apartment 21% 

 2 Condo 6% 

 3 Townhome 8% 

 4 Single-family detached home 60% 

 5 Mobile home 2% 

 99 Refused 4% 

D5 Approximately how many years ago was your home built? [2,625] 

 1 0 to 10 years 11% 

 2 11 to 20 years 14% 

 3 21 to 30 years 13% 

 4 31 to 40 years 13% 

 5 41 to 50 years 10% 

 6 Over 50 years 27% 

 98 Don’t Know 11% 

 99 Refused 2% 

D6

This last question is for statistical purposes only. As I read the following income 

categories, please stop me when I reach the category that best represents your 

household’s total annual income before taxes. [2,625] 

 1 Under $50,000 21% 

 2 $50,000 to $74,999 16% 

 3 $75,000 to $99,999 15% 

 4 $100,000 to $149,999 17% 

 5 $150,000 to $199,999 6% 

 6 $200,000 or more 7% 

 7 Not sure or Refused (Don’t read) 18% 
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Those are all of the questions that I have for you! Thanks very much for participating. This 

survey is sponsored by the Bay Area Air Quality Management District. 

Post-Interview Items 

D7 Gender [2,625] 

 1 Male 48% 

 2 Female 52% 

D8 Day Type (day prior to interview) [2,625] 

Weekday 69% 

Weekend 22% 

Holiday 9%