2005 residential wood combustion emissions estimates

2005 Residential Wood Combustion Emissions Estimatesbased on WSU 2001 Survey

July 19, 2007

2

Purpose of Survey: Update residential wood combustion emissions estimates Last statewide survey was done by

Bonneville Power Administration in 1990 Post-1990 woodstove sales indicated

downward trend 1990 – 2000 population growth ~ 21% Current information wanted for air

stagnation advisories, and air quality planning

3

Survey Partnership Washington, Oregon, Idaho, and Canada

were working together to develop regional emissions estimates for air quality analyses

Federal Environmental Protection Agency special project funding was available to states

WA/OR/ID combined EPA funding to make improvements to several emissions sources, including residential wood combustion

4

Survey

Social & Economic Sciences Research Center, Washington State University John Tarni, Ph.D., principal investigator Thom Allen, study director

Computer-assisted telephone interviews Trained interviewers Six call attempts, and individual scheduling Interviewer monitoring All responses were recorded. Database of coded

responses was provided.

5

Survey Sampling

Sample RegionHouseholds

w/phoneStarting Sample

Purged* Sample

Completed** Interviews

Incorporated 1,032,851 2,000 1,200 259

Unincorporated

WWA 303,592 1,000 586 165

EWA Forest 598,683 1,000 622 163

EWA Range 115,750 1,000 517 167

State 2,050,876 5,000 2,925 754

Error < 4% at 95% confidence level (3-state)

* Purge removed all known non-working and non-household phone lines** Incomplete included: refusals, unable to reach, non-working numbers, business numbers, unable to interview, FAX numbers, partial interviews

6

Survey Design Questions designed to estimate

number of households owning and using wood-burning devices

amount of wood burned by device and certification status

geographic differencesseasonal, weekday/weekend, hourly variation

Drew upon 1990 BPA survey questions Funding determined number of questions,

sampling areas, and sample size

7

Questions – Devices Owned by Type Do you have a …

fireplace without a stove insert? fireplace with a stove insert? free-standing woodstove? pellet stove? wood-fired central furnace?

Do you know when your stove or insert was purchased? (determines certification status) year (month if known), or approximately how old

If more than one device, which is used most for heating?

8

Results – Devices Owned by Type

0

100,000

200,000

300,000

400,000

500,000

600,000

Fire

plac

e

Woo

dsto

veor

Ins

ert

unce

rtifi

ed

Woo

dsto

veor

Ins

ert

cert

ified

Pel

let

Fur

nace

Incorporated Unincorporated

9

Results – Devices Owned by Type

WWA EWA forest EWA non-Forest

Fireplace 563,208 112,337 22,666 7,775 705,985

Woodstove, uncertified 57,082 93,996 10,264 1,891 163,233

Insert, certified 98,942 36,681 5,559 883 142,065

Insert, uncertified 57,082 43,559 6,842 1,387 108,870

Woodstove, certified 47,568 48,144 8,553 841 105,106

Pellet 30,444 36,681 5,987 1,849 74,961

Furnace 19,027 0 1,711 0 20,738

Total 873,354 371,398 61,582 14,625 1,320,959

Device Incorporated

Unincorporated

State Total

10

Questions - Devices Used by Type

Did you burn any cord wood last year? Did you burn any presto logs last year? Did you burn any wood pellets last year?

11

Results – Devices Used by Type

0

100,000

200,000

300,000

400,000

Fire

plac

e

Woo

dsto

veor

Ins

ert

unce

rtifi

ed

Woo

dsto

veor

Ins

ert

cert

ified

Pel

let

Fur

nace


12

Results – Devices Used by Type


Fireplace 367,227 52,729 14,968 3,614 438,539


Insert, certified 65,644 36,681 3,421 756 106,503

Woodstove, certified 45,666 43,559 8,553 841 98,618

Insert, uncertified 37,103 43,559 3,849 504 85,016

Pellet 24,736 36,681 5,132 1,849 68,398

Furnace 13,319 0 1,711 0 15,030

Total 605,068 298,036 45,331 8,825 957,261

Device Incorporated

Unincorporated

State Total

13

Questions – Amount of Wood Burned

How many cords did you burn last year?cord is 4’ x 4’ x 8’

How many presto logs did you burn last year?

How many 40-lb bags of wood pellets did you burn last year?

14

Supporting Data – Conversion to pounds burned

Wood Type W WA E WA

Cord Wood 2,607 2,788

Presto Logs 8 8

Bags of Pellets 40 40

15

Results – Wood Burned in Tons

0

100,000

200,000

300,000

400,000

500,000

Woo

dsto

veor

Ins

ert

unce

rtifi

ed

Woo

dsto

veor

Ins

ert

cert

ified

Fire

plac

e

Pel

let

Fur

nace


16

Results – Wood Burned in Tons



Woodstove, certified 109,006 164,454 32,426 1,617 307,503

Fireplace 209,704 41,199 6,569 3,736 261,208

Insert, certified 113,240 93,469 8,074 1,318 216,100

Insert, uncertified 64,005 110,994 9,083 879 184,961

Pellet 44,152 33,262 12,501 3,780 93,695

Furnace 8,901 0 17,884 0 26,786

Total 671,641 763,630 115,721 13,755 1,564,746

Device Incorporated

Unincorporated

State Total

17

Supporting Data – PM2.5 Emission Rates in pounds per ton burned

Equipment Type PM2.5 Equipment Type PM2.5

CF 30.6 PWS, not cert 8.5

FP 23.6 PWS, cert 4

INS, not cert 30.6 WS, not cert 30.6

INS, cert I, non-cat 20 WS, cert I, non-cat 20

INS, cert II, non-cat 14.6 WS, cert II, non-cat 14.6

INS, cert I, cat 19.6 WS, cert I, cat 19.6

INS, cert II, cat 16.2 WS, cert II, cat 16.2

Certified INS and WS assumes split of 71% non-catalytic and 29% catalytic per the 2002 National Emissions Inventory (EPA).

18

Results – PM2.5 Emissions Estimates in tons per year

0

1,000

2,000

3,000

4,000

5,000

6,000W

oods

tove

or I

nser

tun

cert

ified

Woo

dsto

veor

Ins

ert

cert

ified

Fire

plac

e

Pel

let

Fur

nace


19

Results – PM2.5 Emissions Estimates in tons per year


Woodstove, uncertified 1,508 3,924 357 30 5,819

Fireplace 2,014 397 63 35 2,509

Insert, uncertified 792 1,374 111 11 2,288

Woodstove, certified 660 1,025 220 10 1,915

Insert, certified 689 592 49 8 1,338

Pellet 153 127 53 14 347

Furnace 109 0 219 0 328

Total 5,925 7,439 1,072 108 14,544

Device IncorporatedUnincorporated

State Total

20

Survey Summary Statistics

WWA EWA forest EWA non-ForestHousing Units, Total 1,478,422 747,382 141,125 42,110 2,409,039 Own Wood Device 873,354 371,398 61,582 14,625 1,320,959 % Own 59% 50% 44% 35% 55% Use Wood Device 605,068 298,036 45,331 8,825 957,261 % Use 41% 40% 32% 21% 40%Tons Wood Burned 671,641 763,630 115,721 13,755 1,564,746 Tons per Device Used 1.11 2.56 2.55 1.56 1.63Tons PM2.5 5,925 7,439 1,072 108 14,544 Lbs per Device Used 19.58 49.92 47.30 24.44 30.39

Device IncorporatedUnincorporated

State Total

21

Questions – Temporal Variation

Did you use this equipment in the …winter, spring, summer, fall of 2000? (months

were specified for each season) During a typical weekday, did you use this

equipment from …6am-10am, 10am-4pm, 4pm-10pm, 10pm-6am?

During a typical weekend, did you use this equipment from …6am-10am, 10am-4pm, 4pm-10pm, 10pm-6am?

22

Results – Temporal Variation

Seasonal Activity

0% 10% 20% 30% 40% 50% 60%

Summer

Spring

Winter

Fall

EWA Range EWA Forest WWA Incorp

23

Results – Temporal Variation

Weekday and Weekend Variation

6am-10am 10am-4pm 4pm-10pm 10pm-6am

weekday weekend

24

Questions and Results – Heating Sources What is your main source of heat?

Fuel WSU01 CEN00 AHS04Electricity 44% 53% 49%Natural Gas or Propane 36% 36% 43%Wood 9% 5% 2%Oil 6% 6% 5%Other 5% 1% 1%

25

Home Heating Statistics Sources

AHS04: 2004 America Housing Survey, Seattle-Everett Metro Area (http://www.census.gov/prod/2005pubs/h170-04-60.pdf)

CEN00: 2000 Census (http://www.census.gov/Press-Release/www/2002/demoprofiles.html)

WSU01: 2001 WSU Wood burning survey

26

Observations on Estimates Strengths

activity based on local survey survey reduction process

was checked by ODEQ number of devices similar to

surveys done for PSCAA incorporated/unincorporated

and east/west differences emissions factors were

considered above average by EPA

air quality modeling results not unreasonable (explain)

Weaknesses survey generally did not ask

questions in multiple ways (verification)

required many steps to calculate emissions estimates from survey responses

may somewhat overestimate cord wood use

emission factors are based on testing done in late 1980s to 1990

inherent variability

2005 residential wood combustion emissions estimates

Documents