E

C

/R Incorporated Providing Environmental Technical Support Since 1989

501 Eastowne Dr., Suite 250  Chapel Hill, North Carolina 27514

Telephone: (919) 484-0222  Fax: (919) 484-0122

MEMORANDUM

DATE: February 2, 2015

SUBJECT: Baseline and NSPS Emissions from Small and Large Forced-Air Furnaces

FROM: Jill Mozier, EC/R Incorporated

TO: Docket ID Number EPA-HQ-OAR-2009-0734

1.0 PURPOSE

This memorandum separates estimated emissions from small and large forced-air furnaces at 

baseline and assuming implementation of the final NSPS for Residential Wood Heaters. 

We estimate, based on industry discussions with EPA, that 25% of current forced-air furnace 

sales are of small forced-air furnaces (those with less than 65,000 BTU/hr heat output) and 75% 

of current sales are of large forced-air furnaces (those with 65,000 BTU/hr heat output or larger).

These percentages were used to separate estimated emissions from the forced-air furnace 

appliance category as a whole into emissions from small and large forced-air furnaces. 

The emissions memorandum1and the supporting cost effectiveness spreadsheets2use the same 

percentages in the spreadsheet formulas to estimate NSPS emissions in 2016 (when small forcedair furnaces – an estimated 25% of forced-air furnace shipments – must meet the Step 1 limit) 

and in 2017 (when large forced-air furnaces – an estimated 75% of shipments – must also meet 

the Step 1 limit). Separate rows for small and large forced-air furnaces are presented in the 

following tables and in the Regulatory Impact Analysis (RIA).

The following tables are numbered according to how they appear in the RIA, which is available 

in the docket for this rulemaking.

 

1 Memorandum to USEPA from EC/R Inc. Estimated Emissions from Wood Heaters. January 2015.

2

See January 2015 cost effectiveness (CE) spreadsheets including for PM2.5 the Revised Wood Heater NSPS PM CE 

7%, for VOC the Revised Wood Heater NSPS VOC CE 7%, and for CO the Revised Wood Heater NSPS CO CE 7%. 

All of these spreadsheets are found in the public docket for this rulemaking.
Table 4-3. NSPS Adjusted Emission Factors for PM2.5 – Baseline, Step 1 PM Emission Limits and Step 2 PM Emission Limits

Emission Inventory Category

Baseline 

Emission 

factor 

(lb/ton)

Baseline 

Emissions 

(tons)

Baseline 

Tons/appl

Step 1* 

Emission 

Factor

Step 1* 

Emissions 

(tons)

 Step 1* 

Tons/appl

2020 

Step 2 

Emission 

Factor 

2020 

Step 2 

Emissions 

(tons)

2020 

Step 2 

Tons/appl

Woodstove: fireplace inserts; EPA 

certified; non-catalytic 8.76 5,371 0.0041 8.76 5,371 0.0041 3.89 2,387 0.0018

Woodstove: fireplace inserts; EPA 

certified; catalytic 9.72 2,023 0.0047 9.72 2,023 0.0047 7.78 1,618 0.0038

Woodstove: freestanding, EPA 

certified, non-catalytic 8.76 6,745 0.0077 8.76 6,745 0.0077 3.89 2,998 0.0034

Woodstove: freestanding, EPA 

certified, catalytic 9.72 3,769 0.0101 9.72 3,769 0.0101 7.78 3,016 0.0081

Woodstove: pellet-fired, general 3.06 1,798 0.0021 3.06 1,798 0.0021 1.36 799 0.0009

Single Burn Rate Stoves 30.6 71,424 0.0324 8.76 20,447 0.0093 3.89 9,088 0.0041

Hydronic heater: outdoor 64 116,933 0.3208 6.4 11,693 0.0321 2.00 3,654 0.0100

Furnace: indoor, cordwood (all) 64 83,972 0.2392 16 20,993 0.0598 2.00 2,624 0.0075

Furnace: indoor, cordwood (small) 64 20,993 0.2392 16 5,248 0.0598 2.00 656 0.0075

Furnace: indoor, cordwood (large) 64 62,979 0.2392 16 15,745 0.0598 2.00 1,968 0.0075

* Step 1 standard becomes effective in 2015 for all appliances, except forced-air furnaces have work practice/operational standards beginning 

on the 2015 effective date; Step 1 emission limits for small furnaces become effective in 2016; and Step 1 emission limits for large furnaces 

become effective in 2017. 

0.0060 Baseline woodstove weighted average (Tons/appl)

0.0060 2015 Step 1 woodstove weighted average (Tons/appl)

0.0034 2020 Step 2 woodstove weighted average (Tons/appl)
ted Annual Shipments by Category, 2008-2020

8 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

27 80,851 77,617 79,169 80,752 82,367 84,015 85,695 87,409 89,157 100,000 102,000 104,040

00 25,560 24,538 25,028 25,529 26,039 26,560 27,091 27,633 28,186 28,750 29,325 29,911

81 83,313 79,981 81,581 83,212 84,876 86,574 88,305 90,072 91,873 93,710 95,585 97,496

00 26,199 25,151 25,654 26,167 26,690 27,224 27,769 28,324 28,891 29,468 30,058 30,659

50 6,550 6,288 6,414 6,542 6,673 6,806 6,942 7,081 7,223 7,367 7,514 7,665

50 19,649 18,863 19,241 19,625 20,018 20,418 20,827 21,243 21,668 22,101 22,543 22,994

85 8,553 8,211 8,375 13,100 13,362 13,629 13,902 14,180 14,463 14,753 15,048 15,349

ted PM2.5 Emissions (Tons): Baseline

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

563 360 345 352 359 367 374 381 389 397 445 454 463

1,295 827 794 810 826 843 860 877 895 912 931 949 968

83 53 51 52 53 54 55 56 57 59 60 61 62

9,808 6,267 6,017 6,137 6,260 6,385 6,513 6,643 6,776 6,911 7,049 7,190 7,334

2,452 1,567 1,504 1,534 1,565 1,596 1,628 1,661 1,694 1,728 1,762 1,798 1,834

7,356 4,700 4,512 4,603 4,695 4,789 4,884 4,982 5,082 5,183 5,287 5,393 5,501

3,520 2,250 2,160 2,203 3,446 3,514 3,585 3,656 3,730 3,804 3,880 3,958 4,037

5,269 9,757 9,367 9,554 10,944 11,163 11,386 11,614 11,846 12,083 12,365 12,612 12,865
4

Table 4-6. Estimated PM2.5 Emissions (Tons): NSPS

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Wood Stoves 563 360 345 352 359 367 374 381 389 397 445 454 259

Single Burn Rate 

Stoves 1,295 827 794 810 826 843 860 251 256 261 266 272 123

Pellet Stoves 83 53 51 52 53 54 55 56 57 59 60 61 28

Furnace: indoor, 

cordwood (all) 9,808 6,267 6,017 6,137 6,260 6,385 6,513 6,643 5,505 1,728 1,762 1,798 229

Furnaces - small 2,452 1,567 1,504 1,534 1,565 1,596 1,628 1,661 423 432 441 449 57

Furnaces - large 7,356 4,700 4,512 4,603 4,695 4,789 4,884 4,982 5,082 1,296 1,322 1,348 172

Hydronic Heating 

Systems 3,520 2,250 2,160 2,203 3,446 3,514 3,585 366 373 380 388 396 126

Total 15,269 9,757 9,367 9,554 10,944 11,163 11,386 7,697 6,581 2,825 2,922 2,980 765
5

Table 4-4. NSPS Adjusted Emission Factors for VOC – Baseline, Step 1 PM Emission Limits and Step 2 PM Emission Limits

Emission Inventory Category

Baseline 

Emission 

factor 

(lb/ton)

Baseline 

Emissions 

(tons)

Baseline 

Tons/appl

Step 1* 

Emission 

Factor

Step 1* 

Emissions 

(tons)

 Step 1* 

Tons/appl

2020 

Step 2 

Emission 

Factor 

2020 

Step 2 

Emissions 

(tons)

2020 

Step 2 

Tons/appl

Woodstove: fireplace inserts; EPA 

certified; non-catalytic 12 7,357 0.0056 12 7,357 0.0056 5.33 3,270 0.0025

Woodstove: fireplace inserts; EPA 

certified; catalytic 15 3,121 0.0073 15 3,121 0.0073 12.00 2,497 0.0058

Woodstove: freestanding, EPA 

certified, non-catalytic 12 9,240 0.0106 12 9,240 0.0106 5.33 4,107 0.0047

Woodstove: freestanding, EPA 

certified, catalytic 15 5,817 0.0155 15 5,817 0.0155 12.00 4,654 0.0124

Woodstove: pellet-fired, general 0.041 24 0.0000 0.041 24 0.0000 0.02 11 0.0000

Single Burn Rate Stoves 53 123,709 0.0561 12 28,010 0.0127 5.33 12,449 0.0056

Hydronic heater: outdoor 67.4 123,145 0.3378 6.74 12,314 0.0338 2.11 3,848 0.0106

Furnace: indoor, cordwood (all) 67.4 88,433 0.2519 16.85 22,108 0.0630 2.11 2,764 0.0079

Furnace: indoor, cordwood (small) 67.4 22,108 0.2519 16.85 5,527 0.0630 2.11 691 0.0079

Furnace: indoor, cordwood (large) 67.4 66,325 0.2519 16.85 16,581 0.0630 2.11 2,073 0.0079

0.0086 Baseline woodstove weighted average (Tons/appl)

0.0086 2015 Step 1 woodstove weighted average (Tons/appl)

0.0049 2020 Step 2 woodstove weighted average (Tons/appl)

* Step 1 standard becomes effective in 2015 for all appliances, except forced-air furnaces have work practice/operational standards beginning 

on the 2015 effective date; Step 1 emission limits for small furnaces become effective in 2016; and Step 1 emission limits for large furnaces 

become effective in 2017. 
6

Table 4-9. Estimated VOC Emissions (Tons): Baseline*

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Wood Stoves 803 513 493 502 512 523 533 544 555 566 635 647 660

Single Burn Rate 

Stoves 2,243 1,433 1,376 1,403 1,431 1,460 1,489 1,519 1,549 1,580 1,612 1,644 1,677

Pellet Stoves 1 1 1 1 1 1 1 1 1 1 1 1 1

Furnace: indoor, 

cordwood (all) 10,329 6,600 6,336 6,463 6,592 6,724 6,859 6,996 7,136 7,278 7,424 7,572 7,724

Furnaces - small 2,582 1,650 1,584 1,616 1,648 1,681 1,715 1,749 1,784 1,820 1,856 1,893 1,931

Furnaces - large 7,747 4,950 4,752 4,847 4,944 5,043 5,144 5,247 5,352 5,459 5,568 5,679 5,793

Hydronic Heating 

Systems 3,707 2,369 2,274 2,320 3,629 3,701 3,775 3,851 3,928 4,006 4,086 4,168 4,251

Total 17,083 10,916 10,480 10,689 12,165 12,409 12,657 12,910 13,168 13,431 13,758 14,033 14,313

Table 4-10. Estimated VOC Emissions (Tons): NSPS* 

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Wood Stoves 803 513 493 502 512 523 533 544 555 566 635 647 376

Single Burn Rate 

Stoves 2,243 1,433 1,376 1,403 1,431 1,460 1,489 344 351 358 365 372 169

Pellet Stoves 1 1 1 1 1 1 1 1 1 1 1 1 0

Furnace: indoor, 

cordwood (all) 10,329 6,600 6,336 6,463 6,592 6,724 6,859 6,996 5,798 1,820 1,856 1,893 241

Furnaces - small 2,582 1,650 1,584 1,616 1,648 1,681 1,715 1,749 446 455 464 473 60

Furnaces - large 7,747 4,950 4,752 4,847 4,944 5,043 5,144 5,247 5,352 1,365 1,392 1,420 181

Hydronic Heating 

Systems 3,707 2,369 2,274 2,320 3,629 3,701 3,775 385 393 401 409 417 133

Total 17,083 10,916 10,480 10,689 12,165 12,409 12,657 8,269 7,097 3,145 3,265 3,330 919
7

Table 4-5. NSPS Adjusted Emission Factors for CO – Baseline, Step 1 PM Emission Limits and Step 2 PM Emission Limits

Emission Inventory Category

Baseline 

Emission 

factor 

(lb/ton)

Baseline 

Emissions 

(tons)

Baseline 

Tons/appl

Step 1* 

Emission 

Factor

Step 1* 

Emissions 

(tons)

 Step 1* 

Tons/appl

2020 

Step 2 

Emission 

Factor 

2020 

Step 2 

Emissions 

(tons)

2020 

Step 2 

Tons/appl

Woodstove: fireplace inserts; EPA 

certified; non-catalytic 140.8 86,323 0.0662 140.8 86,323 0.0662 62.6 38,366 0.0294

Woodstove: fireplace inserts; EPA 

certified; catalytic 104.4 21,725 0.0509 104.4 21,725 0.0509 83.5 17,380 0.0407

Woodstove: freestanding, EPA 

certified, non-catalytic 140.8 108,418 0.1241 140.8 108,418 0.1241 62.6 48,186 0.0552

Woodstove: freestanding, EPA 

certified, catalytic 104.4 40,486 0.1082 104.4 40,486 0.1082 83.5 32,389 0.0866

Woodstove: pellet-fired, general 15.9 9,344 0.0110 15.9 9,344 0.0110 7.1 4,153 0.0049

Single Burn Rate Stoves 230.8 538,716 0.2442 140.8 328,645 0.1489 62.6 146,064 0.0662

Hydronic heater: outdoor 360 657,748 1.8042 36 65,775 0.1804 11.3 20,555 0.0564

Furnace: indoor, cordwood (all) 360 472,341 1.3456 90 118,085 0.3364 11.3 14,761 0.0421

Furnace: indoor, cordwood (small) 360 118,085 1.3456 90 29,521 0.3364 11.3 3,690 0.0421

Furnace: indoor, cordwood (large) 360 354,256 1.3456 90 88,564 0.3364 11.3 11,070 0.0421

0.0863Baseline woodstove weighted average (Tons/appl)

0.08632015 Step 1 woodstove weighted average (Tons/appl)

0.04582020 Step 2 woodstove weighted average (Tons/appl)

* Step 1 standard becomes effective in 2015 for all appliances, except forced-air furnaces have work practice/operational standards beginning 

on the 2015 effective date; Step 1 emission limits for small furnaces become effective in 2016; and Step 1 emission limits for large furnaces 

become effective in 2017. 
8

Table 4-13. Estimated CO Emissions (Tons): Baseline*

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Wood Stoves 8,079 5,163 4,956 5,055 5,156 5,259 5,365 5,472 5,581 5,693 6,385 6,513 6,643

Single Burn Rate 

Stoves 9,766 6,241 5,991 6,111 6,233 6,358 6,485 6,614 6,747 6,882 7,019 7,160 7,303

Pellet Stoves 432 276 265 270 275 281 287 292 298 304 310 316 323

Furnace: indoor, 

cordwood (all) 55,170 35,254 33,844 34,520 35,211 35,915 36,633 37,366 38,113 38,876 39,653 40,446 41,255

Furnaces - small 13,793 8,813 8,461 8,630 8,803 8,979 9,158 9,342 9,528 9,719 9,913 10,112 10,314

Furnaces - large 41,378 26,440 25,383 25,890 26,408 26,936 27,475 28,025 28,585 29,157 29,740 30,335 30,941

Hydronic Heating 

Systems 19,803 12,654 12,148 12,391 19,381 19,769 20,164 20,567 20,979 21,398 21,826 22,263 22,708

Total 93,249 59,586 57,203 58,347 66,256 67,582 68,933 70,312 71,718 73,152 75,194 76,698 78,232

Table 4-14. Estimated CO Emissions (Tons): NSPS*

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Wood Stoves 8,079 5,163 4,956 5,055 5,156 5,259 5,365 5,472 5,581 5,693 6,385 6,513 3,524

Single Burn Rate 

Stoves 9,766 6,241 5,991 6,111 6,233 6,358 6,485 4,035 4,116 4,198 4,282 4,368 1,980

Pellet Stoves 432 276 265 270 275 281 287 292 298 304 310 316 143

Furnace: indoor, 

cordwood (all) 55,170 35,254 33,844 34,520 35,211 35,915 36,633 37,366 30,967 9,719 9,913 10,112 1,289

Furnaces - small 13,793 8,813 8,461 8,630 8,803 8,979 9,158 9,342 2,382 2,430 2,478 2,528 322

Furnaces - large 41,378 26,440 25,383 25,890 26,408 26,936 27,475 28,025 28,585 7,289 7,435 7,584 967

Hydronic Heating 

Systems 19,803 12,654 12,148 12,391 19,381 19,769 20,164 2,057 2,098 2,140 2,183 2,226 710

Total 93,249 59,586 57,203 58,347 66,256 67,582 68,933 49,222 43,060 22,054 23,073 23,535 7,647