# 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:** January

30 , 201 5 **SUBJECT:** Estimated Emissions from Residential Wood Heaters **FROM:** Jill Mozier, EC/R Inc.

Beth Friedman, EC/R Inc. **TO:** David Cole, EPA/OAQPS

Gil Wood, EPA/OAQPS Amanda Aldridge, EPA/OAQPS The purpose of this memorandum is to present an estimate of the fine particulate matter (PM2.5 

### ), volatile organic compound (VOC) and carbon monoxide (CO) emissions from wood heater appliances based on projected sales of new units and based on emissions under the final NSPS. **I. PM Methodology**  **A. Estimating Average Emissions per Appliance**  We used the EPA Residential Wood Combustion (RWC) emission estimation tool 1 

### , which is an AccessTM database that compiles nationwide RWC emissions using county level, process specific data and calculations. We summed the nationwide number of appliances and total tons of wood burned for each of the relevant emission inventory categories (Table 1) in the inventory . **Table 1. RWC Emission Inventory Categories Used** Woodstove: fireplace inserts; EPA certified; non- catal ytic Woodstove: fireplace inserts; EPA certified; cataly tic Woodstove: freestanding, EPA certified, non- cataly tic Woodstove: freestanding, EPA certified, catalytic Woodstove: pellet- fired, general Woodstove: freestanding, non- EPA certified Hydronic heater: outdoor Furnaces: indoor, cordwood

1 Emission factors are based on EPA's Residential Wood Combustion Tool version 4.1 with updates from the 2012 EPA report (Gullett et al. Environmental, Energy Market, and Health Characterization of Wood- Fired Hydronic Heater, Final Report, June 2012) .

### 2

We then made some adjustments/assumptions to the baseline RWC inventory. First, we deleted data in the RWC database for non- certified stoves and in serts, as these cannot be sold. With the exception of wood stoves, we applied the PM2.5 

### emission factors for each class to the total tons of wood burned and calculated an average emission rate/appliance/category . In the case of wood stoves, the RWC database use s an average of all PM 10 

### AP - 42 emission factors. 2 

### The RWC database assumes that PM 10 

### and PM 2.5 

### factors are identical. At a minimum, we estimate that all new wood stoves meet the AP - 42 PM 10 

### emission factors for “Phase II” stoves (the current NSPS promulgated in 1988) and therefore started with the lower AP - 42 Phase II emission factors for cataly

tic and non- catal ytic stoves at baseline , rather than the higher average of all AP - 42 emission factors used in the RWC database . Furthermore , to avoid any potential for overstating baseline emissions, we went a step further and assumed that all new shipments will meet the current Washington State limits, which are approximately 40 percent less than the 1988 NSPS Phase II limits . We therefore used baseline emission factors which are 60 percent of the AP - 42 Phase II emission factors

– less than half the value use d in the RWC to represent the average of all AP - 42 emission factors

– in order to ensure a forward- looking and understated baseline. Second, we estimated that outdoor hydronic heaters and indoor hydronic heaters have the same emission profile. Single burn rate stoves are not included in the RWC database as separate identifiable units. We estimated that they

would have the same baseline emission factor as freestanding non- certified wood stoves, i.e., 30.6 lb/ton of wood burned. We used the average tons burned per appliance factor as representative of these stoves as well. We used this subset of the RWC database to calculate a baseline average emission rate/appliance (or “emission inventory

category”), including an adjustment of the RWC emission factor to the current Washington State limits for currently certified wood stoves, as discussed above . We multiplied the total tons of wood burned for the appliance b y the RWC emission factor (adjusted as appropriate) to calculate the total tons of PM 2.5 

### emissions. We divided this value b y the number of appliances in the category to calculate the baseline average PM 2.5 

### emissions per individual appliance (Table 2).

2 AP - 42, Chapter 1.10, Residential Wo od Stoves, Table 1.10 - 1. See: http://www.epa.gov/ttnchie1/ap42/ch01/final/c01s10.pdf .

### 3 **Table 2. PM 2.5**  

### Tons per Appliance Estimate (Baseline)

*Non - EPA certifi ed wood stove emission factor and tons/appliance were used to represent single burn rate stoves. 

### The next step was to develop emission factors representing the final NSPS . The NSPS limits used in this analysis are based on phased - in compliance dates, or “steps”, for subcategories of appliances. Subpart AAA will regulate “room heaters” and includes adjustable burn rate stoves, single burn rate stoves, and pellet stoves. Subpart QQQQ will regulate “central heaters” and includes outdoor and indoor hydronic heaters and forced- air furnaces. Following is a summary of the current NSPS implementation assumptions for appliances within the regulated subcategories . The final NSPS is a phased standard with compliance dates of 201 5 and 2020 for all appliances . In addition , forced - air furnaces will have a Step 1 PM emission limit for small forced- air furnaces in 2016 and for large forcedair furnaces in 2017 , as discussed below. The Step 2 PM emission limit compliance date is 20 20 for all appliances. **Subpart AAA** (“room heaters”):

Adjustable burn rate, single burn rate, and pellet stoves : **Step 1 PM emission**  **limit** of 4.5 g/hr upon promulgation in 201 5 ; and **Step 2 PM emission**  **limit** of 2.0 g/hr five years after promulgation in 20 20 . **Note** : The Step 1 limit is the 1995 Washington State standard for non catal ytic stoves; and the Step 2 limit is already met by the top performing catalytic, noncatal ytic and pellet stove models . Specificall y, this industry data from 2010 indicate that approximately 90% (130 out of 145 catal ytic, non- catal ytic and pellet stoves combined) already meet the Step 1 limit. 3 

### We expect that manufacturers will focus on existing models that meet the Washington State limits in order to comply with the Step 1 standard. Furthermore, certification data indicate that 26 % of non- cataly tic and cataly

tic stoves combined and 70% of pellet stoves already meet the Step 2 standard . 4 

### Although previously unregulated and a less developed technology than adjustable burn rate stoves, single burn rate

3 Final HPBA Heater Database version 2/25/10, EC/R received from Bob Ferguson for HPBA on 4/26/10 4 Memorandum to USEPA from EC/R, Inc. Derivation of wood heater model percentages meeting Step 2 standards . November 2014. 

### Emi **ssi on Inve**  **ntory Ca te**  **gor y**  **Polluta nt**  **Bas elin**  **e Emi**  **ssi on**  **fa ctor**  **(lb /ton)**  **Base lin**  **e**

**Emi ssions**  **(t ons)**  **Base lin**  **e**

**To ns/** **appl** Wo odstove : fir epl ace i nse rts; EP A ce rt ified ; noncatal yti c Pr im aryP M2. 5 8. 76 5, 371 0. 0041 Wo odstove : fir epl ace i nse rts; EP A ce rt ified ; catal yt ic Pr im aryP M2. 5 9. 72 2, 023 0. 0047 Wo odstove : frees tandi ng, EP A ce rti fied , non- cat al yt ic Pr im aryP M2. 5 8. 76 6, 745 0. 0077 Wo odstove : frees tandi ng, EP A ce rti fied , catal yti c Pr im aryP M2. 5 9. 72 3, 769 0. 0101 Wo odstove : pe llet -fired , ge ne ral Pr im aryP M2. 5 3. 06 1, 798 0. 0021 Si ngl e Burn Rate S tove s* Pr im aryP M2. 5 30. 6 71, 424 0. 0324 Hy droni c h ea te r: o utdoor Pr im aryP M2. 5 64 116, 933 0. 3208 Furnace : i ndoor, cordw ood Pr im aryP M2. 5 64 83, 972 0. 2392

### 4

stove designs have been undergoing R&D in anticipation of the proposed NSPS and cleaner designs are nearly market-ready. 5 

### Subpart QQQQ (“central heaters”):

 Hydronic heaters (both outdoor and indoor) : **Step 1 PM emission**  **limit** of 0.32 lb/mm BTU heat output (weighted average and an 18 g/hr cap for each individual test run) upon promulgation in 201 5 ; and **Step 2 PM emission**  **limit** of 0. 1 0 lb/mm BTU heat output (at each burn rate) five ye ars after promulgation in 20 20 . **Note** : The Step 1 limit is identical to the EPA “Phase 2” voluntary program limit and is therefore already met b y all 50 of the 50 currentl y Phase 2 qualified hydronic heater models built by U.S. manufacturers participating in the voluntary

program . Inaddition, there are 19 qualification tests that have been recently submitted to EPA and, if valid, are all expected to be added to the Phase 2 qualification list very soon. The Step 2 limit is already met by 9 of the 50 (18%) hydronic heater models built by U.S. manufacturers participating in the voluntary program 6 

### , as well as over 100 European manufacturers per test method EN 303 - 05. 7 

### Itshould be noted that to - date cleaner models continue to become Phase 2 qualified and additional manufacturers not participating in the voluntary program may

also have models meeting Step 1 and Step 2. We assume that 1 8 % of existing hydronic heaters can meet the Step 2 limit without intensive R&D efforts .  Forced-Air Furnaces: Work practice/operational standards will be required of all forced- air furnaces upon the rule’s 2015 effective date. A **Step 1 PM emission**  **limit** of 0.93 lb/mm BTU heat output will be required b y 2016 (1 year after the 2015 effective date) for small forced - air furnaces (<65,000 BTU/hr models, representing approximately 25% of current sales) and this same limit of 0.93 lb/mm BTU will be required b y 2017 (2 years after the 2015 ef fective date) for large forced- air furnaces (≥65,000 BTU/hr models, representing approximately

75% of current sales). A **Step 2 PM emission**  **limit** of 0. 1 5 lb/mm BTU heat output will be required for all forced- air furnace models five years after promulgation in 20 20 . **Note** : The phased timelines are based on the technological and economic limitations of testing and certifying approximately 50 previously untested forced

–air furnaces in the 60 days between signature and the effective date and also on industry comments on the proposed rule, explaining the design challenges for small and large forced- air furnaces, respectively. The Step 1 PM emission limits and the Step 2 PM emission limits are based on test data from development of the Canadian standard B415.1 - 10 8 

### , conversation s with industry regarding cleaner forced- air furnace models currently being tested in R&D 9 

### and comments on the proposed rule. Forced- air furnace designs able to meet the Step 2 PM emission limit are expected to be based on technology transferred from hydronic heater designs and/or wood stove designs . 5 2/8/13 telephone discussion between Gil Wood, USEPA, and a manufacturer of single burn rate stoves. 6 See list of cleaner hydronic heaters participating in EPA’s P hase 2 voluntary Hydronic Heater P rogram at http://www.epa.gov/burnwise/owhhlist.html . 7 European Wood- Heating Technology Survey: An Overview of Combustion Principles and the Energy and Emissions Performance Characteristics of Commercially Available Systems in Austria, Germany, Denmark, Norway, and Sweden; Final Report; Prepared for the New York State Energy Research and Development Authority; NYSERDA Report 10

–01; April 2010. 8 CSA B415.1 - 10, Performance Testing of Solid - Fuel - Burning Heating Appliances. Appendix D. March 2010. 9 2/8/13 telephone discussion between Gil Wood, USEPA, and a manufacturer of forced- air furnaces.

### 5

We developed adjusted emission factors to reflect the limits discussed above, which were then used to calculate new average tons of emissions per appliance for each RWC appliance type in Tables 1 and 2. Adjustments were assumed for NSPS emission factors (as noted below) in order to not over state emission reductions . Actual emission reductions may be greater than reductions resulting from our emission factor adjustments for the purpose of this analysis. Following is a description of how the RWC factors were adjusted for each appliance type .  Woodstove: all EPA certified . As noted above, we determined the ratio of emissions between the existing 1988 NSPS limits compared to the Washington S tate standards . For both catalytic and non- cataly tic devices, the Washington standard is 60% of the 1988 NSPS . We assumed this same ratio would apply to the emission factors and multiplied the RWC emission factor (for Phase II certified models) by 60% . We used these adjusted RWC emission factors (shown in Table 2) as both baseline and Step 1 PM emission factors for catal ytic and non- catal ytic stoves . It should be noted that the assumption that at baseline all wood stoves already meet the Washington S tate standards may slightly underestimate baseline emissions, as not 100% of wood stoves currently sold do meet the Washington S tate standards. We made this simplifying assumption in order to avoid any potential for overstating baseline emissions. Furthermore, w e estimated that the Step 1 PM emission factor was the same as the baseline emission factor, because , as noted above, approximately 90% of current wood stove models already meet the Step 1 PM limit according to industry data. 10 

### F or the Step 2 PM emission factor for non- catal ytic models, we scaled the Step 1 PM emission factor by the ratio of the Step 2 PM limit to the Step 1 PM limit (or 2.0/4 .5 = 0. 44 ). Again, in order to not overstate emission reductions, for catalytic models, we scaled the Step 1 PM emission factor b y the ratio of the Step 2 PM limit to the Washington State PM standard for catalytic stoves (or 2.0/2.5 = 0.8). For consistency with our shipment data (described in section B) and because the RWC database provides four separate emission factors for cataly tic and non- catal ytic, freestanding models and fireplace inserts, we used the weighted average value for all four wood stove ty

pes to represent the total population of adjustable burn rate wood stoves . Finally, we multiplied the resulting PM emission factors by the total tons burned for the appliance type (provided by the RWC database) and then divided that by the appliance population (also provided by the RWC database) to derive the tons/appliance of PM 2.5 

### emissions. The emission factors and tons/appliance are shown in the green rows in Table 3.  Woodstove: pellet fired, general . We used the RWC emission factor shown in Table 2 as both the baseline and Step 1 PM emission factor for pellet stoves because nearly all current pellet stove models already meet the Step 1 PM standard according to industry data. 1 0 

### For the Step 2 PM emission factor, we scaled the Step 1 PM emission factor by the ratio of the Step 2 PM limit to the Step 1 PM limit (or 2.0/4 .5 = 0. 44 ). We multiplied the resulting emission factors b y the total tons burned for pellet stoves and then divided that by the pellet stove appliance population to derive the tons/appliance of PM 2.5 

### emissions. The emission factors and tons/appliance are shown in the orange row in Table 3.

10 Final HPBA Heater Database version 2/25/10, EC/R received from Bob Ferguson for HPBA on 4/26/10

### 6

 Woodstove: freestanding, non- EPA certified (single burn rate stoves) . As described above, we assumed that the freestanding non- EPA certified wood stove emission inventory category includes the population of single burn rate stoves. We therefore used the RWC emission factor for freestanding non- EPA certified wood stoves (30.6 lb/ton) as the baseline emission factor for single burn rate stoves. For the Step 1 PM emission factor, we used the same emission factor as a certified non- catal ytic stove meeting the Washington S tate PM standards (i.e., 8.76 lb/ton) because the same standard is being proposed for single burn rate stoves as for adjusta

ble burn rate stoves. Likewise, w e used the same emission factor used for noncatal ytic stoves for the Step 2 PM emission factor. We multiplied the resulting emission factors b y the total tons burned for this appliance category and then divided that by

the appliance population to derive the tons/appliance of PM 2.5 

### emissions. The emission factors and tons/appliance are shown in the grey row in Table 3.  Hydronic heater: outdoor/indoor . As noted above, we estimated that indoor hydronic heaters (a minority

of the hydronic heater population) have the same emission profile as the outdoor hydronic heater appliance category provided in the RWC. According to the EPA voluntary hydronic heater program, the “Phase 2” heaters that are presumed to represent the Step 1 limit are 90% cleaner than older unqualified units , as determined in laboratory tests on crib wood . 11 

### We estimate that the majority of the existing inventory is represented by

these unqualified units, and applied a 90% reduction to the RWC baseline emission factor shown in Table 2 ( 64 lb/ton) in order to derive the Step 1 PM emission factor (of 6.4 lb/ton). F or the Step 2 PM emission factor, we scaled the Step 1 PM emission factor by the ratio of the Step 2 PM limit to the Step 1 PM limit (or 0. 10/0. 32 = 0. 31 ). We multiplied the resulting emission factors b y the total tons burned for the hydronic heater RWC appliance category and then divided that by

the hydronic heater appliance population to derive the tons/appliance of PM 2.5 

### emissions. The emission factors and tons/appliance are shown in the blue row in Table 3.  Furnace: indoor, cordwood . At baseline, we estimated that forced- air furnaces have the same updated emission factor as hydronic heaters ( 64 lb/ton) , consistent with the fact that hydronic heaters and forced- air furnaces have the same emission factor in version 4.1 of EPA’s RWC tool. 12 

### For the Step 1 PM emission factor, we scaled the baseline emission factor by 75% (to 16 lb/ton) because background material provided in the Canadian standards review process stated that that the emission limit associated with this method would result in an approximately

75% reduction in emissions compared to a non- qualifying furnace. 13 

### We estimate that the Step 2 PM emission limit of 0.15 lb/mm BTU (based on cord wood , c onsistent with the test method) is roughly equivalent to the hydronic heater crib wood-based limit of 0.10 lb/mm BTU. We also estimate that the baseline emission factor for each appliance category is the same ; therefore we used the same Step 2 PM emission factor for forced - air furnaces as used for hydronic heaters ( 2.00 lb/ton). We multiplied the emission factors b y the total tons burned for the cordwood furnace RWC appliance category and then

11 See the EPA Burn Wise Website regarding the Hydronic Heater Voluntary Program : http://www.epa.gov/burnwise/participation.html . 12 Emission factors are based on EPA's Residential Wood Combustion Tool version 4.1 with updates from the 2012 EPA report (Gullett et al. Environmental, Energy Market, and Health Characterization of Wood- Fired Hydronic Heater, Final Report, June 2012 ). 13 CSA B415.1 - 10, Performance Testing of So lid - Fuel - Burning Heating Appliances. Appendix D. March 2010.

### 7

divided that by

the furnace appliance population to derive the tons/appliance of PM 2.5 

### emissions. The emission factors and tons/appliance are shown in the lavender row in Table 3. Table 3 shows the baseline, Step 1 PM emission factor and Step 2 PM emission factor for each appliance type resulting from our assumption s and adjustments described above. We used the appropriate tons/appliance with annual shipment data (Section B) to estimate annual PM 2.5 

### emissions (Section C), based on the phased emission reduction dates.8



### Table 3. NSPS Adjusted Emission Factors for PM**2.5** 

### – **Baseline, Step 1 PM Emission Limits**  **and Step 2 PM Emission Limits** 

*For forced - air furnaces, the compliance dates are 2015 for work practice/operational standards, 2016 for the Step 1 PM emission limit for small furnaces and 2017 for the Step 1 PM emission limits for large furnaces . **Emi ssi**  **on Inve ntory Cate**  **gory Poll**  **utant Bas**  **elin e**  **Emi ssion**  **fa ctor**  **(lb/ ton)**  **Bas elin**  **e Emi**  **ssions (t**  **ons) Base**  **line**

**To ns/** **ap pl**  **2015***

**Ste p 1**  **Emi ssion**  **Fa ctor**  **2015***

**Ste p 1**  **Emi ssions**  **(t ons)**  **2015***

**Ste p**  **1 Tons/appl**  **2020**

**Ste p**  **2 Emi**  **ssion Fa**  **ctor 2020** 

**Ste p 2**  **Emi ssions**  **(t ons)**  **2020**

**Ste p 2**  **To ns/** **ap pl**  Woodstove : f irepla ce i nse rts; EP A ce rti fied; n on-catal yti c Pr im aryP M2 .5 8. 76 5, 371 0. 0041 8. 76 5, 371 0. 0041 3. 89 2, 387 0. 0018 Woodstove : f irepla ce i nse rts; EP A ce rti fied; catal yti c Pr im aryP M2 .5 9. 72 2, 023 0. 0047 9. 72 2, 023 0. 0047 7. 78 1, 618 0. 0038 Woodstove : f re es tandi ng, EP A ce rti fied, non-catal yti c Pr im aryP M2 .5 8. 76 6, 745 0. 0077 8. 76 6, 745 0. 0077 3. 89 2, 998 0. 0034 Woodstove : f re es tandi ng, EP A ce rti fied, catal yti c Pr im aryP M2 .5 9. 72 3, 769 0. 0101 9. 72 3, 769 0. 0101 7. 78 3, 016 0. 0081 Woodstove : pe llet -fired , ge ne ral Pr im aryP M2 .5 3. 06 1, 798 0. 0021 3. 06 1, 798 0. 0021 1. 36 799 0. 0009 Si ng le Burn Rate Stove s Pr im aryP M2 .5 30. 6 71, 424 0. 0324 8. 76 20, 447 0. 0093 3. 89 9, 088 0. 0041 Hydroni c h ea te r: o utdoor Pr im aryP M2 .5 64 116, 933 0. 3208 6. 4 11, 693 0. 0321 2. 00 3, 654 0. 0100 Furnace : indoor, co rdw ood* Pr im aryP M2 .5 64 83, 972 0. 2392 16 20, 993 0. 0598 2. 00 2, 624 0. 0075



### 0. 0060 Base lin e woodstove w eig hte d av erage ( To ns/appl ) 0. 0060 2015 S te p 1 woodstove w eig hte d av erage ( To ns/appl ) 0. 0034 2020 S te p 2 woodstove w eig hte d av erage ( To ns/appl )

### 9

**B. Shipment Data**  **, Model Design Lifespan and Emitting Lifespan** We used data in the Frost & Sullivan Market (F&S) report 14 

### on 2008 shipments by product category, and F&S revenue forecasts which incorporated the weak economy in years 2009 and 2010, to calculate the reduced number of shipments in years 2009 and 2010. Forced air furnaces were outside the scope of the F&S report. In stead, we used manufacturer estimates of total industry

sales in 2008 15 

### and applied the F&S market factors to estimate shipments through 2010. The F&S wood stove numbers included both certified and non- certified stoves, so we estimated numbers of non- certified stove shipments out of the total reported wood stove category (i.e., 40,000 single burn rate stoves shipped in 2008). 1 5 

### These shipments were deleted from the total wood stove category shipments. We expanded the 2008 single burn rate estimate using the F&S factors. For ye ars 2011 through 20 29 estimated shipments are generally based on a forecasted revenue growth rate of 2.0%, in keeping with the average annual growth in real GDP predicted by the US Bureau of Economic Analysis . 16 

### There is not a perfect correlation between shipments and revenue (for example, because of their higher unit cost, pellet stoves generate more abso lute revenue than wood stoves), but we think the overall trend in the projection is reasonable in the absence o f specific shipment projections. The only exceptions to the use of a 2.0% GDP -based growth rate are for ye ars 2012 and 2018, in which we used industry estimates for hydronic heater and wood stove shipments, respectively. For ye ar 2012, an HPBA consultant estimated there were 13,100 baseline hydronic heater sale s. 17 

### For ye ar 2018, the same HPBA consultant projected there to be 100,000 wood stove sale s. 18 

### We adjusted our estimated shipment data accordingl y. (It should be noted that these two industry estimates are slightly

higher than the estimates for those ye ars would be based on the 2.0% GDP -based growth rate; but over the entire anal ys is period, using the predicted GDP growth rate as a basis is appropriate.) Table 4 on the next page shows a truncated summary of the shipment data through year 2023. Our cost effectiveness analysis (CE) 19 

### assumes a 1 0 - ye ar model design lifespan as well as a 20 - year u se/emitting appliance lifespan. These assumptions were made to best characterize the actual model design and use lifespans . For proposal , we used a 20 - ye ar model design lifespan, reasoning that many models developed for the 1988 NSPS are still being sold ( after 25 ye ars), with many

“new” models retaining the same internal working parts with merely exterior cosmetic changes . Respectful of comments on the proposed rule 20 

### , however, in which some

14 Market Research and Report on North American Residential Wood Heaters, Fireplaces, and Hearth Heating Products Market. Prepared by Frost & Sullivan. April 26, 2010. P. 31 - 32. 15 NSPS Review and Comments. Confidential Business Information submitted by manufacturer. September 2010. 16 Global Economic Outlook 2014, projections prepared by the Conference Board , May 201 4 update ; http://www.conference -board.org/data/globaloutlook.cfm 17 Cost- Effectiveness Analysis of Alternative Hydronic Heater New Source Performance Standards, prepared for the Hearth, Patio, and Barbecue Association by NERA Economic Consulting, May 2014. (Attachment 3 of HPBA’s comment to the Docket EPA - HQ - OAR- 2009 - 0734 ) 18 Cost- Effectiveness Analysis of Alternative Woodstove New Source Performance Standards, prepared for the Hearth, Patio, and Barbecue Association by NERA Economic Consulting, May 2014. (Attachment 2 of HPBA’s comment to Docket EPA- HQ - OAR- 2009 - 0734 ) 19 Memorandum to USEPA from EC/R, Inc. Residential Wood Heater Cost Effectiveness Analysis. January, 201 5 . 20 Comments on the proposed NSPS are available electronically through http://www.regulations.gov by searching Docket IDs EPA - HQ - OAR- 2009 - 0734.

### 10

industry representatives commented that a shorter model lifespan i s more accurate, we reduced our assumed model design lifespan to 10 years for this analysis . Regarding the emitting lifespan of the appliance, most wood heaters in consumer homes emit for at least 2 0 years and often much longer. Therefore our CE anal ys is tracks shipments through year 20 29 (assuming a 1 0 - ye ar design life for a model meeting the Step 2 limit in year 20 20 ) and emissions through ye ar 2048 (assuming a 20 - ye ar emitting life for an appliance shipped in ye ar 2029) . Table 4 is a truncated summary of our actual shipment data which extended through years 20 29 . See the CE analys is spreadsheets 21 

### for the complete shipment data. **C. Estimated PM** **2.5** 

### Emissions from Shipments of New Appliances As described above, we calculated the average emissions per appliance typ e using the emission factor for each category multiplied by

the inventory

value of total tons of wood burned divided by

the number of appliances in the inventory population. This tons/appliance value was then multiplied by

the number of shipments to calculate total emissions from each appliance category per year under baseline conditions, i.e., in the absence of an NSPS. In order to not overstate potential emission reductions, baseline emissions were discounted by the percentage of appliances already

meeting the Step 2 PM emission limit s (i.e., the 26% of wood stoves, 7 0% of pellet stoves, and 1 8 % of hydronic heaters estimated to already m eet Step 2 PM emission limits , as noted in subsection A). Table 5 on the next page shows a truncated summary of the estimated PM 2.5 

### emissions (in tons) under baseline conditions through year 2023. We then estimated emissions under the NSPS (Table 6) based on the phase d- in timeline for each appliance. The emission estimates assume that the total number of shipped units meet the PM emission limit in the year the PM emission limit is required . As noted above, we discounted NSPS emissions by the percentage of appliances already meeting the Step 2 PM emission limit. Tables 5 and 6 show emission estimates out to ye ar 2023 under baseline and NSPS scenarios . Like Table 4, these are truncated summaries. Our CE anal ys is tracks emission reductions out through 20 48 , assuming a 10 - ye ar design life for a model meeting each phased- in (stepped) limit, and assuming that stoves shipped in the 1 0 th 

### ye ar of design life will be emitting in homes for another 20 ye ars. The CE analysis 22 

### incorporates “trailing emissions” as part of our 20 - ye ar emitting lifespan assumption. For example, our anal ys is estimates that a stove shipped in 201 5 will emit in homes for 20 ye ars – or until 203 4 (inclusive of both 201 5 and 20 34 ). We therefore drop emissions from this stove in our anal ys is in year 203 5 . Likewise, we drop emissions for a stove shipped in 201 6 in year 203 6 , and so on. The CE anal ys is spreadsheets show all years of emission data, under both baseline and NSPS scenario s , as well as cumulative PM 2.5 

### emission reduction s through year 20 48 . Spreadsheets are provided for appliances regulated under Subpart AAA “Room Heaters” (i.e., wood stoves, pellet stoves, and single burn rate stoves ), as well as for appliances under Subpart QQQQ “Central Heaters” (i.e., forced air furnaces and hydronic heaters ) . The CE anal ys is 2 2 

### also includes a spreadsheet showing cumulative emissions and emission reductions for Subparts AAA and QQQQ combined . 21 See January 2015 cost effectiveness (CE) spreadsheets including for PM 2.5 the Revised Final Wood Heater NSPS PM CE 7% for the CE analysis supporting the NSPS . All of these spreadsheets are found in the public docket for this rulemaking . 22 Memorandum to USEPA f rom EC/R, Inc. Residential Wood Heater Cost Effectiveness Analysis. January, 2015.11



### Table 4. Estimated Annual Shipped Units

**Table 5. Estimated PM 2.5**  

### Emissions (Tons) **– Baseline**  **Scenario** *****

* Estimates are reduced for the percentage of appliances assumed to already meet the Step 2 PM emission limit (26% of wood stoves, 70% of pellet stoves and 18% of hydronic heaters) , in order to not overstate emission reductions attributable to this NSPS.

**2008 2009**  **2010 2011**  **2012 2013**  **2014 2015**  **2016 2017**  **2018 2019**  **2020 2021**  **2022 2023**  Wood St ove s 126, 527 80, 851 77, 617 79, 169 80, 752 82, 367 84, 015 85, 695 87, 409 89, 157 100, 000 102, 000 104, 040 106, 121 108, 243 110, 408 Si ngl e Bur n Ra te St ove s 40, 000 25, 560 24, 538 25, 028 25, 529 26, 039 26, 560 27, 091 27, 633 28, 186 28, 750 29, 325 29, 911 30, 509 31, 120 31, 742 Pe llet St ove s 130, 381 83, 313 79, 981 81, 581 83, 212 84, 876 86, 574 88, 305 90, 072 91, 873 93, 710 95, 585 97, 496 99, 446 101, 435 103, 464 Fur na ce : in door, co rdwood 41, 000 26, 199 25, 151 25, 654 26, 167 26, 690 27, 224 27, 769 28, 324 28, 891 29, 468 30, 058 30, 659 31, 272 31, 898 32, 536 Hydr oni c Hea ti ng Sys tems 13, 385 8, 553 8, 211 8, 375 13, 100 13, 362 13, 629 13, 902 14, 180 14, 463 14, 753 15, 048 15, 349 15, 656 15, 969 16, 288

**2008 2009**  **2010 2011**  **2012 2013**  **2014 2015**  **2016 2017**  **2018 2019**  **2020 2021**  **2022 2023**  Wo od Stoves 563 360 345 352 359 367 374 381 389 397 445 454 463 472 482 491 Si ng leBurn Ra te St ove s 1, 295 827 794 810 826 843 860 877 895 912 931 949 968 988 1, 007 1, 027 Pe llet Sto ve s 83 53 51 52 53 54 55 56 57 59 60 61 62 63 65 66 Fur na ce : in door, co rd wood 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 7, 481 7, 631 7, 783 Hydr oni c He at in g Sys tems 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 4, 118 4, 200 4, 284 To ta l **15, 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**  **13, 122**  **13, 384**  **13, 652** 

### 12

**Table 6. Estimated PM** **2.5** 

### Emissions (Tons **) –**  **NSPS Scenario**  *****

* Step 1 PM emission limit in 2015 and Step 2 PM emission limit in 2020 for all appliances, except forced - air furnaces have work practice/operational standards in 2015, Step 1 PM emission limits for small furnaces in 2016, Step 1 PM emission limits for large furnaces in 2017 and Step 2 PM emission limits for all furnaces in 2020 . In order to not overstate emission reductions attributable to this NSPS, e stimates are reduced for the percentage of appli ances estimated to already meet the Step 2 PM emission limit s (26% of wood stoves, 70% of pellet stoves and 18% of hydronic heaters) . I n this analysis , emission reductions for forced - air furnaces are not quantified for the work practice/operational standar d required in 2015 , altho ug h stakeholders agree that work practice/operational standards will re duce emissions .

**2008 2009**  **2010 2011**  **2012 2013**  **2014 2015**  **2016 2017**  **2018 2019**  **2020 2021**  **2022 2023**  Wood St ove s 563 360 345 352 359 367 374 381 389 397 445 454 259 264 269 275 Si ngl e Bu rn Ra te Sto ves 1, 295 827 794 810 826 843 860 251 256 261 266 272 123 126 128 131 Pe llet Stov es 83 53 51 52 53 54 55 56 57 59 60 61 28 28 29 29 Fur na ce : in door, cordw ood 9, 808 6, 267 6, 017 6, 137 6, 260 6, 385 6, 513 6, 643 5, 505 1, 728 1, 762 1, 798 229 234 238 243 Hydr oni c He at in g Sys tems 3, 520 2, 250 2, 160 2, 203 3, 446 3, 514 3, 585 366 373 380 388 396 126 129 131 134 To ta l **15, 269**  **9, 757**  **9, 367**  **9, 554**  **10, 944**  **11, 163**  **11, 386**  **7, 697**  **6, 581**  **2, 825**  **2, 922**  **2, 980**  **765 780**  **796 812** 

### 13

**II. V** **olatile Organic Compound Methodology**  We used the same methodology described in Section Ito develop emission estimates for VOC emissions. Using the RWC database, we developed an estimate of VOC emissions per appliance u sing baseline emission factors. Then, using the same NSPS phase - in assumptions and anticipated emission reductions (i.e., that VOC reductions are comparable to PM 2.5 

### reductions), we developed emission factors , as shown in Table 7 . Next, using the same assumptions as we used for PM 2.5 

### , we calculated VOC emissions at baseline and under the NSPS scenario for each stepped limit , as shown in Tables 8 and 9 . Finally, cumulative VOC emissions and emission reductions under the NSPS were calculated based on a 10 - ye ar model design lifespan for shipments and a 20 - ye ar appliance use lifespan for emissions, as explained in Sections I- B and I - C. Although VOC emissions are not being regulated under this NSPS, estimated VOC emissions and emission reductions are provided separatel y in our CE anal ys is spreadsheets. 23 

### III. **C arbon Monoxide**  **Methodology** We used the same methodology described in Section Ito develop emission estimates for CO emissions. Using the RWC database, we developed an estimate of CO emissions per appliance u sing baseline emission factors. Then, using the same NSPS phase - in assumptions and anticipated emission reductions (i.e., that CO reductions are comparable to PM 2.5 

### reductions), we developed emission factors , as shown in Table 10 . Next, using the same assumptions as we used for PM 2.5 

### , we calculated CO emissions at baseline and under the NSPS scenario for each stepped limit, as shown in Tables 11 and 12 . Finally, cumulative CO emissions and emission reductions under the NSPS were calculated based on a 10 - ye ar model design lifespan for shipments and a 20 - ye ar appliance use lifespan for emissions, as explained in Sections I- B and I - C. Although CO emissions are not being regulated under this NSPS, estimated CO emissions and emission reductions are provided separately in our CE analys is spreadsheets . 24

23 See January 2015 cost effectiveness (CE) spreadsheets for VOC entitled Revised Final Wood Heater NSPS VOC CE 7%, available in the public docket for this rulemaking. 24 See January 2015 cost effectiveness (CE) spreadsheets for CO entitled Revised Final Wood Heater NSPS CO CE 7% , available in the public docket for this rulemaking.

### 14

**Table 7**  **. NSPS Adjusted Emission Factors for**  **Volatile Organic Compounds –**  **Baseline, Step 1 and Step 2** 

* For forced - air furnaces, the compliance dates are 2015 for work practice/operational standards, 2016 for the Step 1 PM emission limit for small furnaces and 2017 for the Step 1 PM emission limits for large furnaces . **Emi ssi**  **on Inve nt** **ory Cate gory**  **Pol lut** **ant Base**  **line Emi**  **ssion fa**  **ctor (lb/**  **ton) Bas**  **elin e**  **Emi ssions**  **(tons) Base**  **lin e** 

**Tons/appl 2015** 

**Ste p**  **1 Emi**  **ssion Fa**  **ctor 2015** 

**Ste p 1**  **Emi ssions**  **(tons) 2015** 

**Ste p**  **1 Tons/appl**  **2020**

**Ste p 2**  **Emi ssi**  **on Fa**  **ctor 2020** 

**Ste p 2**  **Emi ssi**  **ons (t** **ons) 2020** 

**Ste p**  **2 Tons/appl**  Wo odstove : fir ep la ce i nse rts; EPA ce rti fied; n on- catal ytic Vo la ti le Organi c Compounds 12 7, 357 0. 0056 12 7, 357 0. 0056 5. 33 3, 270 0. 0025 Wo odstove : fir ep la ce i nse rts; EPA ce rti fied; catal yti c Vo la ti le Organi c Compounds 15 3, 121 0. 0073 15 3, 121 0. 0073 12. 00 2, 497 0. 0058 Wo odstove : frees tandi ng, EPA ce rti fied, non-c atal yti c Vo la ti le Organi c Compounds 12 9, 240 0. 0106 12 9, 240 0. 0106 5. 33 4, 107 0. 0047 Wo odstove : frees tandi ng, EPA ce rti fied, catal ytic Vo la ti le Organi c Compounds 15 5, 817 0. 0155 15 5, 817 0. 0155 12. 00 4, 654 0. 0124 Wo odstove : pe llet -fir ed , ge ne ral Vo la ti le Organi c Compounds 0. 041 24 0. 0000 0. 041 24 0. 0000 0. 02 11 0. 0000 Single Burn Rate S toves Vo la ti le Organi c Compounds 53 123, 709 0. 0561 12 28, 010 0. 0127 5. 33 12, 449 0. 0056 Hy droni c h ea te r: outdoor Vo la ti le Organi c Compounds 67. 4 123, 145 0. 3378 6. 74 12, 314 0. 0338 2. 11 3, 848 0. 0106 Furnace : i ndoor, co rd wood Vo la ti le Organi c Compounds 67. 4 88, 433 0. 2519 16. 85 22, 108 0. 0630 2. 11 2, 764 0. 0079 

### 0. 0086 Base lin e woodstove w eig hte d av erage ( To ns/appl ) 0. 0086 2015 S te p 1 w oodstove w eig hte d av erage ( To ns/appl ) 0. 0049 2020 S te p 2 w oodstove w eig hte d av erage ( To ns/appl )

### 15

**Table 8**  **. Estimated**  **Volatile Organic Compound E missions (Tons)**  **– Baseline**  **Scenario***

**Table 9**  **. Estimated**  **Volatile Organic Compound Emissions (Tons**  **) –**  **NSPS Scenario***

* Step 1 PM emission limit in 2015 and Step 2 PM emission limit in 2020 for all appliances, except forced - air furnaces have work practice/operational standards in 2015, Step 1 PM emission limits for small furnaces in 2016, Step 1 PM emission limits for large furnaces in 2017 and Step 2 PM emission limits for all furnaces in 2020 . In order to not overstate emission reductions attributable to this NSPS, e stimates are reduced for the percentage of appliances estimated to already meet the Step 2 PM emission limits (26% of wood stoves, 70% of pellet stoves and 18% of hydronic heaters). In this analysis , emission reductions for forced - air furnaces are not quan tified for the work practice/operational standard required in 2015 , although stakeholders agree that work practice/operational standards will reduce emissions. **2008 2009**  **2010 2011**  **2012 2013**  **2014 2015**  **2016 2017**  **2018 2019**  **2020 2021**  **2022 2023**  Wood St oves 803 513 493 502 512 523 533 544 555 566 635 647 660 673 687 701 Si ngl e Bur n Ra te Stove s 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 1, 711 1, 745 1, 780 Pe llet Stove s 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Furna ce : in door, cordwood 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 7, 878 8, 036 8, 197 Hydroni c Hea ti ng Sys tems 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 4, 336 4, 423 4, 512 To ta l **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**  **14, 600**  **14, 892**  **15, 189** 

**2008 2009**  **2010 2011**  **2012 2013**  **2014 2015**  **2016 2017**  **2018 2019**  **2020 2021**  **2022 2023**  Wood St ove s 803 513 493 502 512 523 533 544 555 566 635 647 376 383 391 399 Si ngl e Bur n R ate Stove s 2, 243 1, 433 1, 376 1, 403 1, 431 1, 460 1, 489 344 351 358 365 372 169 172 176 179 Pe llet Stove s 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 Fur na ce : in door, co rdw ood 10, 329 6, 600 6, 336 6, 463 6, 592 6, 724 6, 859 6, 996 5, 798 1, 820 1, 856 1, 893 241 246 251 256 Hydr oni c Hea ti ng Sys tems 3, 707 2, 369 2, 274 2, 320 3, 629 3, 701 3, 775 385 393 401 409 417 133 136 138 141 Tota l **17, 083**  **10, 916**  **10, 480**  **10, 689**  **12, 165**  **12, 409**  **12, 657**  **8, 269**  **7, 097**  **3, 145**  **3, 265**  **3, 330**  **919 937**  **956 975** 

### 16

**Table 1**  **0 . NSPS Adjusted Emission Factors for**  **Carbon Monoxide –**  **Baseline, Step 1 and Step 2** 

* For forced - air furnaces, the compliance dates are 2015 for work practice/operational standards, 2016 for the Step 1 PM emission limit for small furnaces and 2017 for the Step 1 PM emission limits for large furnaces . **Emi ssion Inve**  **ntory Cate gory**  **Pol lu**  **tant Base**  **line Emi**  **ssion fa**  **ctor (lb** **/ton) Base**  **line**

**Emi ssions**  **(t ons)**  **Base line** 

**Tons/appl 2015** 

**Ste p**  **1 Emi**  **ssion Fa**  **ctor 2015** 

**Ste p 1**  **Emi ssions**  **(t ons)**  **2015**

**Ste p 1**  **To ns/** **appl 2020** 

**Ste p 2**  **Emi ssion**  **Factor 2020** 

**Ste p 2**  **Emi ssions**  **(t ons)**  **2020**

**Ste p 2**  **To ns/** **ap pl**  Wo odstove: firep la ce i nserts; EP A ce rti fied ; non-c atal ytic Carbon M onoxi de 140. 8 86, 323 0. 0662 140. 8 86, 323 0. 0662 62. 6 38, 366 0. 0294 Wo odstove: firep la ce i nserts; EP A ce rti fied ; catal yti c Carbon M onoxi de 104. 4 21, 725 0. 0509 104. 4 21, 725 0. 0509 83. 5 17, 380 0. 0407 Wo odstove: freest andi ng, EP A ce rti fied , non-c atal ytic Carbon M onoxi de 140. 8 108, 418 0. 1241 140. 8 108, 418 0. 1241 62. 6 48, 186 0. 0552 Wo odstove: freest andi ng, EP A ce rti fied , catal yti c Carbon M onoxi de 104. 4 40, 486 0. 1082 104. 4 40, 486 0. 1082 83. 5 32, 389 0. 0866 Wo odstove: pellet -fired , general Carbon M onoxi de 15. 9 9, 344 0. 0110 15. 9 9, 344 0. 0110 7. 1 4, 153 0. 0049 Si ngle B urn Rate S toves Carbon M onoxi de 230. 8 538, 716 0. 2442 140. 8 328, 645 0. 1489 62. 6 146, 064 0. 0662 Hy droni c he ate r: outdoor Carbon M onoxi de 360 657, 748 1. 8042 36 65, 775 0. 1804 11. 3 20, 555 0. 0564 Furnace : in door, cordwood Carbon M onoxi de 360 472, 341 1. 3456 90 118, 085 0. 3364 11. 3 14, 761 0. 0421 

### 0. 0863 Base lin e woodstove w eig hte d av erage ( To ns/appl ) 0. 0863 2015 S te p 1 woodstove w eig hte d av erage ( To ns/appl ) 0. 0458 2020 S te p 2 woodstove w eig hte d av erage ( To ns/appl )

### 17

**Table 1**  **1 . Estimated**  **Carbon Monoxide Emissions (Tons)**  **– Baseline Scenario** *

**Table 1 2**  **. Estimated Carbon Monoxide**  **Emissions (Tons) –**  **NSPS Scenario***

* Step 1 PM emission limit in 2015 and Step 2 PM emission limit in 2020 for all appliances, except forced - air furnaces have work practice/operational standards in 2015, Step 1 PM emission limits for small furnaces in 2016, Step 1 PM emission limits for l arge furnaces in 2017 and Step 2 PM emission limits for all furnaces in 2020 . In order to not overstate emission reductions attributable to this NSPS, estimates are reduced for the percentage of appliances estimated to already meet the Step 2 PM emission limits (26% of wood stoves, 70% of pellet stoves and 18% of hydronic heaters). In this analysis , emission reductions for forced - air furnaces are not quantified for the work practice/operational standard required in 2015 , although stakeholders agree that work practice/operational standards will reduce emissions.

**2008 2009**  **2010 2011**  **2012 2013**  **2014 2015**  **2016 2017**  **2018 2019**  **2020 2021**  **2022 2023**  Wo od St ove s 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 6, 776 6, 912 7, 050 Si ngl e Bur n Ra te St ove s 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 7, 449 7, 598 7, 750 Pe llet Stove s 432 276 265 270 275 281 287 292 298 304 310 316 323 329 336 342 Fur na ce : i ndoor, co rd wo od 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 42, 080 42, 922 43, 780 Hydr oni c H ea ti ng Sys tems 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 23, 162 23, 625 24, 098 To ta l **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**  **79, 796**  **81, 392**  **83, 020**