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Total Projected Particulate Emissions 

from New Fireplaces in the Fifth Year 

from NSPS Effective Date

Presented for the Hearth, Patio & 

Barbecue Association Fireplace Caucus 

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Purpose of the Analysis

• Compare estimated particulate emissions 

from fireplaces 5 years after the effective date 

of an NSPS to estimated particulate emissions 

from fireplaces if an NSPS that includes 

fireplaces isn’t promulgated.
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Information Needed 

1. Projected number of new housing starts.

‐ This is the primary multiplier for the overall 

analysis.

2. Percentage of new houses with fireplaces 

broken down by:

a. Gas Fireplaces

b. Wood‐burning Fireplaces

i. Those used for heating.

ii. Those used for aesthetic enjoyment.

iii. Those not used at all.

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3. Wood Fireplace Fueling Information:

a. Amount of wood used in fireplaces per year:

i. In new fireplaces used for heating.

ii. In new fireplaces used for aesthetic enjoyment.

4. Emission factors for new fireplaces:

a. “Baseline” fireplaces.

b. NSPS fireplaces (Assumed EPA Phase 2)
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Where do we get this information?

• Some of the information is available directly 

from a variety of sources of published 

literature (surveys, studies, etc.)

• Some of the information must be derived 

from more complex analyses combining 

information from multiple sources.

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Projected Number of New Housing 

Starts

• Three different approaches.

1. Assume the 10‐year average for the period from 

1996 – 2005.

2. Assume the 10‐year average for the period from 

2000 ‐2009.

3. Apply housing start recovery slope from the 

1995 – 2005 period to the 2009 housing start 

value to project the housing starts in 2016.
*Average annual housing starts for the period 2011 to 2016 based on the slope of 1995 to 2005 housing starts and an intercept based on 7

2009 housing starts.

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New Single-Family Housing 

Starts Projection Basis

Cumulative New WBFPw/oI by Use 

Category Installed from 2011 to 2016

Heating Aesthetics Not Used

’96-’05 Pre-Downturn

Ten-Year Average 112,135 700,150 378,360

’00-’09 Ten-Year Average 101,382 633,011 342,079

’95-’05 Slope + ’09 Intercept

Projected Average ’11-’16 57,167 356,944 192,892

Note: WBFPw/oI = Wood‐burning fireplaces without inserts
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Percentage of New Houses with 

Wood Fireplaces

1. From survey information:

a. Determine the percentage of new houses with 

one or more fireplaces.

b. Determine the percentage of those fireplaces 

that are gas fireplaces. 

2. Calculate the percentage of wood burning 

fireplaces by subtraction of the gas 

fireplaces.

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3. From survey information, determine the 

percentage of fireplaces used for heating.

a. Survey information combines wood and gas.

b. Apply a gas fireplace use preference factor (from 

study) to account for the increased use 

preference for gas fireplaces over wood 

fireplaces.

‐ This is needed to determine the percentage of 

fireplaces used for heating that are gas since we 

don’t have a direct estimate of gas versus wood 

usage for fireplaces used for heating.

4. Calculate the percentage of wood burning 

fireplaces used for heating by subtracting 

the gas fireplaces used for heating.
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5. Calculate the number of wood burning 

fireplaces used for aesthetic enjoyment or 

not used at all by subtraction of the wood 

burning fireplaces used for heating.

• From survey information and calculation, 

determine the percentage of wood burning 

fireplaces that are not used at all.

• By subtraction, calculate the percentage of 

wood burning fireplaces that are used for 

aesthetic enjoyment.

• From survey information, determine and 

apply a multiple fireplace per house factor.

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Fireplace Ownership 

in New Construction

(% of Single‐Family New Construction Homes,

Multiple Ownership Factor of 1.17 Not Considered in 

Chart)

Wood‐Burning Fireplace Usage 

in New Construction

(% of Wood‐Burning Fireplaces)
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Value Reference(s)*

Usable Fireplaces (2007) 50.81%† 6

Percent Gas Fireplaces (2008) 65.43% 99‐103

Calculated Usable WBFPw/oI1 17.57%† ‐

FPw/oI Used for Heating (2007) 7.7%† 6

Gas Fireplace Usage Preference Factor (2008) 1.2 110

Calculated WBFPw/oI Used for Heating2 1.65%† (9.42%)‡ ‐

Calculated WBFPw/oI Used for Aesthetics or Not Used3 15.91%† ‐

Average Percent of Unused WBFPw/oI 31.78% 104‐108, 111‐114

Calculated WBFPw/oI Not Used4 5.58%† (31.78%)‡ ‐

Calculated WBFPw/oI Used for Aesthetics5 10.33%† (58.80%)‡ ‐

Multiple Ownership Factor 1.17 108‐110

* See “References” section for full citations.

† Percent of New Construction homes 

‡ Percent of usable wood‐burning fireplaces 1 (Usable Fireplaces, New Construction) x (1 – Fraction of Gas Fireplaces)

2 (FPw/oI Used for Heating) x (1 – Fraction of Gas Fireplaces) x (Gas Fireplace Enrichment 

Factor)

3 (Usable WBFPw/oI) – (WBFPw/oI Used for Heating)

4 (Usable WBFPw/oI) x (Average Fraction of Unused WBFPw/oI) 5 (WBFPw/oI Used for Aesthetics/Not Used) – (WBFPw/oI Not Used)

Summary of Analysis/Wood Burning Fireplaces in New Construction

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Wood Burning Fireplace Fueling 

Information

1. From survey information:

a. Determine the average cordwood use for wood 

burning fireplaces used for heating.

b. Determine the average cordwood use for wood 

burning fireplaces used for aesthetic enjoyment.

2. From literature:

a. Assign the average dry mass for a cord of wood.
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Emission Factors for New Fireplaces

1. From literature, determine baseline average 

fireplace (factory built and masonry) 

emission factor for cordwood – 11.3 g/dry 

kg.

2. Assume a Voluntary Program Phase 2 

average emission factor for NSPS fireplaces –

5.1 g/dry kg.

3. Factor in wood‐wax firelog use.

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Value Reference*

Average Cordwood Use in WBFPw/oI, Heating 0.656 cords/year 117

Average Cordwood Use in WBFPw/oI, Aesthetic 0.069 cords/year 117

Average Dry Mass of Cordwood 1.23 tons/dry cord 118

Emission Factor, Cordwood, Phase II 5.1 g/kg, 5G ‐

Emission Factor, Cordwood, Baseline 11.3 g/kg, 5G 132

Firelog Percentage† 25% 110

Average Firelog Use 16 firelogs/year 116

Average Firelog Weight 4.74 lb/firelog (dry) 116

Emission Factor, Wax‐Fiber Firelog

(Emission Rate)

21.2 g/kg, 5G

(15.69 g/h) 119

*See “References” for full citations.

†Fraction of homes that use their fireplace for aesthetics and normally burn firelogs. It is 

assumed that the overwhelming majority of firelog use is aesthetic.

Summary of Wood Burning Fireplace Fueling 

Data and Emission Factors 
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5th – Year Emissions Projections

1. By calculation, project the 5th – Year 

emissions from baseline and NSPS fireplaces 

using the three housing start projections.

2. Average the three results to give the final 

values.

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New Single-Family Housing 

Starts Projection Basis

Emission 

Factor

Projected Tons of Particles 

Emitted in 2016

Heating

Wood

Aesthetics Total

Wood Firelogs*

’96-’05 Pre-Downturn

Ten-Year Average

Phase II 538 265

164

968

Baseline 1,193 588 1,945

’00-’09 Ten-Year Average

Phase II 487 240

148

875

Baseline 1,078 531 1,758

’95-’05 Slope + ’09 Intercept

Projected Average ’11-’16

Phase II 274 135

84

493

Baseline 608 300 991

Average

Phase II 433 213

132

779

Baseline 960 473 1,565

Total Particulate Emissions for New Construction Houses with 

Wood‐Burning Fireplaces without Inserts Emitted in 2016

*The wax‐fiber firelog emission factor remains the same in both emission factor 

scenarios.
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Sensitivity Analysis – Increased 

Penetration of Gas Fireplaces

• Over time, the percentage of gas fireplaces 

has been increasing. 

• Increasing the cost of wood burning fireplaces 

with the addition of emission control 

technology is likely continue or accelerate that 

trend.

• The sensitivity case evaluates the projected 

5th‐ Year emissions if the gas fireplace 

proportion of new fireplaces increases by 10 

percentage points (~65% to ~75%).

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Percentage of New Fireplaces 

that are Gas-Fired

Emission 

Factor

Projected Tons of Particles 

Emitted in 2016

Heating

Wood

Aesthetics Total†

Wood Firelogs*

65.43% Gas Fireplaces

Phase II 433 213

132

779

Baseline 960 473 1,565

75% Gas Fireplaces

Phase II 202 163 

101

466

Baseline 447 361 909

Total Particulate Emissions for New Construction Houses with 

Wood‐Burning Fireplaces without Inserts Emitted in 2016

Sensitivity Analysis, Gas‐Fired Fireplace Proportion of New Fireplaces 

Increased from 65.43% to 75%

*The wax‐fiber firelog emission factor remains the same in both emission factor 

scenarios.

†Total values based on average of new single‐family housing starts projections as shown 

in previous table.