Fine particulate matter (PM) and organic speciation of fireplace emissions

Article abstract of DOI:10.1021/es981006f

This paper presents a summary of fireplace particle size and organic speciation data gathered to date in an ongoing project. Tests are being conducted in a residential wood combustion (RWC) laboratory on three factory- built fireplaces. RWC wood smoke particles <10 μm (PM10) consist primarily of a mixture of organic compounds that have condensed into droplets; therefore, the size distribution and total mass are influenced by temperature of the sample during its collection. During the series 1 tests (15 tests), the dilution tunnel used to cool and dilute the stack gases gave an average mixed gas temperature of 47.3 °C and an average dilution ratio of 4.3. Averages for the PM2.5 (particles <2.5 μm) and PM10 fractions were 74 and 84%, respectively. For the series 2 tests, the dilution tunnel was modified, reducing the average mixed gas temperatures to 33.8 °C and increasing the average dilution ratio to 11.0 in tests completed to date. PM2.5 and PM10 fractions were 83 and 91%, respectively. Since typical winter time mixed gas temperatures would usually be less than 10 °C, these size fraction results (even from the series 2 tests) probably represent the lower bound; the PM10 and PM2.5 size fractions might be higher at typical winter temperatures. The particles collected on the first stage (cutpoint ? 11.7 μm) were light gray and appeared to include inorganic ash. Particles collected on the remainder of the stages were black and appeared to be condensed organics because there was noticeable lateral bleeding of the collected materials into the filter substrate. Total particulate emission rates ranged from 10.3 to 58.4 g/h; corresponding emission factors ranged from 3.3 to 14.9 g/kg of dry wood burned. A wide range of Environmental Protection Agency (EPA) Method 8270 semivolatile organic compounds were found in the emissions; of the 17 target compounds quantified, major constituents are phenol, 2-methylphenol, 4- methylphenol, 2,4-dimethylphenol, and naphthalene. An account is given on fireplace particle size and organic speciation data gathered to date in an ongoing project. Total particulate matter emission rates and the results of analyses for semivolatile organics in the emissions are discussed.

Full text of DOI:10.1021/es981006f

Environ. Sci. Technol. 2000, 34, 1653-1658
wood stove particle size data (2), it has been assumed that
Fine Particulate Matter (PM) and
Organic Speciation of Fireplace
Emissions
wood stove and fireplace emissions are 100% <2.5 µm. This
has led to the assumption that RWC accounts for 4-5% of
national PM2.5 emissions. Because of the uncertainty in these
data, it was decided to undertake a sampling project to firm
up the particle size data for RWC emissions and also look at
composition as a function of particle size range. Even though
the EPA’s program addressed both wood stoves and fire-
places, this paper is focused on reporting the measurement
of the particle size distribution of fireplace emissions. Also
included are total particulate matter emission rates and the
results of analyses for semivolatile organics in the emissions.
This paper is an update of material presented previously (3).
C A R O L R . P U R V I S * A N D
R O B E R T C . M C C R I L L I S
U.S. Environmental Protection Agency, Air Pollution
Prevention and Control Division (MD-63),
Research Triangle Park, North Carolina 27711
P E T E R H . K A R I H E R
ARCADIS Geraghty & Miller, 4915 Prospectus Drive,
Research Triangle Park, North Carolina 27709
Experimental Discussion
Appliances Tested. Three factory-built fireplaces were tested
in the EPA/ ARCADIS Wood Stove Laboratory. Two of them
(A and B) were standard designs typical of those installed by
builders in new homes. The third unit (C) was a low emission
design incorporating secondary air tubes similar to those
found in most current, EPA-certified noncatalytic wood
stoves. The firebox on the low emission fireplace is smaller
than in most of the conventional designs. It incorporates
secondary air, injected through three perforated, horizontal
tubes extending across the width of the firebox near its top.
All of the fireplaces were supplied with glass doors and an
adjustable damper for admitting outdoor (outside the
dwelling) air into the firebox. Fireplace B also came equipped
with a room air blower which circulated room air through
channels between the firebox metal wall exterior and the
insulated exterior surface wall.
Data from the series 1 tests, consisting of 14 test burns
and a blank, and 2 test burns from the ongoing series 2 tests
are reported in this paper. All tests basically followed the
Washington State (WA) protocol (4). Three exceptions were
as follows: (1) red oak cordwood was used for 12 series 1
tests and both series 2 tests, (2) the fireplaces rested on a
weigh scale during tests to measure burn rate, and (3)
particulates were collected following EPA Method 5G (5).
Douglas fir dimension lumber (as specified in the WA
protocol) was used for the two remaining series 1 tests:
moisture content was 30% in one and 22% in the other. The
partially seasoned oak cordwood used in series 1 tests had
an average moisture content of 34.2%. Moisture content of
the well seasoned oak cordwood for the two series 2 tests,
run to date, averaged 16.4% on a dry basis. Moisture content
was measured with a commercially available electrical
conductance meter. Each fireplace was tested under various
combinations of glass doors open and closed, with and
without outdoor air and, if so equipped, with and without
the room air circulating fan on. All test burns began with a
cold start and included three full wood loads. Wood load
weight was determined as a function of firebox area following
the WA protocol.
This paper presents a summary of fireplace particle size
and organic speciation data gathered to date in an ongoing
project. Tests are being conducted in a residential wood
combustion (RWC) laboratory on three factory-built fireplaces.
RWC wood smoke particles <10 µm (PM10) consist
primarily of a mixture of organic compounds that have
condensed into droplets; therefore, the size distribution and
total mass are influenced by temperature of the sample
during its collection. During the series 1 tests (15 tests), the
dilution tunnel used to cool and dilute the stack gases
gave an average mixed gas temperature of 47.3 °C and an
average dilution ratio of 4.3. Averages for the PM2.5
(particles <2.5 µm) and PM10 fractions were 74 and 84%,
respectively. For the series 2 tests, the dilution tunnel
was modified, reducing the average mixed gas temperatures
to 33.8 °C and increasing the average dilution ratio to
11.0 in tests completed to date. PM2.5 and PM10 fractions
were 83 and 91%, respectively. Since typical winter time
mixed gas temperatures would usually be less than 10 °C,
these size fraction results (even from the series 2 tests)
probably represent the lower bound; the PM10 and PM2.5
size fractions might be higher at typical winter temperatures.
The particles collected on the first stage (cutpoint ≈ 11.7 µm)
were light gray and appeared to include inorganic ash.
Particles collected on the remainder of the stages were
black and appeared to be condensed organics because there
was noticeable lateral bleeding of the collected materials
into the filter substrate. Total particulate emission rates
ranged from 10.3 to 58.4 g/h; corresponding emission factors
ranged from 3.3 to 14.9 g/kg of dry wood burned. A wide
range of Environmental Protection Agency (EPA) Method
8270 semivolatile organic compounds were found in
the emissions; of the 17 target compounds quantified,
major constituents are phenol, 2-methylphenol, 4-methylphe-
nol, 2,4-dimethylphenol, and naphthalene.
Total Particulate Matter Sam pling. Emission sampling
began when the stack temperature reached 25 °C above
ambient and stopped when the stack temperature had fallen
to 25 °C above ambient after loading the third wood load.
All emissions from the fireplace stack were collected in a
dilution tunnel that meets EPA’s Method 5G specification.
Shown schematically in Figure 1, the dilution system was
modified between series 1 and series 2 tests to allow the
introduction of cooled, air-conditioned air into the tunnel
immediately downstream of the inlet. In series 2 tests to
date, the procedure has been to inject the maximum amount
of cooled air while maintaining sufficient air flow through
Introduction
In 1995, EPA estimated that residential wood combustion
(RWC), including fireplaces, accounted for 0.83% of PM10
emissions and 12% of air toxics (1). Based on very limited
* Corresponding author phone: (919)541-7519; fax: (919)541-7885;
e-mail: purvis.carol@epa.gov.
9
10.1021/es981006f Not subject to U.S. Copyright. Publ. 2000 Am . Chem . Soc.
Published on Web 03/31/2000
VOL. 34, NO. 9, 2000 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 1 6 5 3

TABLE 1. Fireplace EPA Method 5H Particulate Matter, Stack CO and CO , and XAD-2 Semivolatile Organic Test Results
2
stack gases,b
method 5H
equivalentb
g/kg dry
wood
test no./
fireplace code
dilution tunnel wood moisture, dry burn wet wood
XAD-2 semivolatile
temp, °C
% H O dry basis rate, kg/h weight,a kg g/h g/kg dry wood
CO
CO
organics,b g/kg dry wood
2
2
1/A
2/A
3/A
4/A
5/A
6/B
7/B
8/B
43.9
40.3
41.9
43.3
46.9
50.3
49.4
54.2
50.5
19.5
37.2
42.1
43.9
48.8
69.1
32.4
35.1
34.2
34.2
34.2
34.2
34.2
34.2
34.2
34.2
34.2
3.81
3.62
3.66
3.85
4.60
4.44
4.18
4.96
4.71
27.0
27.0
27.7
27.4
27.2
34.1
34.2
35.4
35.2
56.13
53.80
51.56
56.13
43.55
42.61
39.90
42.20
59.05
1.62
32.82
21.25
10.75
51.46
26.01
40.00
26.88
14.74
14.86
14.08
14.56
9.46
9.60
9.54
8.50
12.54
0.39
10.19
6.63
3.26
10.29
4.24
8.21
109.9 2276.0
123.8 2132.0
100.2 2178.0
110.1 2224.0
102.0 2244.0
87.5 1894.0
87.4 1922.0
93.7 2100.0
91.4 2096.0
3.2 284.5
101.6 2071.0
87.6 2268.0
66.6 2608.0
80.3 1789.0
66.4 2431.0
72.1 2500.0
46.2 2122.0
no data
5.2
8.3
7.9
4.2
3.2
1.1
2.5
0.9
0.1
5.9
3.9
2.4
9/B
10/Bc
11/C
12/C
13/C
14/Bd
15/Bd
16/Bc
17/Bc
34.2
34.2
34.2
30.0
22.0
17.4
15.4
3.22
3.20
3.30
5.00
6.14
4.87
7.29
22.2
21.0
21.2
23.4
27.6
34.6
34.2
3.3
ANCf
ANC
ANC
3.69
a
b
Total wood burned for the test. Dry wood weight ) wet wood weight ÷ [(% H2O/100) +1]. Values have been corrected for the blank values
c
shown for Test 10. The average burn rate for all tests (4.17 kg/h) was used to determ ine the g/kg blank value (g/h ÷ kg/h ) g/kg) for Test 10.
Doublas fir 4 × 4s used for these tests. All other tests used split red oak cordwood. Series 2 tests. Tests 1-15 constitute series 1 tests. f ANC
d
e
(analysis not com pleted).
Concentrations of these gases, stack temperature, and wood
weight were recorded automatically at 1 min intervals
throughout each test.
Particle Sizing. Particle size samples were collected with
an Andersen Mark III 8-stage impactor with backup filter.
The sampler was operated at 12-20 lpm, depending on the
actual stack velocity; nozzle size was selected to give isokinetic
conditions. The sampler was located inside the dilution tunnel
aligned with the centerline, upstream of the Method 5G
sample probe. Straight nozzles were used to preclude any
size fractionation before the first impactor stage. The
impactor’s temperature was allowed to match that of the
dilution tunnel gas. Prior to a test, impactor substrates were
desiccated, weighed, and loaded into the clean sampler body.
At the conclusion of all but Test 1, the entire impactor was
placed in the desiccator for 24 h before disassembling it to
recover the substrates. The recovered substrates were
returned to the desiccator and allowed to reach constant
weight before final weighing. Test 1 substrates were recovered
at the end of the test. They were stuck to the supports and
were destroyed in the recovery process. The Andersen
sampler was not operated during the blank run.
Sem ivolatile Organic Sam pling. A module containing an
organic adsorbent, XAD-2, was placed immediately after the
Method 5G filters to collect semivolatile organics. After
exposure, the XAD-2 modules were kept in a freezer until
they could be extracted. The resin was placed in a glass
thimble which was then placed in a Soxhlet extractor.
Extraction with dichloromethane continued for 16 h. The
extracts were reduced to about 15 mR using a rotary
evaporator and then concentrated to 5 mL with a water bath
and dry nitrogen blowdown. Semivolatile organics are
defined, in this case, as all organic compounds with boiling
points between 100 and 300 °C. Sometimes referred to as
total chromatographable organics (TCOs), this range includes
all organics with carbon numbers from 8 through 16. Total
semivolatile organics were determined by injecting an aliquot
onto a gas chromatograph (GC) equipped with a flame
ionization detector (FID) following EPA Air Pollution Pre-
vention and Control Division standard methods (6). In a
separate analysis, individual target compounds were deter-
mined by injecting an aliquot of each sample onto a Hewlett-
Packard (HP) 5970 GC equipped with a HP 5970 mass
FIGURE 1. Typical fireplace test setup.
the tunnel inlet to entrap all fireplace emissions. The cooled
air flowrate is not controlled during a test. The resulting mixed
gas temperature will vary with the fireplace chimney flow
and temperature. An improved dilution tunnel is currently
under construction to allow for more accurate simulation of
real-time conditions (such as, approaching mixed gas tem-
perature of 10 °C) and to lend itself to a full characterization
for particle loss.
As noted above, total particulate emission sampling
followed EPA Method 5G. A continuous gas sample was
extracted from the stack at the 2.44 m height and sent to a
battery of analyzers to determine concentrations of carbon
monoxide (CO), carbon dioxide (CO2), and oxygen (O2).
9
1 6 5 4 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 34, NO. 9, 2000

TABLE 2. Fireplace Test Configurations
test no./
fireplace code
outdoor
air damper
glass
doors
room air
blower
1/A
2/A
3/A
4/A
5/A
6/B
7/B
8/B
closed
closed
closed
closed
open
closed
closed
open
NA
NA
NA
NA
NA
off
off
off
on
NA
NA
NA
NA
off
off
off
off
open
closed
closed
closed
closed
open
NA
open
open
closed
closed
closed
open
open
closed
closed
closed
NA
closed
closed
open
closed
closed
closed
closed
9/B
FIGURE 2. Effect of fireplace design on particle size distribution
using wet oak fuel. Average dilution tunnel temperature shown
in °C.
10/B
11/C
12/C
13/C
14/B
15/B
16/Ba
17/Ba
open
a
Series 2 tests. Tests 1-15 constitute series 1 tests.
TABLE 3. Fireplace Particle Size Data
test no./fireplace code
% < than 2.5 µm % < than 10 µm
1/A
sam ple lost
2/A
3/A
4/A
5/A
6/B
7/B
8/B
9/B
10/blank
11/C
12/C
13/C
14/B
15/B
16/B
17/B
fireplace A average
fireplace B average
fireplace C average
wet wood average
seasoned wood average
overall series 1 average
overall series 2 average
81
84
85
77
84
77
65
85
no data
76
60
64
80
46
84
82
82
75
66
76
71
74
83
89
91
92
91
91
81
66
91
no data
82
82
78
89
70
91
91
91
84
81
85
84
84
91
FIGURE 3. Particle size distribution from fireplace B burning wet
and seasoned oak and Douglas fir. Average dilution tunnel
temperature shown in °C.
e7.5 g/ kg while burning relatively wet (moisture >30%) wood
but then only in two out of three tests; fireplace B, burning
normally seasoned wood, met the e7.5 g/ kg WA standard in
Tests 15 and 17 but not in Test 16; Tests 7 and 14, burning
relatively wet oak and Douglas fir, respectively, gave com-
parable results, suggesting that wood species may not have
a great effect on emissions; fireplace test configuration did
not impact emissions significantly; and fireplace A had the
highest emission factor.
Also included in Table 1 are the emission factors for CO,
CO2, and total semivolatile organics collected in the XAD-2
resin. The particulate matter and CO emission factors
measured here are generally in the midrange of the values
published by Dasch (8), Hall and DeAngelis (9), and Cooper
(10), who investigated emissions from three fireplaces
burning several wood species, including hardwood and
softwood. Total semivolatile organics determinations for tests
15-17 have not been completed, although analysis for
individual target compounds has been completed on
Test 15.
spectrographic detector (MSD). Calibration of the GC/ MSD
used an EPA Method 8270 semivolatile working standard
prepared by Radian Corporation. Quantification employed
a five-point calibration curve.
Particle Sizing. Particle size results are presented in Table
3 and Figures 2 and 3. As noted previously, the particle size
data from Test 1 were lost; no particle size samples were
taken during the blank test (Test 10). Test 8 particle size
results look spurious, especially the PM10 percentage. The
overall averages for the relatively wet wood were 76.5 and
85.2% for the PM2.5 and PM10 fractions, respectively.
Fireplaces A and B produced about the same size distribution
when burning partially seasoned cordwood, especially if the
Test 8 PM10 value is ignored (Figure 2). Fireplace C, the
clean burning design, produced smaller fractions of PM2.5
and PM10 burning the same wood as fireplace A and B (Figure
2). Test 15, the one seasoned Douglas fir test burned in
fireplace B, produced even smaller fractions of PM2.5 and
PM10; the <2.5 µm fraction was only 46%, but note the higher
dilution tunnel temperature (Figure 3). In contrast, Tests 16
and 17, burning well seasoned oak, averaged 83 and 91%,
Results
Total Particulate Matter. Each test ran for about 8 h. No
filter changes during tests were required for either the total
particulate or particle size sampling trains. In the WA fireplace
test method, particulate emissions are reported in EPA
Method 5H equivalents. The conversion equation used in
this paper is (7)
Method 5H ) 1.619(5G)0.905
(1)
The blank-corrected Method 5G particulate results from these
tests, converted to their 5H equivalents with eq 1, are
presented in Table 1, and the fireplace test configurations
are presented in Table 2. Five observations of note are the
following: only fireplace C would meet the WA standard of
9
VOL. 34, NO. 9, 2000 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 1 6 5 5

FIGURE 4. Emission factors for target semivolatile organic compounds (Table 4) found in the XAD-2 resin catches from selected emission
tests on three factory-built fireplaces. Wet oak (34.2% moisture) cordwood used for all tests except seasoned Douglas fir (22% moisture)
4 × 4s used in Test 15.
respectively, when the dilution tunnel gas temperature was
much lower (Figure 3).
again suggesting a combustion efficiency effect. Combustion
efficiency seems to be more important than wood moisture
alone, but it is not possible to separate the two effects.
The third variable, average dilution tunnel temperature,
excluding Test 15, ranged from 37.2 to 54.2 °C (Table 1) with
an overall series 1 tests average of 45.6 °C. The dilution tunnel
temperature for Test 15, burning seasoned Douglas fir,
averaged 69.1 °C. In series 2, it was 32.4 and 35.1 °C for the
two tests run so far. As stated earlier, the impactor train was
placed in the dilution tunnel and thus collected particles at
the dilution tunnel temperature. RWC particulates (especially
the fine fraction) are thought to be dominated by condensed
organics. At the conclusion of the series 1 tests, it was
hypothesized that the much smaller percent of the fine
fraction collected while burning seasoned wood (Test 15)
was due at least in part to the fact that less of the organics
had condensed at the higher dilution tunnel temperature.
The three variables, combustion efficiency, wood mois-
ture, and dilution tunnel gas temperature, are interrelated
and appear to have affected the particle size distribution.
The CO2 to CO ratio is a relative measure of combustion
efficiency: a higher ratio means a higher efficiency. The clean-
burning design (fireplace C) burning relatively wet oak, with
an average CO2/ CO ratio of 28.5, generally produced less PM
and a smaller PM2.5 fraction compared to fireplaces A (CO2/
CO ) 20.4) and B (CO2/ CO ) 22.2) burning the same wood.
Fireplace B, burning drier wood (and with a considerably
higher CO2/ CO ratio of 40.3 compared-to-a ratio of only 22.2
burning wetter wood), produced even less fine PM on Douglas
fir but the same on seasoned oak as when burning wetter
oak. Note that, compared to fireplaces A and B burning wetter
wood, fireplace C produced less fine PM on the same fuel,
9
1 6 5 6 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 34, NO. 9, 2000

Sem ivolatile Organics. XAD-2 samples from Tests 2, 4,
8, 11, and 15 were selected for GC/ MS analysis. The results
for the target compounds are shown in Figure 4. Note that
the sums of the target compounds typically represent less
than 10% of the total semivolatile organics collected in the
resin shown in Table 1. The target compounds and other
identified compounds quantified are listed in Table 4.
Fireplace B burning relatively wet oak (34% moisture content,
dry basis) produced less semivolatile emissions than did
fireplace A burning similar wood. Surprisingly, the low
emission fireplace C produced about the same quantity of
semivolatile emissions as did fireplace A on the same fuel.
Fireplace B’s emissions dropped significantly when burning
20% moisture content Douglas fir. These data seem to indicate
again that wood moisture content plays a major role in
determining the quantity of emissions produced.
The target compounds included eight polycyclic organic
matter (POM) compounds also quantified in the literature
(11) (Table 4). A comparison of the sum of these eight POMs
from the tests reported here and those in the literature is
presented in Table 5. The data reported here for high moisture
oak are nearly an order of magnitude higher than the literature
values for seasoned oak and green pine. Seasoned fir
produced about twice the emissions compared to green pine
and about the same as for the unknown wood. Reference 11
also reports values for wood stoves; cordwood burning stoves
range from 0.171 to 0.335 g/ kg for the sum of the same eight
POMs. These data compare favorably with the results from
partially seasoned oak reported here.
TABLE 4. Target and Other Semivolatile Organic Compounds
Quantified/Identified in the Samples Collected on XAD-2 Resin
target (quantified) compounds
tentatively identified compounds
phenol
2-furancarboxaldehyde
2-m ethylfuran
2-furanm ethanol
2-butanone
ethylbenzene
1-(acetyloxy)-2-propanone
xylene
1,2-dim ethylbenzene
phenylthyne
styrene
2,5-hexanedione
benzyl alcohol
2-m ethylphenol
acetophenone
4-m ethylphenol
2,4-dim ethylphenol
naphthalenea
2-m ethylnaphthalene
acenaphthylenea
acenaphthenea
dibenzofuran
fluorenea
pinene
phenanthrenea
2-m ethyl-3-pentanone
1-(acetoxy)-2-butanone
5-m ethyl-2-furancarboxaldehyde
benzaldehyde
anthracenea
di-n-butyl phthalate
fluoranthenea
pyrenea
benzofuran
lim onene
indene
2-m ethoxyphenol
2-ethyl-phenol
2-m ethoxy-4-m ethyl-phenol
3-m ethoxy-1,2-benzenediol
4-ethyl-2-m ethoxyphenol
2,6-dim ethoxy-phenol
2-m ethoxy-4-(1-propenyl)phenol
2,6-dim ethoxyphenol
1-m ethylnaphthalene
bis(2-ethylhexyl)hexadenoic acid
a
Included in the Clean Air Act (as am ended) Section 112(c)(6) list of
16 POMs.
Discussion
A total of 16 tests and a blank were run on three factory-built
fireplaces. Twelve of these tests were conducted burning
partially seasoned oak cordwood. Two burned well seasoned
oak cordwood. Two tests burned air-dried Douglas fir dimen-
sion lumber: one test was with partially seasoned wood and
the other with normally seasoned wood. The two conven-
tional design fireplaces, currently certified to WA’s 7.5 g/ kg
standard, exceeded this level while burning higher moisture
content wood (both oak and Douglas fir). The clean burning
design fireplace burning higher moisture wood and the
conventional fireplace burning seasoned Douglas fir lumber
both met that standard. The conventional fireplace also met
the standard on one of two tests burning well seasoned oak
cordwood.
Particle size distribution also seemed to be affected by (1)
wood moisture content as it affects combustion efficiency
and (2) the gas temperature at which the sample was
collected. The PM2.5 size fraction varied from as high as 85%
while burning wetter wood to 46% burning seasoned Douglas
fir lumber, but the dilution tunnel temperature was signifi-
cantly higher in the latter case. After modifying the dilution
tunnel to reduce the mixed gas temperature, two tests were
performed burning well seasoned oak cordwood, with a
resultant average PM2.5 fraction of 83%. This indicates that
the temperature at which the particle size sample is collected
has a major impact on the measured distribution. Future
testing will focus on gathering additional data at the lower
dilution tunnel mixed gas temperature to better simulate
field operation.
TABLE 5. Comparison of POM Emissionsa from These Tests
and Literature Valuesb
these tests
literature (11)
wet seasoned seasoned green unknown
oak fir oak (9) pine (9) (10)
sum of eight POMs
com m on to both lists
0.106 0.037
0.0174 0.0184 0.0279
a
b
In g/kg dry wood burned. See Table 4 footnote a.
This hypothesis seems to be borne out by the results from
Tests 16 and 17. Burning seasoned oak, the size fractions
(PM2.5 ) 83%, PM10 ) 91%) are as high as or higher than
those measured when burning wetter fuel (Figure 3 and Table
3). This is especially significant when considering that Tests
16 and 17 realized significantly higher combustion efficiency
as evidenced by the reduction in CO causing the CO2/ CO
ratio to nearly double (Table 1). Also note, however, that
fireplace C produced a smaller PM2.5 fraction compared to
A and B when burning the wetter wood, although the average
dilution tunnel temperature was 41.1 °C, compared to 43.3
°C for all fireplace A tests and 51.1 °C for all fireplace B tests
burning wetter oak.
Thus, of the three variables, it appears that sample
collection temperature exerts the major effect on particulate
size distribution. Combustion efficiency, per se, does not
exert a major effect on particulate size distribution, but design
modifications to lower emissions do, based on these very
limited data. Future tests burning seasoned wood should
shed more light on the particle size distribution issue.
Literature values for the sum of the eight POMs common
to these tests seem low, compared to data reported here, the
latter being similar to wood stove emission levels. POM
analyses will continue, including extraction and analysis of
filter catches as well as the XAD-2 resin catches. These data,
and data collected on several wood stoves, will be reported
at a later date.
Visual observation of the substrates from the individual
impactor stages from all tests showed a consistent color trend.
The first stage substrate, cutpoint ≈ 11.7 µm, was medium
gray. The rest of the stage substrates were very dark gray to
black, and there was some degree of bleeding into the
substrate, indicating that at least some of the collected
material was liquid drops.
Literature Cited
(1) Nizich, S. V.; Misenheimer, D.; Pierce, T.; Pope, A.; Carlson, P.
National Air Pollutant Emission Trends, 1900-1995; EPA-454/
9
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R-96-007 (NTIS PB97-155329); U.S. Environmental Protection
Agency: October 1996; http:/ / www.epa.gov/ epahome/ publi-
cations.html.
(7) McCrillis, R. C.; Jaasma, D. R. Environ. Monit. Assess. 1993,
24:1, 1.
(8) Dasch, J. M. Environ. Sci. Technol. 1982, 16:10, 639.
(9) The values presented in ref 8 are based on data reported in the
following: Hall, R. E.; DeAngelis, D. G. J. Air Pollut. Control
Assoc. 1980, 30:8, 862.
(10) The values presented in ref 8 are based on data reported in the
following: Cooper, J. A. J. Air Pollut. Control Assoc. 1980, 30:8,
855.
(11) Locating and Estimating Air Emissions from Sources of Polycyclic
Organic Matter; EPA-454/ R-98-014 (NTIS PB98-159882); U.S.
Environmental Protection Agency: July 1998; http:/ / www/
epa.gov/ ttn/ chief.
(2) Rau, J. A.; Huntzicker, J. J. Size Distribution and Chemical
Composition of Residential Wood Smoke; Proceedings of the 78th
Annual Meeting of the AWMA; Detroit, MI, June 1985; Paper No.
85-43.3.
(3) McCrillis, R. C.; Kariher, P. Fireplace Emissions Update - New
Particle Size Data; Proceedings of the Emissions Inventory:
Planning for the Future; Research Triangle Park, NC, October
1997.
(4) Washington State RULE-MAKING ORDER CR-103; adopted
November 16, 1995, by the State Building Code Council,
Olympia, WA, http:/ / www.wa.gov.
(5) 40 CFR Part 60, Subpart AAA - Standards of Performance for
New Residential Wood Heaters, 7-1-97 ed.; Appendix A, Method
Received for review September 29, 1998. Revised manuscript
received February 3, 2000. Accepted February 3, 2000.
5G;
p 662. http:/ / www.access.gpo.gov/ nara/ cfr/ cfr-table-
search.html.
(6) Tugts, M.; Natschke, D. Emissions from Burning Cabinet Making
Scraps; EPA-600/ R-93-213 (NTIS PB94-130408); U.S. Environ-
mental Protection Agency; Appendix A, November 1993; p A-10.
ES981006F
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