EPA/600/A-92/136
92-110.
Analysis of Emissions from Residential Oil Furnaces
by
Robert C. McCrillis
Air and Energy Engineering Research Laboratory
and
Randall R. Watts
Health Effects Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711

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92-110.06
INTRODUCTION
In North America the four chief home heating fuels are, in
descending order of importance, natural gas, oil, electricity,
and wood. Each of these methods has its environmental drawbacks.
Electric heating devices, such as heat pumps, can be sources of
ozone-layer-depleting CFCs (chlorofluorocarbons), and the
otherwise clean-burning natural gas can add tons of carbon
dioxide to the atmospheric burden, thereby accelerating global
warming. This paper deals primarily with oil furnaces. Data are
presented on the total mass, extractable organics, filterable
particulate emissions, and mutagenicity of the organic fraction
from an oil furnace study run in a laboratory as part of the
Integrated Air Cancer Project's (IACP's) Roanoke study. This
discussion will point out the difference in emission rates for
oil furnaces when the newer retention head burners are used. The
filterable particulate data are compared to values in the
literature. The paper also presents preliminary results from the
oil furnaces studied in the Roanoke IACP field study.
DISCUSSION
The most frequently used home heating oil in North America
is No. 2 fuel oil. As reported previously1 No. 2 fuel oil may
be loosely defined as the cut in the distillation of crude oil
that lies between 375 and 625° F (190 and 330° C) (the higher the
number of the oil, the less volatile it is). It is a mixture of
four main groups of compounds: a homologous series of normal
alkanes; a related group of substituted alkanes; a homologous
series of alkyl benzenes; and, most importantly, a homologous
series of substituted naphthalenes. A number of olefins are also
present. When properly tuned, residential oil furnaces are
relatively clean burning, especially as compared to woodstoves.
Under typical tuned conditions, oil furnaces emit soot, unburned
fuel, and a range of hydrocarbons related to the fuel.
IACP Laboratory Study
Two types of residential oil furnace burners were used in
this study: a pre-1970 design atomizing-gun ABC Model 45 burner
and a modern design Thermo-Pride Model M-SR retention head
burner. The burners were installed and operated in a Williamson
Model 1167-15 residential oil furnace purchased in the late
1960s. For all tests, a 2.84 L/hr (0.75 gal./hr) fuel nozzle was
used with fuel at a pressure of 690 kPa (100 psi) on No. 2 fuel
oil. Results are shown in Table I.
The mutagenicity values shown in Table I were determined
using the microsuspension assay2 (MSA) using strain TA98 with
rat liver homogenate (+S9) activation. It is convenient to use
2

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92-110.06
the MSA assay as it requires much less sample than the standard
Ames plate incorporation assay. These preliminary results are
based on duplicate assays on the sample set. These analyses need
to be repeated on this and other sample sets to improve
confidence in the results. Samples from the same set also need
to be analyzed using the Ames plate incorporation assay to allow
comparison with Ames data in the literature.
Oil and Gas Furnace Data in Literature
The particulate data presented in the literature were
obtained primarily in the field, not the laboratory3'*. For the
oil furnace, 13 furnaces were tested representing a variety of
burner and furnace models. All used high pressure gun-type
burners, seven conventional head, five retention head, and one
shell head. The burner age ranges were 2 to 20 years and <1 to 5
years old for the conventional and retention head burners,
respectively. The shell head burner was 2 years old. Each was
tested as found and again after tuning. During the tests
reported here, the furnaces were operated on a 10 minute on, 20
minute off cycle. Average filterable particulate emissions (EPA
Method 5 front half) were 7.5 mg/MJ as found and 6.9 mg/MJ after
tuning. Average Bacharach smoke numbers were 1.3 and <1,
respectively. There was no significant difference in the average
emission factor and smoke number for the three types of burners
tested.
For the gas furnaces, filterable particulate values are 0.26
and 0.36 mg/MJ for sample periods one and two, respectively3.
Bacharach smoke number was not measured.
Comparison of Laboratory and Literature Oil Furnace Data
The oil furnace particle emissions and smoke number values
presented in the literature can be compared to the corresponding
values in Table I. First, a comparison of Bacharach smoke
numbers shows that the laboratory furnace was producing more
smoke. Even with the new technology burner under best tune
conditions, the smoke number was higher (2) than the "as found"
average field smoke number (1.3). Smoke number and particulate
emission rate would be expected to be directly related in a
general sense (i.e., if one increases, so does the other) for a
given burner. This may not be true when comparing burners since
start-up and shutdown can dominate particulate emission
generation while having no significant effect on full cycle smoke
readings.
^ Filterable Particulate. A direct comparison of particulate
emission factors is more complex. The only possible comparison
is between the laboratory filterable particulate data in Table I
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92-110.06
and the field filterable particulate oil furnace data in the
literature. The field data are based on EPA Method 5 front half.
Since the filter and probe were heated above 100 °C, most
unburned fuel would pass through the filter. The laboratory
study used a dilution sampler5' which extracts the sample from
the stack through a heated probe and then dilutes it with
filtered ambient air in an unheated dilution chamber before
passing the diluted mixture through an unheated filter. Thus the
Table I. Residential distillate oil combustion laboratory test
results1.
Burner
type*
Bach-
arach
smoke
No.
Furnace
condition
Filterable
particulate
mg/MJ1'
Extractable
organics,
mg/MJ
Filter XAD
c0/cEc
Mutagenicity
(MSA + S9),
rev/MJ"
O
8
poorly
tuned
6.80

7.20
1.02
-
0
8
poorly
tuned
5.56
1.13
5.43
0.83
29,800
N
3
typically
tuned
1.10
0.42
1.22
15.8
3, 900
N
2
best
tuned
1.66
1.03
1.79
24.2
7,900
0
4
best
tuned
8.36
2.92
3.79
1.08
16,800
(a)	0 = pre-1970 type, N - new, retention head type.
(b)	Fuel flowrate = 2.84 L/hr (0.75 gal./hr) for all tests
(fuel HHV = 53.2 MJ/L). Burner cycle = 10 minutes on,
20 minutes off.
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92-110.06
0.066, and 4.02 mg/MJ, respectively. This approach suggests that
the old technology burners in the laboratory and in the field
emitted about the same quantity of filterable particulate while
the new technology retention head burner in the laboratory
emitted about 2 orders of magnitude less than the retention head
burners tested in the field. By this approach, the gas furnaces
tested in the field emitted about one order of magnitude less
filterable particulates than the laboratory oil furnace with the
old burner and about 6 times more than with the new technology
retention head burner. This latter comparison makes this
approach suspect.
An alternative approach to comparing the field and
laboratory results is to assume that the Method 5 filter catch is
analogous to the nonextractable material on the dilution sampler
filter (filterable particulate minus filter extractable organics
in Table I). The Table I nonextractable averages for the
conventional and retention head burners are 4.94 and 0.66 mg/MJ,
respectively. By this second approach, the old technology
conventional burner in the laboratory produced about the same
emission factor as the conventional burners tested in the field
while the new technology retention head burner in the laboratory
emitted about an order of magnitude less filterable particulate
than the retention head burners tested in the field. By this
approach, the gas furnaces tested in the field emitted about one
order of magnitude less filterable particulates than the
laboratory oil furnace with the old burner and about half that
from the new technology retention head burner. This approach
seems to produce a more valid comparison although there is still
a major difference between the data for the retention head
burners.
The two approaches described above suggest that (1) a more
valid comparison can be made between the EPA Method 5 filterable
particulate and the nonextractable material on the dilution
sampler filter and (2) the conventional technology burners had
similar emission factors but the retention head burner operated
in the laboratory had a significantly lower emission factor than
the retention head burners tested in the field. One cannot say
whether these differences are due to the different sampling
methodologies, to real differences between the burners tested, or
to a combination of these factors. Preliminary results from the
IACP Roanoke study, presented later in this paper, address
further the question of representativeness.
Mutagenicity. The literature contains one reference to
mutagenicity of oil furnace emissions8 where emission particles
were collected in the laboratory by a Massive Air Volume Sampler,
and an Ames mutagenicity assessment showed 2500 revertants
5
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92-110.06
(rev)/MJ. In comparison, the MSA mutagenicity values presented
in Table I are the sum of the separate values from filter and XAD
extracts for each test except as noted. The percentage of the
mutagenicity due to the filter extracts ranged from only 37.3 to
50.8%, with an average of 46.1%. The mutagenicity of the filter
extracts ranged from 1,981 to 14,393 rev/MJ, which encompasses
the value in the literature. However, it should be noted that
the relationship between the standard Ames assay and the
microsuspension assay (MSA) employed in these experiments has not
been determined for this set of oil samples.
The mutagenicity of the emissions from the first test in
Table I can be estimated using the above average percentage of
the total mutagenicity found on the filters. The mutagenicity of
the XAD extract was 21,600 rev/MJ. Assuming the mutagenicity of
the filter extract would have represented 46.1% of the combined
filter and XAD extracts, the estimated total mutagenicity would
have been 40,000 rev/MJ.
Noting that the highest mutagenicities are associated with
the highest smoke number leads to the obvious conclusion that
poorly tuned furnaces are emitting not only more soot but also
greater quantities of mutagenic compounds and/or the compounds
emitted are more mutagenic. No mutagenicity data were found in
the literature for gas furnace emissions.
Comparison of Oil Furnace and Woodstove Mutagenicity Data
The IACP's first major emphasis was on residential wood
combustion, and the results have been widely published1,9.
Mutagenicity of woodstove source emissions has been shown to vary
over a wide range — from < 1 to > 10 rev/|ig total extractable
organics (filter plus XAD). On a per unit of heat value in the
wood, these data show that mutagenicity varies from 350,000 to
3,888,000 rev/MJ using the MSA. Comparing these values to the
MSA oil furnace data in Table I, it can be seen that woodburning
contributes 1-3 orders of magnitude more mutagenic potential to
the ambient air than burning oil in an oil furnace for the same
fuel heat input. The highest mutagenicity value for oil furnaces
is an order of magnitude less than the lowest mutagenicity value
for woodstoves. All of the woodsmoke mutagenicity results are
for emissions from conventional, uncontrolled units.
Preliminary IACP Roanoke Source Test Results
During the 1988-89 winter, IACP conducted an extensive field
study in Roanoke, VA, to study the mutagenic impact of
residential oil furnaces on ambient air. Secondarily, impacts of
motor vehicles and woodstoves were also investigated. The field
study included sampling emissions from the oil furnaces in 10
6
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92-110.06
residences. The study design called for each oil furnace house
to be paired with a gas or electric heated house. A summary of
the oil furnaces tested is presented in Table II. At least six
Table II. Summary of furnaces tested in Roanoke IACP field study.
House
code
Furnace description
Stack
gases,
%
Bacharach
smoke
number
Stack
draft,
in. H2o*
Efficiency,
%


C0a
o*



R01
Climate Control, burner model 72-
6, 30 yrs old, 1.27 MJ rating
6.3
12.5
3-4
0.04
76.2
R04
(no model data), 40 yrs old, 4,2
L/hr fuel nozzle
8,5
8,0
0
0,10
-
R07
Lennox model CC-358-363, burner
model LD1-75, 40 yrs old
8.3
9.8
1-2
0.03
79.2
RIO
Homart furnace and burner, >30
yrs old
7.5
10.3
10
0,05
71,0
R13
Mueller Climatrol model 227-110,
burner model 487-75, >30 yrs old,
9.3 MJ rating
9.0
8.8
2
0.03
74.0
R16
ftRCO Flame model Al-3, no burner
model No.,
7.5
11.0
5
0.045
70.5
R19
Kewanee model VT-510, Series 2X,
burner Petro model P-9-70-KA,
installed in 1951
8.3
9.6
2-3
0.04
79,5
R2Z
Heil, burner Wayne model M-SR,
1.1 MJ rating, new furnace
12.5
4.2
<1
0.03
81.5
R25
Airtemp, burner model 5813-1, 3.8
L/hr fuel nozzle, 20 yrs old
9.0
9.5
<1
0,03
72.2
R28
Mueller Climatrol, burner model
88-88, 2.5 L/hr fuel nozzle
6.5
12.6
1-2
0.05
67.0
(a) One inch of water pressure = 249 Pa
of the oil furnaces tested in Roanoke were more than 30 years old
while one was new. Smoke numbers covered the full range of the
scale <1-10); more than half had smoke numbers of 2 or below
while one was at the top of the scale.
Comparing Table II to the laboratory test results and the
data from the literature suggests that the laboratory furnace
probably had higher emissions than the field units, especially
with the old burner in the poorly tuned condition. The
laboratory furnace was much dirtier (on a smoke number basis)
than the literature furnaces. The Roanoke field study furnaces'
average smoke number was 2.8 compared to 1.3 for the furnaces
reported in the literature3 in the as found condition. One would
therefore expect higher emissions from the Roanoke furnaces
(these data are currently being reduced and will be reported at a
later date).
7
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92-110.06
SUMMARY AND CONCLUSIONS
Emissions data gathered on a residential oil furnace
operated with two types of burners in the laboratory have been
compared to field data and to uncontrolled woodstove emissions.
Preliminary oil furnace data gathered in the IACP field study in
Roanoke, VA, have been presented. Major conclusions from this
analysis follow:
•	Smoke number is a qualitative indicator of relative
particulate emissions from a given oil burner/furnace
combination. This may not be true when comparing across
burner/furnace combinations.
•	Mutagenicity of oil furnace emissions in revertants per
megajoule increases as particulate emissions increase.
•	Oil furnace emissions are 1-3 orders of magnitude less
mutagenic than wood smoke from conventional, uncontrolled
woodstoves on a per unit of fuel energy value (revertants
per mega joule).
REFERENCES
1.	Steiber, R.S. and R.C. McCrillis, "Comparison of Emissions
and Organic Fingerprints from Combustion of Oil and Wood,"
in Proceedings of the 84th AWMA Annual Meeting, Air & Waste
Management Association, Vancouver, British Columbia, Canada
1991, Paper No. 91-136.2.
2.	D.M DeMarini, M.M. Dallas and J. Lewtas, "Cytotoxicity and
Effect of Mutagenicity of Buffers in a Microsuspension
Assay," Teratogen., Carcinogen, and Mutagen. 9:287 (1989).
3.	Okuda, A.S. and L.P. Combs, Design Optimization and Field
Verification of an Integrated Residential Furnace - Phase 1
EPA-600/7-79-037a, (NTIS PB294-293), U.S. Environmental
Protection Agency, February 1979.
4.	Barrett, R.E., S.E. Miller and D.W. Locklin, Field
Investigation of Emissions from Combustion Equipment for
Space Heating, EPA-R2-73-084a (NTIS PB223-148) (also API
Publication 4180), U.S. Environmental Protection Agency,
June 1973.
5.	R.G. Merrill and D.B. Harris, "Field and Laboratory
Evaluation of a Woodstove Dilution Sampling System," in
Proceedings of the 80th AWMA Annual Meeting, Air & Waste
Management Association, New York, 1987, Paper No. 87-64.7.
8
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92-110.06
6.	Williamson, A.D. and D.B. Harris, "Measurement of
Condensable Vapor Contribution to PM10 Emissions," in
Proceedings of the 78th AWMA Annual Meeting, Air & Waste
Management Association, Detroit, 1985, Paper No. 85-14.4.
7.	Johnson, R.L., J.J. Shah, R.A. Cary and J.J. Huntzicker,
"An Automated Thermal-Optical Method for the Analysis of
Carbonaceous Aerosol," Atmospheric Aerosol Source/Air
Quality Relationships, 1981, Edited by E.S. Macias and P.K.
Hopke, A.C.S. Symposium Series 167, pages 223-233.
8.	J. Lewtas, "Genotoxicity of complex mixtures: strategies for
the identification and comparative assessment of airborne
mutagens and carcinogens from combustion sources,"
Fundamental and Applied Toxicology 10:571(1988).
9.	Lewtas, J., R.B. Zweidinger and L. Cupitt, "Mutagenicity,
Tumorigenicity and Estimation of Cancer Risk from Ambient
Aerosol and Source Emissions from Woodsmoke and Motor
Vehicles," in Proceedings of the 84th AWMA Annual Meeting,
Air & Waste Management Association, Vancouver, British
Columbia, Canada, 1991, Paper No. 91-131.6.
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-n onn TECHNICAL REPORT DATA
J\ Hi Xi>xt Lj~ 1 oUU a (Please read Instructions on the reverse before compiet
1. REPORT NO.
EPA/600/A-92/136
2.
3.
4. TITLE AND SUBTITLE
Analysis of Emissions from Residential Oil
5. REPORT DATE
Furnaces


6. PERFORMING ORGANIZATION CODE
7, AUTHOR(S)
R. C. McCrillis (EPA/AEERL) and R. R. Watts
(EPA /HER L)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS

10. PROGRAM ELEMENT NO.
See Block 12


11. CONTRACT/GRANT NO.
NA (Inhouse)
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development

13. TYPE OF REPORT AND PERIOD COVERED
Published paper; 3/88-3/89
Air and Energy Engineering Research Laboratory
Research Triangle Park, North Carolina 27711
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES
541-2733. Presented at 85t
project officer is Robert C. McCrillis, Mail Drop 61. 919/
n AWMA annual meeting, Kansas City, MO, 6/21-26/92
16. abstract paper gives results of a series of emission tests on a residential oil
furnace to determine emissions from two types of burners. A number of analyses
were performed on the emissions, including total mass, filterable particulate, total
extractable organics, and mutagenicity. Preliminary results are also presented on
oil furnaces tested by the EPA in Roanoke, VA, during the 1988-89 winter under the
Integrated Air Cancer Project field study. These data are compared to data in the
literature.
17.
KEY WORDS AND DOCUMENT ANALYSIS

a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution Residential Buildings
Furnaces Mass
Burners Particles
Fuel Oil Organic Compounds
Emission Mutagens
Analyzing
Pollution Control
Stationary Sources
Particulate
13 B 13 M
13A 14 G
21D 07C
14G 06 E
14B
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