ASTM E2558-13(2021)

Standard Test Method for Determining Particulate Matter Emissions from Fires in Wood-Burning Fireplaces

SIGNIFICANCE AND USE
5.1 This test method is used for determining emission factors and emission rates for low mass wood-burning fireplaces.  
5.1.1 The emission factor is useful for determining emission performance during product development.  
5.1.2 The emission factor is useful for the air quality regulatory community for determining compliance with emission performance limits.  
5.1.3 The emission rate may be useful for the air quality regulatory community for determining impacts on air quality from fireplaces, but must be used with caution as use patterns must be factored into any prediction of atmospheric particulate matter impacts from fireplaces based on results from this method.  
5.2 The reporting units are grams of particulate per kilogram of dry fuel and grams of particulate per hour.  
5.2.1 Appropriate reporting units for comparing emissions from non-heating appliances: grams per kilogram.  
5.2.2 Appropriate reporting units for predicting atmospheric emission impacts only if hours of fireplace use are factored in: grams per hour.
SCOPE
1.1 This test method covers the fueling and operating protocol for determining particulate matter emissions from wood fires in low mass wood-burning fireplaces. The fueling and operating protocol for determining particular matter emissions from masonry or other high mass fireplaces is covered in Annex A1 of this test method.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jan-2021
• ICS: 13.040.40 - Stationary source emissions
• ICS: 97.100.30 - Solid fuel heaters
• Technical Committee: E06 - Performance of Buildings
• Drafting Committee: E06.54 - Solid Fuel Burning Appliances

Relations

• Refers: ASTM E2515-11(2017) - Standard Test Method for Determination of Particulate Matter Emissions Collected by a Dilution Tunnel
• Effective Date: 01-Sep-2017
• Refers: ASTM E631-15 - Standard Terminology of Building Constructions
• Effective Date: 01-Mar-2015
• Refers: ASTM E631-14 - Standard Terminology of Building Constructions
• Effective Date: 01-Nov-2014
• Refers: ASTM E2515-11 - Standard Test Method for Determination of Particulate Matter Emissions Collected by a Dilution Tunnel
• Effective Date: 01-Nov-2011
• Refers: ASTM E2515-10 - Standard Test Method for Determination of Particulate Matter Emissions Collected by a Dilution tunnel
• Effective Date: 01-Sep-2010
• Refers: ASTM E2515-09 - Standard Test Method for Determination of Particulate Matter Emissions Collected by a Dilution tunnel
• Effective Date: 01-May-2009
• Refers: ASTM E2515-07 - Standard Test Method for Determination of Particulate Matter Emissions Collected by a Dilution tunnel
• Effective Date: 01-May-2007
• Refers: ASTM E631-06 - Standard Terminology of Building Constructions
• Effective Date: 01-Jun-2006
• Refers: ASTM E631-93a(1998)e1 - Standard Terminology of Building Constructions
• Effective Date: 28-Jul-2000

Overview

ASTM E2558-13(2021) is a standardized test method developed by ASTM International for determining particulate matter (PM) emissions from fires in wood-burning fireplaces, specifically low mass types. This method provides a consistent protocol for testing and quantifying emissions, aiding manufacturers in product development and supporting air quality regulatory compliance. It establishes fueling and operational procedures, measurement criteria, and reporting units pertinent to PM emissions from residential wood combustion appliances.

Key Topics

• Particulate Matter Emissions: The standard outlines procedures to determine both emission factors (grams of particulate per kilogram of dry fuel) and emission rates (grams of particulate per hour) from wood-burning fireplaces.
• Testing Protocol: Detailed steps for preparing, fueling, igniting, and operating low mass fireplaces are specified to ensure accurate, repeatable emission measurements.
• Reporting Units: Results are primarily reported in grams per kilogram (g/kg) of dry fuel and grams per hour (g/hr), which aids in both comparative appliance assessment and atmospheric impact analysis.
• Applicable Fireplace Types: Core methods address low mass wood-burning fireplaces; an annex covers masonry or other high mass fireplaces.
• Safety and Calibration: The standard emphasizes the user’s responsibility to adhere to safety, health, and environmental practices, and specifies calibration requirements for measurement equipment.
• International Compliance: Developed in line with internationally recognized principles, ASTM E2558 aligns with WTO standards and technical barriers to trade recommendations.

Applications

ASTM E2558-13(2021) delivers practical value across several sectors:

• Product Development: Manufacturers utilize emission factor data during the R&D phase to optimize fireplace combustion efficiency and particulate emission control.
• Regulatory Compliance: Air quality authorities and environmental regulators use emission limits defined by this test method to assess compliance of wood-burning fireplaces with local or national particulate matter standards.
• Public Health and Air Quality Assessment: The emission rates measured can help policymakers predict potential air quality impacts, provided real-world usage patterns are factored into such calculations.
• Comparative Appliance Testing: By establishing a standardized test protocol, the method enables fair comparison between products, fostering innovation and performance improvements in low mass wood-burning fireplace designs.

Related Standards

Several other standards and references are closely associated with ASTM E2558-13(2021):

• ASTM E2515: Used in conjunction with E2558 for the determination of particulate matter emissions collected via dilution tunnel methods.
• ASTM E631: Provides building construction terminology and definitions relevant to this test method.
• NIST Monograph 175: Offers temperature reference data for calibration of thermocouples and temperature sensors required by the standard.

Conclusion

ASTM E2558-13(2021) is an essential standard for consistent evaluation of particulate emissions from low mass wood-burning fireplaces. It supports manufacturers, regulators, and the air quality community with rigorous, science-based protocols for measuring, reporting, and comparing emission performance. Proper application of this test method contributes to better product design, regulatory compliance verification, and advancement of public health through improved air quality management.

Keywords: ASTM E2558-13, particulate matter emissions, wood-burning fireplace test, fireplace emission standard, air quality compliance, fireplace emission factor, particulate matter measurement, low mass fireplace, fireplace operation protocol, emission standard, ASTM fireplace testing.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2558 − 13 (Reapproved 2021)
Standard Test Method for
Determining Particulate Matter Emissions from Fires in
Wood-Burning Fireplaces
This standard is issued under the fixed designation E2558; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Thermocouple Types Based on the ITS-90
1.1 This test method covers the fueling and operating
3. Terminology
protocol for determining particulate matter emissions from
wood fires in low mass wood-burning fireplaces. The fueling
3.1 Definitions—Terms used in this test method are defined
and operating protocol for determining particular matter emis-
in Terminology E631.
sions from masonry or other high mass fireplaces is covered in
3.2 Definitions of Terms Specific to This Standard:
Annex A1 of this test method.
3.2.1 base of fireplace, n—the lowest part of the fireplace
1.2 The values stated in inch-pound units are to be regarded
assembly that would normally be in contact with the floor of
as standard. The values given in parentheses are mathematical
the dwelling or structure in which it is installed.
conversions to SI units that are provided for information only
3.2.2 Douglas fir, n—untreated, standard, or better grade
and are not considered standard.
Douglasfirlumberwithagencygradestamp:D.FirorDouglas
1.3 This standard does not purport to address all of the
Fir.
safety concerns, if any, associated with its use. It is the
3.2.3 firebox, n—the volume within the fireplace where logs
responsibility of the user of this standard to establish appro-
are burned.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3.2.4 first fuel crib, n—the first fuel load (including fuel
1.4 This international standard was developed in accor-
pieces and spacers to create air spaces) placed on the residual
dance with internationally recognized principles on standard-
fuel from the kindling brands. The specific configuration is
ization established in the Decision on Principles for the
described in 9.3.5.1.
Development of International Standards, Guides and Recom-
3.2.5 fuel piece, n—2×4or4×4 wood pieces used to
mendations issued by the World Trade Organization Technical
construct fuel cribs and referring to the nominal width and
Barriers to Trade (TBT) Committee.
depthdimensionsforcommonlyavailabledimensionallumber.
1 1
The actual dimensions are 1 ⁄2 in. ×3 ⁄2 in. (38mm × 89mm)
2. Referenced Documents
1 1
and 3 ⁄2in.×3 ⁄2 in. (89mm×89mm).
2.1 ASTM Standards:
3.2.6 grate, n—any device included with the fireplace or
E631Terminology of Building Constructions
specified by the fireplace manufacturer for the purpose of
E2515Test Method for Determination of Particulate Matter
elevatingthefuelloadabovethehearthorforconstrainingfuel
Emissions Collected by a Dilution Tunnel
pieces from falling outside the intended burning area, or both.
2.2 NIST Document:
This includes basket grates and andirons.
Monograph 175Temperature-Electromotive Force Refer-
ence Functions and Tables for the Letter-Designated
3.2.7 hearth, n—the footprint of the fireplace firebox.
3.2.8 kindling brands, n—the initial fuel load or loads
This test method is under the jurisdiction of ASTM Committee E06 on
placedabovecrumplednewspapertoinitiatecombustioninthe
Performance of Buildings and is the direct responsibility of Subcommittee E06.54
fireplace and to establish a charcoal bed that will become the
on Solid Fuel Burning Appliances.
ignition source for subsequent fuel loads.These are comprised
Current edition approved Feb. 1, 2021. Published February 2021. Originally
approved in 2007. Last previous edition approved in 2013 as E2558–13. DOI:
offuelstripsseparatedbyairspaces.Thespecificconfiguration
10.1520/E2558-13R21.
is described in 9.3.4.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3.2.9 low mass fireplace, n—any fireplace and attached
Standards volume information, refer to the standard’s Document Summary page on
chimney that can be weighed (including the weight of the test
the ASTM website.
3 fuel) on a platform scale that meets the requirements as
Available from National Institute of Standards and Technology (NIST), 100
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. specified in 7.3 and 8.2.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2558 − 13 (2021)
3.2.10 nominal fuel length, n—the Nominal Fuel Length the home.An algorithm that uses the specific configuration of
(NFL) is one of five incremental nominal fuel piece lengths the test fireplace, including hearth and grate dimensions, is
that simulates real-world firewood five piece lengths. These used to determine the kindling and fuel crib geometry and
lengthsare16in.(406mm),18in.(457mm),20in.(508mm), dimensions. Kindling brands are placed in the fireplace above
22 in. (559mm), and 24 in. (610mm). The NFL is used for
crumpled newspaper and ignited. When the kindling brands
both the kindling brands and fuel cribs. haveburnedtoacertainpoint,thefirstfuelcribisplacedonthe
remains of the kindling. When the first crib is substantially
3.2.11 particulate matter (PM), n—all gas-borne matter
burned, the remaining material is adjusted as needed to form a
resultingfromcombustionofsolidfuel,asspecifiedinthistest
base for the second crib. This process is repeated again before
method, which is collected in accordance with Test Method
additionofthethirdcrib.Thethirdcribisallowedtoburnuntil
E2515.
all flaming from volatile material in the fuel ceases, at which
3.2.12 second fuel crib, n—the second fuel load (including
point the test is terminated. Burn rate is determined based on
fuel pieces and spacers to create air spaces) placed on the
the amount of fuel added less the amount remaining at the end
residual fuel from the first fuel crib.The specific configuration
of the test divided by the length of test and corrected to a dry
is described in 9.3.5.2.
fuelbasis.Particulatesamplingbeginsatthetimeofignitionof
3.2.13 spacers, n—wood pieces used to hold individual fuel
the newspaper and stops when the test terminates. The total
pieces together when constructing the three fuel cribs. Their
particulate emissions are determined over the test period. The
function is to provide reproducible fuel crib geometry and air
particulate emissions factor is then determined from the total
spaces between fuel pieces, as well as to hold the fuel cribs
emissions and the total amount of fuel burned and is reported
together (with nails).
in grams of particulate per dry kilogram of fuel or grams of
3.2.14 standardized fuel retainer, n—any fireplace that particulate per hour.
doesn’t include or specify a grate as defined in 3.2.6 shall use
4.2 Ifthetestfireplaceincludesstandard(oroffersoptional)
astandardizedfuelretainerduringtesting.Theseretainersshall
components that affect particulate emission performance and
include vertical fuel retainer bars that are made from
that have more than one operating position or condition
0.75in.×0.75 in. (19mm×19mm) steel square bar or 0.75
allowed in the owner’s manual that accompanies the fireplace,
in. (19mm) diameter round steel bar and shall be 8in. 62 in.
separateemissionstestsmayberequiredforeachofthevarious
(200mm 650mm) high. They shall be attached to a steel
positions or conditions that are allowed in the manual. This
platethatprojectstowardthefrontofthefireplaceandshallnot
might include things like door open and door closed operation,
interfere with any fireplace function. They shall be spaced so
for example. (See 9.4.14 – 9.4.16.)
they are 12in. 6 ⁄2in. (300mm 613mm) apart. Their pur-
pose is to prevent fuel from rolling or falling forward during
5. Significance and Use
testing, thus helping to prevent an aborted test. (See Fig. 1.)
5.1 This test method is used for determining emission
3.2.15 test facility, n—the area in which the tested fireplace
factors and emission rates for low mass wood-burning fire-
is installed, operated, and sampled for emissions.
places.
3.2.16 third fuel crib, n—the third and final fuel load
5.1.1 Theemissionfactorisusefulfordeterminingemission
(including fuel pieces and spacers to create air spaces) placed
performance during product development.
on the residual fuel from the second fuel crib. The specific
5.1.2 The emission factor is useful for the air quality
configuration is described in 9.3.5.3.
regulatory community for determining compliance with emis-
4. Summary of Test Method
sion performance limits.
4.1 This test method is used in conjunction with Test 5.1.3 The emission rate may be useful for the air quality
Method E2515. The fireplace under evaluation is fueled with regulatory community for determining impacts on air quality
kindlingandcribsinawaythatsimulatesfireplaceoperationin from fireplaces, but must be used with caution as use patterns
FIG. 1 Example, Standardized Fuel Retainer
E2558 − 13 (2021)
mustbefactoredintoanypredictionofatmosphericparticulate expected test fuel charge weight, whichever is greater, recali-
matter impacts from fireplaces based on results from this brate the scale before use with at least five calibration weights
method. spanning the operational range of the scale.
5.2 The reporting units are grams of particulate per kilo- 8.3 Test Fuel Scale—Perform a multipoint calibration (at
gram of dry fuel and grams of particulate per hour. leastfivepointsspanningtheoperationalrange)ofthetestfuel
5.2.1 Appropriate reporting units for comparing emissions scalebeforeitsinitialuse.Thescalemanufacturer’scalibration
from non-heating appliances: grams per kilogram. results are sufficient for this purpose. Before each certification
5.2.2 Appropriatereportingunitsforpredictingatmospheric test, audit the scale with the wood heater in place by weighing
emission impacts only if hours of fireplace use are factored in: at least one calibration weight (ASTM Class F) that corre-
grams per hour. sponds to between 20% and 80% of the expected test fuel
charge weight. If the scale cannot reproduce the value of the
6. Safety
calibration weight within 0.01 lb (0.005 kg) or1%ofthe
expected test fuel charge weight, whichever is greater, recali-
6.1 Disclaimer—This test method may involve hazardous
brate the scale before use with at least five calibration weights
materials,operations,andequipment.Thistestmethodmaynot
spanning the operational range of the scale.
address all of the safety concerns associated with its use. It is
the responsibility of the user of this test method to establish
8.4 Temperature Sensors—Temperature measuring equip-
appropriate safety and health practices and to determine the
ment shall be calibrated before initial use and at least semi-
applicability of regulatory limitations prior to performing this
annually thereafter. Calibrations shall be in compliance with
test method.
National Institute of Standards and Technology (NIST) Mono-
graph 175 Temperature-Electromotive Force Reference Func-
7. Equipment and Supplies
tions and Tables for the Letter-Designated Thermocouple
Types Based on the ITS-90.
7.1 Wood Moisture Meter—Calibrated electrical resistance
meter capable of measuring test fuel moisture to within 1 %
9. Procedure
moisture content. Must meet the calibration requirements
specified in 8.1.
9.1 Preconditioning of the Fireplace—Prior to testing for
emissions, the fireplace to be evaluated must be burned until
7.2 Test Fuel Scale—Ascalecapableofweighingtestfuelto
within 0.01 lb (0.005 kg). Must meet the calibration require- the weight of the fireplace is stable to within 60.5lb
(60.25kg) but for no less than 10h for fireplaces without
ments specified in 8.3.
catalytic combustors or no less than 48 h for fireplaces with
7.3 Platform Scale—A scale capable of weighing the test
catalytic combustor(s). This may be done inside or outside the
fireplaceandattachedchimney,includingtheweightofthetest
test facility.
fuel, to within 0.1 lb (0.05 kg). Must meet the calibration
9.1.1 Set up the fireplace in accordance with instructions
requirements specified in 8.2.
provided by the manufacturer. The total height of chimney
7.4 Fireplace Flue Gas Temperature Measurement
when measured from the base of the fireplace shall be 15ft 6
Device—A0.125 in. (3.2 mm) diameter sheathed, non-isolated
1ft (4.6m 6 0.3m).
junction Type K thermocouple capable of measuring flue gas
9.1.2 Install a flue-gas temperature measurement device at
temperature with an accuracy of 4.0°F (2.2°C) or 0.75 % of
the center of the flue, 8ft 6 0.3ft (2.4m 6 0.1m) above the
the reading, whichever is greater and meeting the calibration
base of the fireplace.
requirements specified in 8.4.
9.1.3 Record the start time, fireplace weight, and flue gas
temperature.
7.5 Fireplace Temperature Measuring Device—A tempera-
9.1.4 Ignite a fire using newspaper and kindling and estab-
ture sensor capable of measuring firebox surface temperatures
with an accuracy of 4.0°F (2.2°C) or 0.75 % of the reading, lishanactivelyburningfire.Addmorefuelasneededtosustain
the fire.
whichever is greater and meeting the calibration requirements
specified in 8.4.
NOTE 1—Any type of untreated wood may be used for the precondi-
tioning.
8. Calibration and Standardization
9.1.5 Record the time and weight for all fuel added.
8.1 Wood Moisture Meter—Calibrate as in accordance with
9.1.6 Record the flue-gas temperature at least once during
the manufacturer’s instructions before each certification test.
each 30 min of operation.
8.2 Platform Scale—Perform a multipoint calibration (at 9.1.7 Periodically allow the fire to burn down completely.
While the fireplace is still warm, shovel out all residual fuel,
leastfivepointsspanningtheoperationalrange)oftheplatform
scalebeforeitsinitialuse.Thescalemanufacturer’scalibration ash and other debris, lift the fireplace off the scale, re-zero the
scaleandreturnthefireplacetoscale.Recordtheemptyweight
results are sufficient for this purpose. Before each certification
test, audit the scale with the test fireplace in place by weighing of the fireplace. Repeat this process of burning the fireplace
and determining the empty weight until the weight becomes
at least one calibration weight (ASTM Class F) that corre-
sponds to between 20% and 80% of the expected test fuel stable in accordance to the requirements of 9.1.
charge weight. If the scale cannot reproduce the value of the 9.1.8 When the fireplace weight has stabilized or after at
calibration weight within 0.1 lb (0.05 kg) or 1% of the least 10 h of preconditioning fires for fireplaces without
E2558 − 13 (2021)
catalyticcombustorsoratleast48hofpreconditioningfiresfor Average all the readings for all the fuel strips for both kindling
fireplaces with catalytic combustor(s), whichever is longer, brandscombinedtodeterminetheaveragefuelmoistureforall
recordtheendingtime,totalwoodweightofwoodburned,and kindling.
total elapsed time of operation. (2) Main Fuel Cribs—The average fuel moisture for each
9.1.9 Allow the fireplace to cool to room temperature and
fuelpieceusedtoconstructeachofthethreefuelcribsshallbe
remove all unburned wood, charcoal, ash, or other debris from between 19 and 25% dry basis. Kiln-dried lumber is not
the firebox.
permitted. Kiln-dried lumber is permitted for the spacers.
9.1.10 Clean the chimney using a standard chimney brush Determine the fuel moisture for each fuel piece (excluding
appropriately sized for the chimney.
spacers) used for each of the three fuel cribs by averaging at
leastthreefuelmoisturemeterreadings,onefromeachofthree
9.2 Install the fireplace in the test facility.
sides, measured parallel to the wood grain. If an electrical
9.2.1 Set up the fireplace in accordance with instructions
resistance type fuel moisture meter is used, penetration of
provided by the manufacturer. Use the chimney type supplied
insulated electrodes shall be ⁄4 the thickness of the fuel piece
or specified by the manufacturer. The total height of chimney
or ⁄4 in. (19mm), whichever is greater.
when measured from the base of the fireplace shall be 15ft 6
9.3.1.3 Fuel Density—The average fuel density, dry basis,
1ft (4.6m 6 0.3m). Do not install a chimney cap.
3 3 3
shall be in the range of 27lb⁄ft to 34 lb/ft (0.434g⁄cm to
NOTE 2—The chimney that is used for testing should be documented in
0.546 g/cm ) for the two kindling brands combined and for
the test data and test report.
each of the three individual fuel cribs. Nails and spacer pieces
9.2.2 Center the flue outlet (chimney) under the dilution
are excluded from the density determinations. Determine the
tunnel hood. Refer to Test Method E2515 for specific require-
total volume of the fuel pieces that comprise both kindling
ments including positioning the flue outlet to meet induced
brands combined and each individual fuel crib. Use the wet
draft and smoke capture requirements.
basisweightandthearithmeticallyaverageddrybasismoisture
9.2.3 Install a flue-gas temperature measurement device at
content (refer to 9.3.1.2 (1) and 9.3.1.2 (2)) to determine the
the center of the flue, 8ft 6 0.3ft (2.4m 6 0.1m) above the
drybasisweightforthekindlingandfortheindividualfuelcrib
base of the fireplace.
pieces. Determine dry basis weight for each fuel crib by
9.3 Fuel:
summingthedrybasisweightoftheindividualfuelpiecesthat
9.3.1 Fuel Properties:
comprise each crib. Divide the dry basis weight by the volume
9.3.1.1 The fuel is untreated, standard, or better grade
to determine the density for the combined kindling brands and
Douglas fir lumber.
for each fuel crib.
9.3.1.2 Fuel Moisture—Thefuelmoistureshallbemeasured
9.3.1.4 Nails—Use uncoated, ungalvanized nails for assem-
using a fuel moisture meter as specified in 7.1. Moisture shall
blingkindlingbrandsandmainfuelloads.Thenumberofnails
not be added to previously dried fuel pieces except by storage
used should be limited to the minimum number necessary to
under high humidity conditions and temperature up to 100°F
hold the kindling brands and fuel cribs together.
(38°C). Fuel moisture shall be measured within four hours of
9.3.1.5 Weight—Record the total weight of each kindling
using the fuel for a test.
brand or main fuel crib after it is assembled using the test fuel
(1) Kindling Loads—The average fuel moisture for each
scale specified in 7.2. The weighed fuel brands and cribs must
fuelstripusedineachofthetwospecifiedkindlingbrandsshall
be used within3hof being weighed.
be between 6% and 12% dry basis. Kiln-dried lumber is
9.3.2 Nominal Fuel Length—The NFL for each fireplace
permitted for the kindling brands. Determine fuel moisture for
being evaluated is determined based on dimensional param-
each fuel strip. One moisture meter reading from each strip,
eters of the fireplace firebox or grate, or both.
measuredparalleltothewoodgrainissufficient.Ifanelectrical
resistance type fuel moisture meter is used, penetration of 9.3.2.1 If the fireplace includes a manufacturer supplied or
insulated electrodes shall be ⁄4 the thickness of the fuel strips. specified grate (see Fig. 2 (A) and (B)), the NFL is:
FIG. 2 (A) and (B) NFL Example, Plan Views, Traditional with Grate
E2558 − 13 (2021)
(1)Thelongestofthefivestandardfuellengthsthatwillfit (3)If the manufacturer’s written instructions that accom-
in or on the grate without interference from any part of the pany the fireplace include a specific fuel piece length recom-
grate structure, or; mendationforthefireplaceuser,therecommendedlengthshall
(2)If the grate does not include end log retainer bars that be used.
limit fuel length, the longest of the five standard fuel lengths
NOTE 4—If the manufacturer’s recommended length is not one of the
that does not extend by more than 2 in. past either end of the
fivestandardfuellengths,usethecloseststandardfuellengththatdoesnot
longest horizontal grate dimension when the fuel length is
exceed the manufacturer’s recommended length.
centered left-to-right on the grate, or;
(4)Standardized fuel retainers shall be used for any fire-
(3)If the 2in. extension of the fuel past the longest grate
place that does not have a grate.
dimensioncausesinterferencewiththewallsofthefirebox,the
9.3.2.3 Dimensional tolerance for the NFL is ⁄16 in.
longest of the standard fuel lengths that can be centered on the
(61.5mm).
grate without interference from the firebox walls, or;
9.3.2.4 If the fireplace firebox has height restrictions that
(4)If the manufacturer’s written instructions that accom-
will cause interference when loading test fuel cribs, the NFLis
pany the fireplace include a specific fuel piece length recom-
longest NFL that provides a minimum of 6 in. of vertical
mendationforthefireplaceuser,therecommendedlengthshall
clearance to the top of the firebox from the hearth or loading
be used.
areaforthefuel(orfromthegrateorthetopofthelogretainers
NOTE 3—If the manufacturer’s recommended length is not one of the
on the grate if a grate is provided or specified) over the full
fivestandardfuellengths,usethecloseststandardfuellengththatdoesnot
length of the NFL when the NFL is centered on the hearth or
exceed the manufacturer’s recommended length.
grate. See Fig. 4.
9.3.2.2 If the fireplace has no grate supplied or specified by
9.3.3 Newspaper:
the manufacturer, the NFL is determined as follows:
(1)If the manufacturer’s written instructions that accom- 9.3.3.1 Loosely crumpled balls of full sheets of non-color
ink newspaper are used to ignite the kindling loads. The
pany the fireplace provide no specific information regarding
wherefuelmayormaynotbeplacedinthefirebox,thelongest number of balls is dependent on the NFL. The intent is to
ensure rapid and even ignition of the kindling brands. The
fuellengththatwillfitwithoutinterferencefromthesidewalls
of the firebox, while still allowing the front edge of the first following guideline (Table 1) is given:
TABLE 1 Guideline for Newspaper Used for Igniting Kindling
kindling crib to be no closer to the front of the fireplace
openingthan ⁄3thedepthofthefireplaceor6in.,whicheveris
NFL Newspaper
in. mm # of Sheets
less. (See Fig. 3 (A) and (B)), or
16 406 4
(2)If the manufacturer’s written instructions that accom-
18 457 5
pany the fireplace provide specific information regarding 20 508 6
22 559 7
where fuel may or may not be placed in the firebox, the NFL
24 610 8
is the longest fuel length that will fit without interference from
thesidewallsofthefirebox,whilestillallowingthefrontedge 9.3.4 Kindling Loads—There are two kindling brands that
of the first kindling crib to be within the area of the firebox
are used to establish an initial charcoal bed and to ignite the
where fuel is allowed to be placed per the manufacturer’s firstfuelcrib.ThekindlingbrandsarecomprisedofDouglasfir
written instructions. (See Fig. 3 (B)), or, pieces that meet the specifications of 9.3.1.
FIG. 3 (A) and (B) NFL Example, Plan Views, Fireplaces without Grates
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(2)For fireplaces that do not include a grate or do not
specify a grate that must be used, the kindling brands and fuel
loads are burned directly on the fireplace hearth and the first
3 3
kindling brand is comprised of two layers of ⁄4 in. × ⁄4 in.
(19mm×19mm)stripsconstructedinaccordancewith9.3.4.1
(1) but with the addition of two spacer pieces that attached to
the underside of the bottom layer of the brand.The spacers are
1 1
comprised of 1 ⁄2 in. × 1 ⁄2 in. (38mm × 38mm) pieces. The
spacers are 8 ⁄4 in. (210mm) long and positioned at each end
ofthebrandandparalleltothepiecesthatcomprisethebottom
layer of the brand. (See Fig. 6 and Fig. 8.)
9.3.4.2 Second Kindling Brand—Thesecondkindlingbrand
is comprised of two layers. The fuel pieces are nailed together
using18gaugeorsmallernailsnolongerthan1 ⁄8in.(35mm).
The two layers are perpendicular to each other. (See Fig. 9.)
1 1
(1)The bottom layer is comprised of 1 ⁄2 in. × 1 ⁄2 in.
FIG. 4 NFL Example, Front View, Fireplace with
1 1
Firebox Height Interference
(38mm × 38mm) pieces or a combination of 1 ⁄2in. × 1 ⁄2 in.
3 1
(38mm×38mm)and ⁄4in.×1 ⁄2in.(19mm×38mm)pieces
3 1
spaced 1 ⁄8 in. (35 mm) apart. Each piece is 8 ⁄4 in. (210mm)
long. The number and position of each strip is determined by
9.3.4.1 First Kindling Brand:
the NFL. (See Fig. 9 and Fig. 10 and Table 3.)
(1)Forfireplacesthatincludeagrateorspecifythatagrate
3 3
(2)The top layer is comprised of four ⁄4in. × ⁄4 in.
must be used, the first kindling brand is comprised of two
3 3
(19mm × 19mm) strips. The outer strips are located at the
layers of ⁄4in. × ⁄4in. (19mm × 19mm). The strips are
ends of the lower layer pieces and the remaining two strips are
spaced ⁄2in. (12.7mm) apart and nailed together using 18
spaced 1 ⁄2 in. (38mm) from the first two. The TLL is
gaugeorsmallernailsnolongerthan1 ⁄8in.(35mm).Thetwo
determined by the NFL. (See Fig. 9, Fig. 10, and Table 3.)
layers are perpendicular to each other. (See Fig. 5 and Fig. 7.)
(a)Thebottomlayeriscomprisedofstripsthatare8 ⁄4in. 9.3.5 Main Fuel Loads—Therearethreemainfuelcribsthat
(210mm) long.The number of strips is dependent on the NFL are added to the fire as described in 9.4. The cribs are
as determined in Table 3. (See Table 2.) comprised of dimensional lumber assembled in specific pat-
(b)The top layer is comprised of seven strips. The top terns with specific air spaces between the pieces. The dimen-
layer length (TLL) is determined by the NFL. (See Table 2.) sional lumber pieces are air-dried Douglas fir that meet the
FIG. 5 Kindling Brand 1 (With Grate)
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FIG. 6 Kindling Brand 1 (No Grate)
FIG. 7 Kindling Brand 1 (With Grate)
FIG. 8 Kindling Brand 1 (No Grate)
specifications of 9.3.1. The fuel spacer pieces are Douglas fir of2×4 dimensional lumber plus six spacers. The length of
that meet the specifications of 9.3.1. All pieces are nailed each fuel piece is the NFL as determined in 9.3.2.The2×4
together. Fuel spacer pieces are attached to the dimensional fuel pieces face the front of the fireplace and are offset from
lumber pieces using 18 gauge or smaller nails no longer than each other by ⁄8in. (3mm). The crib is assembled using four
3 3 1 1 1
1 ⁄8 in. (35mm). ⁄4in.×1 ⁄2 in. (19mm × 38mm) spacers and two ⁄2in.×1 ⁄2
9.3.5.1 First Fuel Crib—The first fuel crib is comprised of in. (12.7mm × 38mm) spacers. (See Fig. 11 for the specific
onefuelpieceof4×4dimensionallumberandtwofuelpieces details of construction.)
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TABLE 2 Kindling Brand 1
(1)Locate the first kindling brand on the grate or on the
NFL Lower Layer Top Layer Length hearth in accordance with the manufacturer’s written instruc-
in. mm # of Strips in. mm
tions that are supplied with the fireplace, or if no written
16 406 13 15 ⁄4 400
instructions are provided, see below.
18 457 15 18 ⁄4 464
20 508 17 20 ⁄4 527 (2)If the fireplace has a grate, center the first kindling
22 559 18 22 559
brand on the grate, both front-to-back and left-to-right.
24 610 20 24 ⁄2 622
(3)If the fireplace does not have a grate, place the first
kindling brand so that it is centered left-to-right and is as far
back in the fireplace as possible. Without compressing the
TABLE 3 Kindling Brand 2
newspaper balls anymore than absolutely needed, nestle the
NFL Lower Lower Top Layer Length
first kindling brand so that it is as level as possible on the
Layer Layer
in. mm #of2×2 #of1×2 in. mm
newspaper balls.
16 406 6 0 15 ⁄8 403
9.4.3.3 Record the weight of and then place the second
18 457 6 1 18 457
kindling brand on top of the first. The short fuel pieces should
20 508 6 2 20 ⁄8 511
22 559 8 0 21 ⁄8 549
be on the bottom, closest to the first kindling brand. Center the
24 610 8 0 24 ⁄2 591
second kindling brand over the first, both front-to-back and
left-to-right.
9.4.4 For fireplaces without grates, place the standardized
9.3.5.2 Second Fuel Crib—The second fuel crib is com-
fuel retainer so that the back surfaces of the vertical fuel
prised of two fuel pieces of4×4 dimensional lumber and one
retainer bars are within ⁄2 in. (13mm) of the front of the
fuel piece of 2 × 4 dimensional lumber plus two spacers. The
deepest of the three main fuel cribs (typically, this will be the
lengthofeachfuelpieceistheNFLasdeterminedin9.3.2.The
second fuel crib). Center the standardized fuel retainer from
2 × 4 fuel piece and one4×4 fuel piece are nailed together
left to right.
with three 8-penny common nails to form a nominal4×6
1 9.4.5 When all requirements for starting the emissions test
piece. The nails are centered on the width of the 3 ⁄2in.
aremetinaccordancewithTestMethodE2515,recordthestart
(89mm) face of the 2 × 4, with one nail at the center of the
time, record the indicated scale weight of the fireplace includ-
NFLandtheothertwospacedin4in.(100mm)fromeachend.
3 1 ing the combined weight of newspaper and first and second
The crib is assembled using two ⁄4in.×1 ⁄2 in. (19mm ×
kindling brands or, if the scale has been tared, record the
38mm) spacers so that the fuel pieces are rotated 45° from
combined weight of the newspaper and first and second
horizontal. The4×4 faces the front of the fireplace. (See Fig.
kindling brands directly, start the sampling equipment, and
12 for the specific details of construction.)
then ignite the newspaper balls.Apropane gas torch has been
9.3.5.3 Third Fuel Crib—Thethirdfuelcribiscomprisedof
foundtobeagooddeviceforobtainingrapidandevenignition
two fuel pieces of2×4 dimensional lumber plus spacers. The
of the newspaper. Quickly work your way from one side to the
lengthofeachfuelpieceistheNFLasdeterminedin9.3.2.The
1 1 other to insure even ignition. All newspaper must be ignited
cribisassembledusingsix ⁄2in.×1 ⁄2in.(12.7mm×38mm)
within 30 s from starting the sampling equipment.
spacers. (See Fig. 13 for the specific details of construction.)
9.4.6 When the indicated scale weight is between 20% and
9.4 Operation:
15% of the combined weight (wet) of the newspaper, first and
9.4.1 Prior to beginning a test, measure the temperature of
second kindling brands, record the time and add the first fuel
the fireplace. Use a surface temperature probe held against the
cribinaccordancewiththefollowingprocedure.(SeeFig.15.)
center of the back wall of the firebox until a constant
temperature is obtained. The fireplace temperature must be NOTE 5—When determining the indicated scale weight range that fuel
loads should be added or for determining when fuel adjustments are
withintheallowabletestfacilitytemperaturerangespecifiedin
allowed in accordance with 9.4, round the calculated weight range values
Test Method E2515.
to the nearest 0.1lb (0.05kg) that is still within the calculated weight
9.4.2 Within 10 min prior to starting the emissions test run,
range. For example, if the kindling and newspaper weigh 5.8lb (2.65kg),
record the indicated scale weight of the empty fireplace/
the 15% to 20% calculated allowable weight range for adding the first
chimney assembly. If the test will be conducted using a fuelcribinaccordancewith9.4.6wouldequal0.87lb(0.40kg)to1.16lb
(0.53kg)
...