ASTM D2157-18

Standard Test Method for Effect of Air Supply on Smoke Density in Flue Gases from Burning Distillate Fuels

SIGNIFICANCE AND USE
5.1 This test method relates efficiency of operation of domestic heating equipment to clean burning. Reducing combustion air in a burner gives more efficient operation. The extent to which combustion air can be reduced is limited by the onset of unacceptable smoke production. By delineating the relation between smoke density and air supply, this test method (together with net stack temperature data) defines the maximum efficiency for a given installation at any acceptable smoke level.  
5.2 For certain types of equipment, such as the rotary wall-flame burner, too much excess air will cause smoke as well as too little. For these cases, the point of minimum excess air at the acceptable smoke level indicates the optimum efficiency.  
5.3 The operating temperatures of the equipment will affect these test results. The relation of excess air to smoke density is thus susceptible to some change at different points in an operating cycle. In practice, an adequate compromise is possible by operating the burner for 15 min before any readings are recorded and then obtaining the test data within a succeeding 25 min period.  
5.4 Under laboratory conditions, CO2 readings are reproducible to ±0.3 % and smoke readings are reproducible to ±1/2 smoke spot number.
SCOPE
1.1 This test method covers the evaluation of the performance of distillate fuels from the standpoint of clean, efficient burning. It is intended primarily for use with home heating equipment burning No. 1 or No. 2 fuel oils. It can be used either in the laboratory or in the field to compare fuels using a given heating unit or to compare the performance of heating units using a given fuel.
Note 1: This test method applies only to pressure atomizing and rotary-type burners.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.2.1 Arbitrary and relative units are also used.  
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-Mar-2018
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.E0 - Burner, Diesel and Non-Aviation Gas Turbine Fuels

Relations

• Replaces: ASTM D2157-94(2013) - Standard Test Method for Effect of Air Supply on Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 01-Apr-2018
• Refers: ASTM D2156-09(2024) - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 01-Mar-2024
• Refers: ASTM D2156-09(2018) - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 01-Oct-2018
• Refers: ASTM D2156-09(2013) - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 01-Oct-2013
• Refers: ASTM D2156-09 - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 01-Dec-2009
• Refers: ASTM D2156-08 - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 01-Dec-2008
• Refers: ASTM D2156-94(2003) - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 01-Nov-2003
• Refers: ASTM D2156-94(1999) - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
• Effective Date: 10-Apr-1999

Overview

ASTM D2157-18: Standard Test Method for Effect of Air Supply on Smoke Density in Flue Gases from Burning Distillate Fuels is a critical test method used to evaluate how variations in combustion air supply influence smoke density in flue gases produced by burning distillate fuels, particularly No. 1 and No. 2 fuel oils. Primarily applicable to home heating equipment with pressure atomizing and rotary-type burners, this method helps determine the efficiency and cleanliness of burner operations. The standard can be utilized both in laboratory and field settings to compare fuel performance in specific heating units or to assess the performance of different heating systems using the same fuel.

Key Topics

• Smoke Density Measurement: Utilizes a specified procedure to measure smoke density (expressed as a Smoke Spot Number) in flue gases emitted by domestic burners.
• Combustion Air Adjustment: Establishes the relationship between the amount of combustion air supplied and smoke production, identifying the optimal air-to-fuel ratio for maximum efficiency without excessive smoke.
• Efficiency and Clean Burning: Links operational efficiency with smoke levels, guiding adjustments to burners for optimal performance.
• Applicability: Intended for domestic heating equipment-specifically pressure atomizing and rotary burners burning distillate fuels (No. 1 and No. 2 fuel oils).
• Data Reproducibility: Under laboratory conditions, this method demonstrates reproducibility with CO₂ readings within ±0.3% and smoke readings within ±0.5 smoke spot number.

Applications

This ASTM standard is widely applied in the heating oil and equipment manufacturing industries to:

• Optimize Burner Operation: Identify the most efficient and clean settings for domestic oil burners by correlating combustion air supply with smoke density.
• Fuel and Equipment Comparison: Enable meaningful laboratory and field comparisons between different burner units or fuels under consistent test conditions.
• Regulatory and Environmental Compliance: Support efforts to reduce environmental impact by minimizing smoke emissions, thus aiding compliance with air quality standards.
• Quality Control in Manufacturing: Aid boiler and burner manufacturers in developing products that meet efficiency and emissions requirements.
• Maintenance and Servicing: Offer a framework for field technicians and service companies to diagnose and fine-tune burners for better fuel economy and reduced emissions in residential heating systems.

Related Standards

• ASTM D2156 - Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels: This referenced method details the procedures for measuring smoke spot number, directly supporting the implementation of ASTM D2157.
• ASTM Committee D02 - The subcommittee focuses on burner, diesel, non-aviation gas turbine, and marine fuels, overseeing the development and maintenance of ASTM D2157 and related standards.

Practical Value

By specifying a standard method for assessing the effect of air supply on smoke density, ASTM D2157-18 provides valuable guidance for:

• Improving operational efficiency of domestic heating equipment
• Reducing maintenance frequency, as clean combustion lessens soot buildup
• Enhancing fuel economy and reducing heating costs for consumers
• Lowering emissions for improved indoor and outdoor air quality

For engineers, technicians, and manufacturers seeking to reduce heating oil smoke emissions while maximizing efficiency, adherence to ASTM D2157-18 is an essential step toward cleaner and more economical operation of residential oil-fired heating equipment.

Keywords: ASTM D2157, smoke density, flue gases, heating oil, distillate fuels, combustion air supply, No. 1 fuel oil, No. 2 fuel oil, burner efficiency, domestic heating equipment, emissions testing, oil burner standards, fuel comparison, clean burning.

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: D2157 − 18
Standard Test Method for
Effect of Air Supply on Smoke Density in Flue Gases from
Burning Distillate Fuels
This standard is issued under the fixed designation D2157; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 3. Terminology
3.1 Definitions of Terms Specific to This Standard:
1.1 This test method covers the evaluation of the perfor-
mance of distillate fuels from the standpoint of clean, efficient
3.1.1 effıciency, n—the percentage of gross heat of combus-
burning. It is intended primarily for use with home heating tion of the fuel which is retained by the equipment and which
equipment burning No. 1 or No. 2 fuel oils. It can be used
does not pass out in the flue gases.
either in the laboratory or in the field to compare fuels using a
3.1.2 excess combustion air, n—the percentage of air enter-
given heating unit or to compare the performance of heating
ing the equipment over and above that needed for stoichiomet-
units using a given fuel.
ric conversion of the fuel to the ultimate combustion products,
essentially CO and water, for a normal fuel.
NOTE 1—This test method applies only to pressure atomizing and
rotary-type burners.
3.1.2.1 Discussion—This may be calculated from the per-
1.2 The values stated in SI units are to be regarded as
centage CO in the flue gas and the carbon-hydrogen ratio of
standard. The values given in parentheses after SI units are
the fuel.
provided for information only and are not considered standard.
3.1.3 flue-gas carbon dioxide (CO ), n—the percentage
1.2.1 Arbitrary and relative units are also used.
concentration of carbon dioxide in the flue gas, measured by
1.3 This standard does not purport to address all of the
conventional Orsat analysis, or the equivalent.
safety concerns, if any, associated with its use. It is the
3.1.4 net stack temperature, n—the difference between the
responsibility of the user of this standard to establish appro-
stack temperature and the ambient temperature of the air near
priate safety, health, and environmental practices and deter-
the inlet to the burner.
mine the applicability of regulatory limitations prior to use.
3.1.5 smoke density, n—the concentration of smoke in the
1.4 This international standard was developed in accor-
flue gas, measured as a Smoke Spot Number as described in
dance with internationally recognized principles on standard-
Test Method D2156.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4. Summary of Test Method
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4.1 The flue-gas smoke density is measured for various
amounts of combustion air while the burner is operating at
2. Referenced Documents
equilibrium conditions. Results are expressed as a plot of
smoke density as a function of flue-gas carbon dioxide (CO )
2.1 ASTM Standards:
content, or alternatively, as a function of percentage excess
D2156 Test Method for Smoke Density in Flue Gases from
combustion air.
Burning Distillate Fuels
5. Significance and Use
1 5.1 This test method relates efficiency of operation of
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
domestic heating equipment to clean burning. Reducing com-
Subcommittee D02.E0 on Burner, Diesel, Non-Aviation Gas Turbine, and Marine
bustion air in a burner gives more efficient operation. The
Fuels.
extent to which combustion air can be reduced is limited by the
Current edition approved April 1, 2018. Published April 2018. Originally
onset of unacceptable smoke production. By delineating the
approved in 1963. Last previous edition approved in 2013 as D2157 – 94 (2013).
DOI: 10.1520/D2157-18.
relation between smoke density and air supply, this test method
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(together with net stack temperature data) defines the maxi-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
mumefficiencyforagiveninstallationatanyacceptablesmoke
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. level.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2157 − 18
5.2 For certain types of equipment, such as the rotary
wall-flame burner, too much excess air will cause smoke as
well as too little. For these cases, the point of minimum excess
air at the acceptable smoke level indicates the optimum
efficiency.
5.3 The operating temperatures of the equipment will affect
these test results. The relation of excess air to smoke density is
thus susceptible to some change at different points in an
operating cycle. In practice, an adequate compromise is pos-
sible by operating the burner for 15 min before any readings
are recorded and then obtaining the test data within a succeed-
FIG. 1 Typical Smoke-CO and Excess Air-CO Curves
2 2
ing 25 min period.
5.4 Under laboratory conditions, CO readings are repro-
composition data and flue gas CO by conventional methods.
ducible to 60.3 % and smoke readings are repr
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2157 − 94 (Reapproved 2013) D2157 − 18
Standard Test Method for
Effect of Air Supply on Smoke Density in Flue Gases from
Burning Distillate Fuels
This standard is issued under the fixed designation D2157; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This test method covers the evaluation of the performance of distillate fuels from the standpoint of clean, efficient burning.
It is intended primarily for use with home heating equipment burning No. 1 or No. 2 fuel oils. It can be used either in the laboratory
or in the field to compare fuels using a given heating unit or to compare the performance of heating units using a given fuel.
NOTE 1—This test method applies only to pressure atomizing and rotary-type burners.
1.2 The values stated in inch-poundSI units are to be regarded as standard. The values given in parentheses are mathematical
conversions to after SI units that are provided for information only and are not considered standard.
1.2.1 Arbitrary and relative units are also used.
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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2.1 ASTM Standards:
D2156 Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 effıciency—effıciency, n—defined as the percentage of gross heat of combustion of the fuel which is retained by the
equipment and which does not pass out in the flue gases.
3.1.2 excess combustion air—air, n—the percentage of air entering the equipment over and above that needed for stoichiometric
conversion of the fuel to the ultimate combustion products, essentially CO and water, for a normal fuel. This may be calculated
from the percentage CO in the flue gas and the carbon-hydrogen ratio of the fuel.
3.1.2.1 Discussion—
This may be calculated from the percentage CO in the flue gas and the carbon-hydrogen ratio of the fuel.
3.1.3 flue-gas carbon dioxide (CO )—), n—the percentage concentration of carbon dioxide in the flue gas, measured by
conventional Orsat analysis, or the equivalent.
3.1.4 net stack temperature—temperature, n—the difference between the stack temperature and the ambient temperature of the
air near the inlet to the burner.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.E0 on Burner, Diesel, Non-Aviation Gas Turbine, and Marine Fuels.
Current edition approved May 1, 2013April 1, 2018. Published August 2013April 2018. Originally approved in 1963. Last previous edition approved in 20082013 as
D2157 – 94 (2008).(2013). DOI: 10.1520/D2157-94R13.10.1520/D2157-18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2157 − 18
3.1.5 smoke density—density, n—the concentration of smoke in the flue gas, measured as a Smoke Spot Number as described
in Test Method D2156.
4. Summary of Test Method
4.1 The flue-gas smoke density is measured for various amounts of combustion air while the burner is operating at equilibrium
conditions. Results are expressed as a plot of smoke density as a function of flue-gas carbon dioxide (CO ) content, or alternatively,
as a function of percentage excess combustion air.
5. Significance and Use
5.1 This test method relates efficiency of operation of domestic heating equipment to clean burning. Reducing combustion air
in a burner gives more efficient operation. The extent to which combustion air can be reduced is limited by the onset of
unacceptable smoke production. By delineating the relation between smoke density and air supply, this test method (together with
net stack temperature data) defines the maximum efficiency for a given installation at any acceptable smoke level.
5.2 For certain types of equipment, such as the rotary wall-flame burner, too much excess air will cause smoke as well as too
little. For these cases, the point of minimum excess air at the acceptable smoke level indicates the optimum efficiency.
5.3 The operating temperatures of the equipment will affect these test results. The relation of excess air to smoke density is thus
susceptible to some change at different points in an operating cycle. In practice, an adequate compromise is possible by operating
the burner for 15 min before any readings are recorded and then obtaining the test data within a succeeding 25-min25 min period.
5.4 Under laboratory conditions, CO rea
...