ASTM E2816-20a

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: E2816 − 20 E2816 − 20a An American National Standard
Standard Test Methods for
Fire Resistive Metallic HVAC Duct Systems
This standard is issued under the fixed designation E2816; 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.
INTRODUCTION
Heating, Ventilation, Air Conditioning (HVAC) duct systems may be subjected to fire- exposure
conditions. ISO 6944 is a standard test method used to evaluate ventilation ducts. However, ISO 6944
does not address all of the fire resistive attributes deemed necessary by some authorities having
jurisdiction, for example, (1) the transition from the horizontal to a vertical HVAC duct, (2) the
attachment of the HVAC duct’s supports to the fire-separating elements, (3) the termination of an
HVAC duct system and the protection of its ends, (4) the effects of rapid cooling and erosion upon the
HVAC duct system, (5) the use of fire dampers and (6) the effect of the HVAC duct system on its
supporting construction. Many types of fire-resistive materials are used to protect HVAC ducts. These
fire-resistive materials are either applied to HVAC ducts in the field or are fabricated as an integral part
of the HVAC duct system when shipped from the factory. Evaluating fire-resistive materials used to
protect a HVAC duct from fire is an aid for predicting their fire performance and helps to establish
uniformity in requirements of various authorities. To do this it is necessary that the fire-resistance
properties of HVAC ducts protected with fire-resistive materials be measured and specified according
to a common standard expressed in terms that are applicable alike to a wide variety of materials,
situations, and conditions of exposure.
1. Scope*
NOTE 1—Use of the standard designation ISO 6944 refers to both ISO 6944:1985 and ISO 6944-1:2008.
1.1 These test methods evaluate the fire-resistive metallic HVAC duct system’s fire resistance and fire-engulfment with
horizontal and vertical through-penetration firestops.
NOTE 2—The intent of these test methods is to provide authorities having jurisdiction a means to evaluate the fire performance of HVAC duct systems
to enable their application and use.
1.2 These test methods evaluate the fire performance of HVAC ducts, including both supply (pressurized: Condition A –
Horizontal and Condition B – Vertical) and return (exhaust: Condition C – Horizontal and Condition D – Vertical).
1.3 These test methods evaluate the ability of a HVAC duct system to resist the spread of fire from one compartment to other
compartments separated by a fire resistance rated construction when the HVAC duct system is exposed to fire under one or more
of the following conditions:
1.3.1 Condition A—Fire exposure from the outside of the horizontal HVAC duct system without openings,
1.3.2 Condition B—Fire exposure from the outside of the vertical HVAC duct system without openings,
1.3.3 Condition C—Fire exposure from the outside with hot gases entering the inside of the horizontal HVAC duct system with
unprotected openings,
NOTE 3—Unprotected openings are openings that are not protected by fire dampers.
1.3.4 Condition D—Fire exposure from the outside with hot gases entering the inside of the vertical HVAC duct system with
unprotected openings.
1.4 These test methods provide a means for determining the fire-resistance of vertical and horizontal HVAC duct systems, when
subjected to the standard time-temperature curve of Test Methods E119.
These test methods are under the jurisdiction of ASTM Committee E05 on Fire Standards and are the direct responsibility of Subcommittee E05.11 on Fire Resistance.
Current edition approved March 15, 2020April 15, 2020. Published April 2020May 2020. Originally approved in 2011. Last previous edition approved in 20182020 as
E2816 -18b.-20. DOI: 10.1520/E2816-20.10.1520/E2816-20A.
*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
E2816 − 20a
1.4.1 Condition A—These test methods provide a means for evaluating a horizontal HVAC duct system, without openings
exposed to fire, passing through a vertical fire-separating element.
1.4.2 Condition B—These test methods provide a means for evaluating a vertical HVAC duct system, without openings exposed
to fire and outfitted with a horizontal connection, passing through a horizontal fire-separating element.
1.4.3 Condition C—These test methods provide a means for evaluating a horizontal HVAC duct system, with unprotected
openings exposed to fire, passing through a vertical fire-separating element.
1.4.4 Condition D—These test methods provide a means for evaluating a vertical HVAC duct system with a horizontal
connection, and with unprotected openings exposed to fire, passing through a horizontal fire-separating element.
1.5 These test methods prescribe a standardized fire exposure for comparing the test results of the fire resistive materials and
HVAC duct systems. The results of these tests are one factor in assessing predicted fire performance of HVAC duct systems. Using
these test results to predict the performance of actual HVAC duct systems requires the evaluation of test conditions.
1.6 The values stated in inch-pound units are to be regarded as the standard. The SI values given in parentheses are for
information only, unless the SI units are used consistently to perform all of the test methods referenced herein. In this case, the
SI units will be regarded as the standard and will be used in Section 13, Report.
1.7 The text of these test methods references notes and footnotes which provide explanatory material and (excluding those in
tables and figures) shall not be considered as requirements of the fire-test-response standard.
1.8 This document specifically excludes evaluating ducts that carry combustibles, flammable vapors, combustible gases, and
commercial kitchen ventilation systems commonly called grease ducts or hazardous exhaust ducts, which are tested in compliance
with Test Methods E2336.
1.9 This standard is used to measure and describe the response of materials, products, or assemblies to heat and flame under
controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials,
products, or assemblies under actual fire conditions.
1.10 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.
1.11 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these
tests.
1.12 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:
E119 Test Methods for Fire Tests of Building Construction and Materials
E176 Terminology of Fire Standards
E631 Terminology of Building Constructions
E814 Test Method for Fire Tests of Penetration Firestop Systems
E2226 Practice for Application of Hose Stream
E2307 Test Method for Determining Fire Resistance of Perimeter Fire Barriers Using Intermediate-Scale, Multi-story Test
Apparatus
E2336 Test Methods for Fire Resistive Grease Duct Enclosure Systems
2.2 Other Standards:
UL 385 Standard for Play Pipes for Water Supply Testing in Fire-Protection Service
ISO 6944:1985 Fire Resistance Tests – Ventilation Ducts
ISO 6944-1:2008 Fire Containment – Elements of Building Construction – Part 1: Ventilation ducts
SMACNA HVAC Duct Construction Standards
DW/144 Specification for Sheet Metal Ductwork
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from Underwriters Laboratories (UL), 2600 N.W. Lake Rd., Camas, WA 98607-8542, http://www.ul.com.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
Available from Sheet Metal and Air Conditioning Contractors’ National Association, 4201 Lafayette Center Drive Chantilly, Virginia 20151-1219, www.smacna.org.
Available from BESA, Building Engineering Services Association, www.besapublications.com.
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3. Terminology
3.1 For definitions of terms used in these test methods and associated with fire issues, refer to the definitions contained in
Terminology E176.
3.2 For definitions of terms used in these test methods and associated with building issues, refer to the definitions contained in
Terminology E631.
3.3 When there is a conflict between Terminology E176 and Terminology E631 definitions, Terminology E176 definitions shall
apply.
3.4 Definitions of Terms Specific to This Standard:
3.4.1 fire resistive material, n—the product applied to or a part of the HVAC duct to provide fire resistance.
3.4.2 fire-separating element, n—floors, walls, and partitions having a period of fire resistance determined in accordance with
fire resistance test methods such as Test Methods E119.
3.4.3 fire side, adj—the surface of the test assembly or test specimen exposed to the heat or flame, or both, of the test apparatus.
3.4.4 integrity, n—the absence of cracks, holes or openings that appear outside the furnace on the fire-resistive material or
firestop, or both, or through which flames or hot gases pass as determined by the cotton pad test.
3.4.5 orifice, n—the continuous hollow area or opening within the HVAC duct.
3.4.6 stability, n—the ability of the HVAC duct, support and fastening system to fulfill their intended function.
3.4.7 supporting construction, n—the arrangement of building sections forming the fire-separating elements into which the
HVAC duct system is installed.
3.4.8 support system, n—the vertical or horizontal devices used to sustain the HVAC duct and its fire-resistive materials and
their fastening means.
3.4.9 test assembly, n—the complete construction composed of a test specimen(s) together with its supporting construction.
3.4.10 test specimen, n—a material, product, or assemblage of a specific design, composition, density, and dimension, for
example, a HVAC duct protected with a fire-resistive material(s) that is secured by fastening system, which is suspended by a
support system, and protected by a firestop(s).
3.4.10.1 Discussion—
The fire-resistive material or the HVAC duct system are examples of test specimens.
3.4.11 unexposed side, n—the surface not directly exposed to the heat or flame, or both, of the test apparatus.
3.4.12 unexposed surface thermocouple, n—temperature-measuring device placed on the unexposed surface.
3.4.13 HVAC duct, n—a tube or conduit utilized for conveying air without combustible materials, flammable vapors, and
combustible gases.
3.4.14 HVAC duct system, n—consists of the HVAC duct, a fire-resistive material(s), a support system, the through-penetration
firestop(s) and fastening system(s).
4. Summary of Test Method
4.1 Representative test specimens of the fire-resistive material or the HVAC duct system are subjected to the selected tests for
the purposes of assisting the authority having jurisdiction in qualifying an HVAC duct system to a an explicit set of their
requirements. These test methods describe the following test sequence and procedures:
4.1.1 A fire-engulfment test uses a standardized fire exposure to simulate a fire occurring on the outside of the HVAC duct
system in Conditions A and B, or a fire occurring on the inside and outside of the HVAC duct system in Conditions C and D, and
demonstrates the ability of the HVAC duct system to remain intact without a through opening appearing in supporting construction
or the HVAC duct system outside the furnace or raising the temperature on its unexposed surface above the limitations of these
test methods or conveying hot gases into other compartments. The fire-engulfment test also tests the fastening methods used to
secure the fire-resistive material to the HVAC duct and the support system. The fire-engulfment test also provides a means to test
a through-penetration firestop to determine its compatibility with the HVAC duct when mounted in a horizontal or vertical
fire-separating element. A hose stream test is also performed on the test assembly in accordance with the provisions in Practice
E2226.
5. Significance and Use
5.1 These test methods are intended to evaluate the ability of the HVAC duct system and its supporting construction to do the
following:
5.1.1 Resist the effects of a standardized fire exposure, and
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5.1.2 Retain its integrity.
5.2 These test methods provide for the following measurements and evaluations where applicable:
5.2.1 Ability of the tested support system to carry the load of the HVAC duct and its fire-resistive material(s) during the entire
duration of the standardized fire-engulfment test.
5.2.2 Ability of the firestops to meet the requirements of Test Method E814 when used as part of a HVAC duct system.
5.2.3 Ability of the HVAC duct system to resist the passage of flames and hot gases onto its unexposed surface during a
standardized fire-resistance test.
5.2.4 Transmission of heat through the HVAC duct system during a standardized fire-resistance test.
5.2.5 Ability of the firestop to resist the passage of water during a standardized hose stream test.
5.3 These test methods do not provide the following:
5.3.1 Full information as to performance of the fire-resistive material, supporting construction, or the HVAC duct system
constructed with components, densities, or dimensions other than those tested.
5.3.2 Evaluation of the degree by which the fire-resistive material or HVAC duct system contributes to the fire hazard by
generation of toxic gases, or other products of combustion.
5.3.3 Measurement of the degree of control or limitation of the passage of smoke or products of combustion through the HVAC
duct system.
5.4 The test specimens are subjected to one or more specific tests under laboratory conditions. When different test conditions
are substituted or the end-use conditions are changed, it is not always possible by, or from, these test methods to predict changes
to the characteristics measured. Therefore, the results of these laboratory tests are valid only for the exposure conditions described
in these test methods.
5.5 These test methods require a test specimen to be exposed to a standard fire that is controlled to achieve specified
temperatures throughout a specified time period. The engulfment test is followed by the application of a standardized hose stream
test. These test methods provide a relative measure of the fire-test-response of comparable fire-resistive materials and HVAC duct
systems under these exposure conditions. The fire exposure is not representative of all fire conditions because conditions vary with
changes in the amount, nature and distribution of fire loading, ventilation, compartment size and configuration, and heat sink
characteristics of the compartment. Variation from the test conditions or test specimen construction, such as size, materials, method
of assembly, also affects the fire-test-response. For these reasons, evaluation of the variation is required for application to
construction in the field.
NOTE 4—When the size of the HVAC duct exceeds the capability of the test furnace to test it, the authority having jurisdiction (AHJ) should be
consulted to determine what test and evaluation of the variation is required for application to construction in the field.
6. Apparatus
6.1 Furnace—An enclosure capable of containing a fire being controlled to the time-temperature curve as required by the test
method being conducted, for example, Test Methods E119, and meeting the dimensional requirements to contain the test assembly.
6.2 Furnace Thermocouples:
6.2.1 The furnace thermocouples shall comply with the time constant, dimensional and physical requirements of those specified
in the fire resistance test method being conducted: Test Methods E119 and E814.
NOTE 5—A typical furnace thermocouple assembly meeting the time constant requirements of Test Methods E119 and E814 is fabricated by
fusion-welding the twisted ends of No. 18 gage Chromel-Alumel wires, mounting the leads in porcelain insulators and inserting the assembly so the
thermocouple bead is approximately 0.5 in. (12.7 mm) from the sealed end of the standard weight nominal 0.5-in. (12.7-mm) iron, steel, or Inconel pipe.
The time constant for this and for several other thermocouple assemblies was measured in 1976. Another option is to calculate the time constant from
knowledge of its physical and thermal properties.
6.3 Pressure-sensing Probes:
6.3.1 The pressure-sensing probes shall meet the requirements specified in the fire resistance test method being conducted: Test
Methods E119 and E814.
6.4 Unexposed Surface Thermocouples:
6.4.1 The unexposed surface thermocouples, which shall be covered by the thermocouple pads described in 6.5 during testing,
shall meet the requirements specified in the fire resistance Test Method E2307.
6.5 Thermocouple Pads:
6.5.1 The thermocouple pads used to cover each thermocouple on the unexposed side of the test specimen or test assembly shall
be made of materials that meet the requirements specified in the fire resistance Test Method E2307.
6.6 Differential Pressure Measurement Instruments:
6.6.1 The differential pressure measurement instrument shall be:
Inconel is a registered trade name of INCO Alloys, Inc., 3800 Riverside Dr., Huntingdon, WV 25720.
Supporting data is available from ASTM International Headquarters. Request RR:E05-1001.
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6.6.2 A manometer or equivalent transducer meeting the requirements specified in the fire resistance test method being
conducted: Test Methods E119 and E814.
6.6.3 Capable of reading in graduated increments of no greater than 0.01 in. H O (2.5 Pa) with a precision of not less than
60.005 in. H O (61.25 Pa).
6.7 Hose Stream Delivery System:
6.7.1 The hose stream delivery system shall consist of the same apparatus used in Practice E2226.
6.7.2 Maintain the hose stream on the test assembly for the duration of application in accordance with Practice E2226.
6.8 Air Flow Systems:
6.8.1 For Conditions A and B, a fan or similar apparatus capable of producing a negative pressure of 1.20 6 0.06 in. H O (300
6 15 Pa) within HVAC duct as compared to the fire-exposure environment during the fire-engulfment test. The fan is connected,
either directly or by a suitable length of flexible ducting, to the measuring device.
6.8.2 For Conditions C and D, a fan or similar apparatus capable of producing an air velocity when extracting gas from the
HVAC duct of at least 3 m/s (10 ft/s) measured at ambient temperature in the HVAC duct before the fire-engulfment test. The fan
is connected, either directly or by a suitable length of flexible ducting, to the measuring device. Maintain the air velocity at 3 6
0.45 m/s (9.8 6 1.5 ft/s) during the test, except for the 5-min period each 30 min. During this 5-min period, the fan either (1)
remains on but the air flow is not drawn through the HVAC duct, or (2) the fan is shut off at the beginning of the 5-min period
and restarted after the 5-min period. The integrity of the HVAC duct is determined during this 5-min period. The 5-min period
begins at 25 min and is repeated every 30 min.
7. Sampling, Test Specimens, and Test Assemblies
7.1 Sampling:
7.1.1 Document the origin of the materials being tested.
7.1.1.1 Document the materials’ lot number, batch number, product name, packaging and other relevant information on the
packaging, for example, third-party marks, test method references, etc.
7.1.1.2 Document whether samples were submitted by test sponsor.
7.1.1.3 Document whether samples were randomly selected from test sponsor’s inventory by an independent third-party. Include
the date of the sampling, the sample method, the location of the sampling, the person performing the sampling.
7.1.1.4 Document whether production of the samples was witnessed and their quality, manufacturing procedures, and
composition were documented by an independent third-party. Include the date of the sampling, the sample method, the location
of the sampling, the person performing the sampling.
NOTE 6—Some evaluation services require an approved inspection agency or certification body to witness the fire-resistive material production to
establish traceability to the test specimens and that the fire-resistive material be representative of the product as applied in the field.
7.2 Fire-Engulfment Test Specimen:
7.2.1 The test specimen shall be representative of the construction for which Interpretation of Results is desired, as to materials,
workmanship, and details, such as dimensions of parts, joints, and expansion joints, and shall be built under conditions
representative of those in building construction and operation. The test specimen sections passing through the fire separating
element shall be symmetrical. Alternatively, when asymmetrical test specimen sections pass through the fire separating element,
testing from each side of the fire separating element shall be performed unless it is documented that the side with the lower fire
resistance rating is being tested. The physical properties of the materials and ingredients used in the test specimen shall be
determined and documented.
7.2.1.1 Construct the HVAC duct using the maximum dimensions and minimum metal thickness (gage) for which approval is
sought. Document the HVAC duct material, dimensions, thickness of material, the type of any internal and external reinforcement,
and the connection (joint) type.
NOTE 7—A successful test on the HVAC duct in 7.2.1.1 normally qualifies the fire-resistive material for use on rectangular ducts with equal or less
widths and equal or less cross-sectional areas, and round ducts with equal or less cross-sectional areas.
7.2.1.2 Document the support system used to carry the load of the HVAC duct and its fire-resistive materials and their fastening
means, for example, metal angle size and length, hole size and location on metal angle, threaded rod diameter and length, location
and spacing relationship (distance) between HVAC duct and threaded rods, location and spacing between support systems,
anchoring means and installation method used to secure the support system, etc.
7.2.2 The test specimen shall be constructed or assembled, or both, in accordance with the manufacturer’s instructions. All
construction methods shall be documented.
7.2.3 All sections of the HVAC duct shall have joints. The type of joint tested shall be documented. When a specific type of
joint or support is designated by industry nomenclature, for example, SMACNA, that particular nomenclature shall be used to
describe the joint or support. The HVAC duct system conditions (A and B) shall have a branch connection.
NOTE 8—SMACNA HVAC Duct Construction Standards and DW/144, Specification for Sheet Metal Ductwork are two examples of industry
publications that provide guidance for HVAC duct design.
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7.2.4 The opening area shall be 50 6 5 % of the cross sectional area of the HVAC duct made from one or more openings. The
interior area of the branch, ’T’ or elbow, shall be 25 6 5 % of the interior area of the HVAC duct.
7.2.5 Testing qualifies the performance of HVAC ducts, either supply (pressurization: Condition A – Horizontal and Condition
B – Vertical) or return (exhaust: Condition C – Horizontal and Condition D – Vertical) or both (test all Conditions). The HVAC
duct shall be one or more of the following:
7.2.5.1 Condition A—Fire from the outside of the horizontal HVAC duct system without openings, shall consist of the following
minimum components assembled to meet the layout and the dimensional requirements in Fig. 1 that has at least: one joint on the
fire side, one joint located on the unexposed side, one straight section, one “T” section, and one 90-degree elbow with an end cap.
7.2.5.2 Condition B—Fire from the outside of the vertical HVAC duct system without openings, shall consist of the following
minimum components assembled to meet the layout and the dimensional requirements in Fig. 2 that has at least: one joint on the
fire side, one joint located on the unexposed side, one straight section, one ’T’ section with an end cap at both openings.
7.2.5.3 Condition C—Fire exposure from the outside with hot gases entering the horizontal HVAC duct system through
unprotected openings, shall consist of the following minimum components assembled to meet the layout and the dimensional
requirements in Fig. 3 that has at least: one joint on the fire side, one joint located on the unexposed side, one straight section
having an end cap, and one of the sections in the furnace with two unprotected openings. The unprotected opening area shall total
50 % of the cross sectional area of the HVAC duct with the depth of the unprotected opening one half the depth of the HVAC duct,
and shall be located at least 20 in. (508 mm) from the fire-separating element through which the HVAC duct passes.
7.2.5.4 Condition D—Fire exposure from the outside with hot gases entering the inside of the vertical HVAC duct system
through unprotected openings, shall consist of the following minimum components assembled to meet the layout and the
dimensional requirements in Fig. 4 that has at least: one joint on the fire side, one joint located on the unexposed side, one straight
section having an end cap, and one of the sections in the furnace with two unprotected openings. The unprotected opening area
shall total 50 % of the cross sectional area of the HVAC duct with the width of the opening one half the width of the HVAC duct,
and shall be located at least 20 in. (508 mm) from the fire-separating element through which the HVAC duct passes.
7.2.6 All vertical sections of the HVAC duct not within the furnace shall be supported as in practice at the horizontal separating
element. The vertical section of an HVAC duct within the furnace shall have at least one joint. When equipped with a horizontal
transition of the HVAC duct inside the furnace, support the horizontal transition as in practice with a support system.
A = Width of HVAC Duct F = HVAC End
...