2015 INTERNATIONAL FUEL GAS CODE COMMENTARY 3-1

SECTION 301 (IFGC)GENERAL

301.1 Scope. This chapter shall govern the approval andinstallation of all equipment and appliances that compriseparts of the installations regulated by this code in accordancewith Section 101.2.

This section states that this chapter governs theapproval and installation of all gas-fired equipmentand appliances that are regulated by the code. Sec-tion 101.2 establishes the scope of application of thecode (see commentary, Section 101.2).

301.1.1 Other fuels. The requirements for combustion anddilution air for gas-fired appliances shall be governed by Sec-tion 304. The requirements for combustion and dilution airfor appliances operating with fuels other than fuel gas shallbe regulated by the International Mechanical Code.

This code and the International Mechanical Code

(IMC) each have a combustion air chapter that isspecific to the fuels addressed in the respective code.

301.2 Energy utilization. Heating, ventilating and air-condi-tioning systems of all structures shall be designed andinstalled for efficient utilization of energy in accordance withthe International Energy Conservation Code.

This section states that all appliances and equipmentmust be designed and installed to use depletableenergy sources efficiently. The International EnergyConservation Code (IECC) is the applicable docu-ment for regulating the efficiency and performance ofappliances and heating, ventilating and air-condition-ing (HVAC) systems. Special applications such asprocess heating or cooling should be designed for themaximum energy efficiency attainable.

301.3 Listed and labeled. Appliances regulated by this codeshall be listed and labeled for the application in which theyare used unless otherwise approved in accordance with Sec-tion 105. The approval of unlisted appliances in accordancewith Section 105 shall be based on approved engineeringevaluation.

Gas-fired appliances must be listed and labeled by anapproved agency to show that they comply with the

applicable national standards. The code requires list-ing and labeling for appliances, such as boilers, fur-naces, space heaters, direct-fired heaters, cookingappliances, clothes dryers, rooftop HVAC units, etc.The code also requires listing for system componentsas specifically stated in the text addressing thosecomponents. The label is the primary, if not the only,assurance to the installer, the inspector and the enduser that a representative sample of an appliancemodel has been tested and evaluated by anapproved agency and has been determined to per-form safely and efficiently when installed and oper-ated in accordance with its listing.

Appliances must be listed and labeled for the appli-cation in which they are used, otherwise the installa-tion would be a misapplication of the appliance. Forexample, if an appliance is listed for indoor use onlyand is installed outdoors, this installation is a misap-plication of the appliance and serious malfunctionsand/or conditions could result. An appliance might bemarketed and installed for a particular purpose forwhich it was not tested and listed and this is what thissection intends to prohibit. Verifying that an appliancehas a testing agency label is only part of the code offi-cial’s responsibility. He or she must also verify thatthe listing from the testing agency includes the appli-cation at hand. The bottom line is, the use of an appli-ance must match the use for which the appliance wastested.

The presence of a label is part of the informationthat the code official considers when approving appli-ances. The only exception to the labeling requirementoccurs when the code official approves a specificappliance in accordance with the authority granted inSection 105.2.

Approval of unlabeled appliances must be basedon documentation that demonstrates compliance withapplicable standards or, where no product standardsexist, that the appliance is appropriate for theintended use and will provide the same level of per-formance as would be provided by listed and labeledappliances. A fundamental principle of the code is thereliance on the listing and labeling process to ensure

Chapter 3:General Regulations

General CommentsA fundamental principle of the code is its dependenceon the listing and labeling method of approval for appli-ances and equipment. Section 301.3 prohibits theinstallation of unlisted appliances except whereapproved in accordance with Section 105.

PurposeChapter 3 contains requirements for the safe and properinstallation of gas-fired equipment and appliances tohelp ensure protection of life and property.

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appliance performance; approvals granted in accor-dance with Section 105.2 must be well justified withsupporting documentation. To the code official, theinstaller and the end-user, very little is known aboutthe performance of an appliance that is not testedand built to an appliance standard.

301.4 Labeling. Labeling shall be in accordance with theprocedures set forth in Sections 301.4.1 through 301.4.2.3.

This section establishes the requirements for testingand labeling appliances by an approved agency.Included within this section are the requirements fortesting the product and for approval of the testingagency, the testing equipment and the personnel whoconduct the test. Also included is the information thatmust appear on a label.

301.4.1 Testing. An approved agency shall test a representa-tive sample of the appliances being labeled to the relevantstandard or standards. The approved agency shall maintain arecord of all of the tests performed. The record shall providesufficient detail to verify compliance with the test standard.

When an approved agency labels an appliance, theagency is ensuring that a representative sample ofthe appliance has been tested in accordance with anappropriate standard and has been determined toperform acceptably when installed and operated inaccordance with the appliance’s listing.

The basis for a label is the requirement for testing arepresentative, perhaps identical, sample of the appli-ance to indicate conformance to a required standard.This is an important premise in the code because acode official will consider the presence of a label inthe approval of an appliance. For this reason, theappliance must meet the requirements of the stan-dard. Because the appliance tested is installed andoperated in accordance with the manufacturer’sinstructions, these instructions must provide forproper installation and operation. This is importantbecause the code requires that the labeled appliancebe installed in accordance with the manufacturer’sinstructions, and operating instructions must be eitherattached to or shipped with each appliance.

There are numerous standards, not all of which arespecifically referenced in the code, applicable to vari-ous appliances and equipment. For this reason, theapproved agency determines the applicable stan-dards to be used for testing and then, in turn, as thebasis for labeling. Each standard contains safetyrequirements for a given appliance or piece of equip-ment and specifies tests that must be performed. Thelabeling agency is required to maintain sufficient doc-umentation to demonstrate compliance with the teststandard. The code official may require that copies ofthe test reports be submitted to determine the validityof the label.

Examples of standards that are used as a basis fortesting and labeling include:

• ANSI Z21.47, Gas-fired Central Furnaces;• ANSI Z83.8, Gas Unit Heaters; and

• UL 795, Commercial—Industrial Gas Heating Equipment.

301.4.2 Inspection and identification. The approved agencyshall periodically perform an inspection, which shall be in-plant if necessary, of the appliances to be labeled. Theinspection shall verify that the labeled appliances are repre-sentative of the appliances tested.

The approved agency whose identification insigniaappears on the label must perform periodic in-plantinspections. The primary objective of these inspec-tions is to determine that the manufactured product isequivalent to the sample that was tested. Becausethe label is good only for the products that weretested, the in-plant inspections are intended to dis-cover any design changes or production quality con-trol problems. If any discrepancies are found, that thelabeling agency would discontinue labeling of thatparticular product, and the manufacturer would berequired to resolve the problem and, if necessary,have the redesigned product retested before thelabeling process is resumed.

301.4.2.1 Independent. The agency to be approved shall beobjective and competent. To confirm its objectivity, theagency shall disclose all possible conflicts of interest.

As a part of the basis for a code official’s approval ofa particular labeling agency, the agency must demon-strate both its independence from the manufacturerof the product and its competence to perform therequired tests. The judgment of objectivity is linked tothe financial and fiduciary independence of theagency. The competence of the agency is judged byits experience, organization and the experience of itspersonnel. As a hypothetical example, the AcmeInspection Agency is performing testing for gas-firedfurnaces for the Real Hot Furnace Company. Aftersome investigation, both Acme and Real Hot arefound to be the subsidiaries of the same parent com-pany. The inspection agency and the manufacturerclearly have a relationship that presents the potentialfor conflict of interest, and the objectivity of theinspection agency is sufficiently questionable for thecode official to justify not approving Acme as a testingand labeling agency for equipment produced by theReal Hot Furnace Company.

301.4.2.2 Equipment. An approved agency shall have ade-quate equipment to perform all required tests. The equipmentshall be periodically calibrated.

Referring to the example in the commentary for Sec-tion 301.4.2.1, if the Acme Inspection Agency hadonly the facilities to test and label fire doors, theagency would not be qualified to test and label a gas-fired furnace. Although this example is oversimplified,the point is that the inspection agency must have allof the necessary equipment to perform the testingrequired by the applicable standard.

In addition to having the proper equipment, theagency must maintain records of the maintenanceand calibration of their equipment to demonstrate that

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the equipment can be relied on to produce accurate,consistent and reproducible results. Testing appara-tus, instruments and equipment must often be capa-ble of measurements using very small units ofmeasure within a specified tolerance. To produceaccurate, dependable readings and reliable testresults, testing apparatus, equipment and instru-ments must be routinely calibrated to a fixed refer-ence. Having the proper testing equipment can bejust as important as the competence of the testingpersonnel.

301.4.2.3 Personnel. An approved agency shall employexperienced personnel educated in conducting, supervisingand evaluating tests.

The competence of an inspection agency is based onthe agency having the proper equipment to performthe test, as stated in Section 301.4.2.2, and also onthe experience and abilities of its personnel. The bestcalibrated equipment can produce accurate resultsonly when operated by experienced personnel whoare trained to conduct, supervise and evaluate tests.For example, consider a newly formed agency thathas employed individuals who do not have experi-ence related to the testing to be conducted and havenot been adequately trained. The capabilities andexperience of supervisory personnel overseeing theirwork is also important.

301.5 Label information. A permanent factory-appliednameplate(s) shall be affixed to appliances on which shallappear in legible lettering, the manufacturer’s name or trade-mark, the model number, serial number and, for listed appli-ances, the seal or mark of the testing agency. A label shallinclude the hourly rating in British thermal units per hour(Btu/h) (W); the type of fuel approved for use with the appli-ance; and the minimum clearance requirements.

This section requires that the label be a metal plate,tag or other permanent label. In general, label materi-als other than metal tags or plates usually consist ofmaterial that is similar in appearance to a decal, andthe label, its adhesive and the printed informationmust be durable and water resistant. Because of theimportant information given by a label, the label isintended to be permanent, not susceptible to damageand legible for the life of the appliance to which it isattached. The standards that appliances are tested tousually specify the required label performance crite-ria, the method of attachment and the required labelinformation. The code requires that the label beaffixed permanently and prominently on the applianceor equipment and specifies the information that mustappear on the label. The manufacturer may berequired by the relevant standard or may voluntarilyprovide additional information on the label. Commen-tary Figures 301.5(1) and 301.5(2) show typical appli-ance labels.

301.6 Plumbing connections. Potable water supply andbuilding drainage system connections to appliances regulated

by this code shall be in accordance with the InternationalPlumbing Code.

Plumbing connections to appliances and equipmentregulated by the code must be in accordance with theInternational Plumbing Code (IPC).

Section 624.2 of the code requires that combina-tion domestic water heating and hydronic supplywater heating units be listed and installed accordingto their listing and manufacturer’s instructions.

Hydronic systems normally require a means ofsupplying fill and makeup water to replace any waterlost to evaporation, leakage or intentional draining.Where direct connections are made to the potablewater supply, the connections must be isolated fromthe potable water source. This requirement isintended to protect the potable water system fromcontamination by backflow when a direct connectionis made to a hydronic system.

Hydronic systems are normally pressurized, con-tain nonpotable water and fluids and can contain con-ditioning chemicals or antifreeze solutions. Low-temperature hydronic fluids and cooling towers havealso been associated with disease-causing organ-isms such as the Legionnaires’ disease bacterium.The potable water system must be protected frompotential contamination resulting from connection tohydronic systems, water-wash filter systems, coolingtowers, solar systems, water-cooled heat exchang-ers, cooking appliances, ice makers, humidifiers,evaporative coolers, etc.

In addition, water heaters are part of the potablewater distribution system and, therefore, must complywith both the code and the IPC. A water heater instal-lation is complex in that it has a fuel or power supply;a chimney or vent connection, if fuel-fired; a combus-tion air supply, if fuel-fired; connections to the plumb-ing potable water distribution system and controlsand devices to prevent a multitude of potential haz-ards from conditions such as excessively high tem-peratures, pressures and ignition failure.

It is not uncommon for jurisdictions to issue bothplumbing and mechanical permits for water heaterinstallations or to require that the installer be licensedin both the plumbing and mechanical trades whenperforming such installations (see commentary, Sec-tion 624). Water heaters are clearly under the pur-view of both plumbing and fuel gas codes. Thissection also refers to the IPC for the drainage associ-ated with mechanical appliances and equipment,such as those addressed in Section 307.

301.7 Fuel types. Appliances shall be designed for use withthe type of fuel gas that will be supplied to them.

Appliances are usually designed by the manufacturerto operate on one specifically designated type of fuel.An element of information used for the approval ofappliances is the label, which ensures that the appli-ance has been tested in accordance with a valid stan-

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dard and determined to perform acceptably wheninstalled and operated in accordance with the appli-ance listing (see commentary, Section 301.5). Thefuel used in the appliance test must be the type offuel specified by the manufacturer.

301.7.1 Appliance fuel conversion. Appliances shall not beconverted to utilize a different fuel gas except where com-plete instructions for such conversion are provided in theinstallation instructions, by the serving gas supplier or by theappliance manufacturer.

A mismatch between an appliance and a fuel will cre-ate an extremely hazardous condition that can beavoided by examining the appliance label. When anappliance is converted to a different type of fuel, theoriginal label that appears on the appliance is no lon-ger valid. Because the original approval of the appli-ance is based in part on the label, the appliance is nolonger approved for use. Fuel conversion kits willinclude a replacement label.

Many gas appliances are listed and labeled formore than one fuel, most commonly natural gas andliquefied petroleum (LP) (propane). Such appliancescan be converted from one fuel to the other using amanufacturer’s conversion kit and following instruc-tions provided by the manufacturer. These conver-sions must be done only with the approval of the codeofficial to make sure that the instructions are com-plied with and the safety of the original installation ismaintained. Fuel conversions that are not performedcorrectly can adversely affect the performance ofburners, the venting of combustion gases and theproper clearance to combustibles.

Once a conversion has been completed, a supple-mental label must be installed to update the informa-tion contained on the original label, thereby alertingany service personnel to the modifications that havebeen made.

Fuel-fired appliances are designed to operate witha maximum and minimum heat energy input capacity.

Figure 301.5(1)TYPCIAL LABEL FOR A CATEGORY I GAS-FIRED FURNACE

(Figure courtesy of the Trane Company, an American Standard Company)

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In accordance with the appliance manufacturer’sinstructions, this capacity might need to be fieldadjusted to suit the elevation because of the changein air density at different elevations. Alteration of heatenergy input beyond the allowable limits can result inhazardous overfiring or underfiring. Either conditioncan cause operation problems that include overheat-ing, vent failure, corrosion, poor draft and poor com-bustion. Input adjustments for different elevations aredictated by the appliance manufacturer and are notaddressed in the code, other than by Section 305.1.

301.8 Vibration isolation. Where means for isolation ofvibration of an appliance is installed, an approved means forsupport and restraint of that appliance shall be provided.

Where vibration isolation connections are used inducts and piping and where equipment is mountedwith vibration dampers, support is required for theducts, piping and equipment to maintain positioningand alignment and to prevent stress and strain on thevibration connectors and dampers.

301.9 Repair. Defective material or parts shall be replaced orrepaired in such a manner so as to preserve the originalapproval or listing.

Repair work must not alter the nature of appliancesand equipment in a way that would invalidate the list-ing or conditions of approval. For example, replace-ment of safety control devices with different devicescould alter the design and operation of an appliancefrom that intended by the manufacturer and the listingagency.

301.10 Wind resistance. Appliances and supports that areexposed to wind shall be designed and installed to resist thewind pressures determined in accordance with the Interna-tional Building Code.

Installations of equipment and appliances that aresubject to wind forces must be designed to resistthose forces. The wind pressures must be based onthe wind provisions in the code. The wind pressurerequirements are based on the exposure of the build-ing and wind speeds for that region.

Figure 301.5(2)ROOFTOP HVAC UNIT LABEL

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[BS] 301.11 Flood hazard. For structures located in floodhazard areas, the appliance, equipment and system installa-tions regulated by this code shall be located at or above theelevation required by Section 1612 of the InternationalBuilding Code for utilities and attendant equipment.

Exception: The appliance, equipment and system installa-tions regulated by this code are permitted to be locatedbelow the elevation required by Section 1612 of the Inter-national Building Code for utilities and attendant equip-ment provided that they are designed and installed toprevent water from entering or accumulating within thecomponents and to resist hydrostatic and hydrodynamicloads and stresses, including the effects of buoyancy, dur-ing the occurrence of flooding to such elevation.

In flood hazard areas, mechanical systems, equip-ment and appliances must be elevated above the ele-vation specified in the International Building Code

(IBC). Exposure to water can damage mostmechanical system components as well as causeserious appliance and equipment malfunctions. Forexample, the majority of appliance manufacturersrequire the replacement of safety controls or entireappliances that have been submerged in floodwaters. See FEMA 348 for additional guidance.

The exception to this section provides criteria forplacing specific equipment below the required eleva-tion. To do so, the equipment must be designed toprevent the entry or accumulation of water. Standardequipment that typically is installed at-grade is notdesigned to withstand the entry of water and wouldnot meet the requirements of this exception.

301.12 Seismic resistance. When earthquake loads are appli-cable in accordance with the International Building Code, thesupports shall be designed and installed for the seismic forcesin accordance with that code.

This code requires building systems to be designedfor specified seismic forces. This section referencesthe detailed equipment and component seismic sup-port requirements contained in the code to bringthese requirements to the attention of the design pro-fessional and the permit applicant.

Equipment piping must be braced for earthquakeloads as stated in the code. The failure of the sup-ports for these components has been shown to be athreat to health and safety in geographical areaswhere moderate- to high-magnitude earthquakesoccur. The code specifies the geographical locationswhere earthquake design is required for certain pip-ing and equipment and the size of the componentsthat must be braced.

301.13 Ducts. Ducts required for the installation of systemsregulated by this code shall be designed and installed inaccordance with the International Mechanical Code.

Chapter 6 of the IMC governs duct systems used forthe movement of environmental air, governing theconstruction, installation, alteration, maintenance andrepair of these systems (see the definition of “Ductsystem” in Chapter 2).

301.14 Rodentproofing. Buildings or structures and thewalls enclosing habitable or occupiable rooms and spaces inwhich persons live, sleep or work, or in which feed, food orfoodstuffs are stored, prepared, processed, served or sold,shall be constructed to protect against rodents in accordancewith the International Building Code.

This section states the requirements to preventrodent infestation of a building. Efforts must be madeto protect the annular spaces around openings inexterior walls. The annular spaces can be sealed byany effective method, but the primary methods usedare to fill the annular space with a sealant material orto place a metal collar around the penetrating pipe,duct, etc. The collar material must be durable for theweather exposure and strong enough to prevent therodents from chewing through and entering the build-ing.

Effort must also be made to cover ventilation andcombustion air openings with wire mesh material toprevent the entry of rodents through the opening.

301.15 Prohibited location. The appliances, equipment andsystems regulated by this code shall not be located in an ele-vator shaft.

The code views an elevator shaft as an unnecessarilyrisky location for fuel-gas system components. Thereis a potential for leaks in fuel-gas system equipmentand piping, which would release fuel gas into theshaft, creating a hazardous condition. Because theelevator is often relied on for fire-fighting access aswell as egress for those with disabilities, the shaftmust be maintained free from contaminants andpotential hazards that could render the elevator inop-erative or unsafe for the occupants. The location offuel-gas-fired equipment in an elevator shaft couldalso create access problems for service of the gas-fired equipment and the elevator equipment.

SECTION 302 (IFGC)STRUCTURAL SAFETY

[BS] 302.1 Structural safety. The building shall not beweakened by the installation of any gas piping. In the processof installing or repairing any gas piping, the finished floors,walls, ceilings, tile work or any other part of the building orpremises which is required to be changed or replaced shall beleft in a safe structural condition in accordance with therequirements of the International Building Code.

The installation of fuel gas systems must notadversely affect the structural integrity of the buildingcomponents. The code dictates the structural safetyrequirements that must be applied to any structuralportion of the building that is penetrated, altered orremoved during the installation, replacement or repairof fuel gas systems.

[BS] 302.2 Penetrations of floor/ceiling assemblies andfire-resistance-rated assemblies. Penetrations of floor/ceil-ing assemblies and assemblies required to have a fire-resis-