Rule 110-11-1-.27. International Mechanical Code (IMC), 2024 Edition with 2026 Georgia State Amendments

Rule 110-11-1-.27. International Mechanical Code (IMC), 2024 Edition with 2026 Georgia State Amendments

GEORGIA STATE MINIMUM STANDARD MECHANICAL CODE (INTERNATIONAL MECHANICAL CODE WITH GEORGIA STATE AMENDMENTS)

The INTERNATIONAL MECHANICAL CODE, 2024 Edition, published by the International Code Council, when used in conjunction with these Georgia State Amendments, shall constitute the official Georgia State Minimum Standard Mechanical Code.

GEORGIA STATE AMENDMENTS

CODE REFERENCE:

1. a) Replace all references to the ICC Electrical Code with references to the Georgia State Minimum Standard Electrical Code (National Electrical Code with Georgia State Amendments).

2. b) Replace all references to the International Energy Conservation Code (IECC) with references to the Georgia State Minimum Standard Energy Code (IECC with Georgia State Supplements and Amendments). The Georgia State Minimum Standard Energy Code shall be used for efficiency and coefficient of performance ratings of mechanical equipment.

   APPENDICES:

   Appendices are not enforceable unless they are specifically referenced in the body of the code or adopted by the Department of Community Affairs or the Authority Having Jurisdiction.

   SCOPE:

   The provisions of the Georgia State Minimum Standard Mechanical Code shall regulate the design, installation, maintenance, alteration and inspection of mechanical systems that are permanently installed and utilized to provide control of environmental conditions and related processes within buildings. This code shall also regulate those mechanical systems, system components, equipment and appliances specifically addressed herein. The installation of fuel gas distribution piping and equipment, fuel gas-fired appliances and fuel gas-fired appliance venting system shall be regulated by the Georgia State Minimum Standard Gas Code (International Fuel Gas Code with Georgia Amendments).

   Exception #1: Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories above grade with separate means of egress and their accessory structures shall comply with the Georgia State Minimum Standard One- and Two-Family Dwellings Code (International Residential Code for One- and Two- Family Dwellings with Georgia State Amendments).

   Exception #2: The following table titled 'Codes Reference Guide' establishes specific primary and supplementary code applications and is to be applied by the Authority Having Jurisdiction.

   CODES REFERENCE GUIDE Area Primary Supplement Occupancy Classification LSC IBC Building Construction Types, including allowable height, allowable building areas, and the requirements for sprinkler protection related to minimum building construction types. IBC LSC Means of Egress LSC NONE Standpipes IBC IFC Interior Finish LSC NONE HVAC Systems IMC NONE Vertical Openings LSC NONE Sprinkler Systems minimum construction standard LSC NONE Fire Alarm Systems LSC NONE Smoke Alarms and Smoke Detection Systems State Statute and LSC NONE Portable Fire Extinguishers IFC NONE Cooking Equipment LSC and NFPA 96 NONE Fuel Fired Appliances IFGC NFPA 54 Liquid Petroleum Gas NFPA 58 NFPA 54 Compressed Natural Gas NFPA 52 NONE

   GEORGIA STATE MINIMUM

   REQUIREMENTS FOR BOILERS/WATER HEATERS AND PRESSURE VESSELS

   The State's minimum requirements for boilers/water heaters and pressure vessels over 200,000 BTU/h (58.61 kW), 210 degrees Fahrenheit or 120 gallons capacity shall be established by O.C.G.A. Title 25, Chapter 15 and the Rules and Regulations of the Office of Insurance and Safety Fire Commissioner.

   *Revise the International Mechanical Code, 2024 Edition, as follows:

   CHAPTER 1

   SCOPE AND ADMINISTRATION

   *Delete Chapter 1 'Scope and Administration' without substitution. Chapter 1 to remain in the Code as a reference and guide for local governments in the development of their own Administrative Procedures.

   (Effective January 1, 2026)

   CHAPTER 3

   GENERAL REGULATIONS

   SECTION 301

   GENERAL

   *Revise Section 301.1 'Scope' to read as follows:

   301.1

   Scope. This chapter shall govern the approval and installation of all equipment and appliances that comprise parts of the building mechanical systems regulated by this code. (Effective January 1, 2026) *Revise Section 301.2 'Energy utilization' to read as follows:

   301.2

   Energy utilization. Heating, ventilating and air-conditioning systems of all structures shall be designed and installed for efficient utilization of energy in accordance with the International Energy Conservation Code. Cooling towers installed in new construction shall be in compliance with ASHRAE, Standard 90.1. (Effective January 1, 2026) *Revise Section 301.7 'Listed and labeled' to read as follows:

   301.7

   Listed and labeled. Appliances regulated by this code shall be listed and labeled for the application in which they are installed and used, unless otherwise approved. Exception to remain unchanged. (Effective January 1, 2026) *Add new Section 301.19 'Related fire codes' to read as follows:

   301.19

   Related fire codes. Any reference to the International Fire Code and/or NFPA standards in any chapter of this code shall be to the latest edition as adopted and amended by the Georgia Insurance and Safety Fire Commissioner. (Effective January 1, 2026) SECTION 306 ACCESS AND SERVICE SPACE *Revise Section 306.3 'Appliances in attics' to add new exception #3 to read as follows:

   306.3

   Appliances in attics.Exceptions: 3. In Residential Occupancies, attics containing appliances or mechanical equipment service shall be accessible by pull-down stairs or other permanent steps and at a minimum be sized to allow the removal of the largest appliance. (Effective January 1, 2026) CHAPTER 4 VENTILATION SECTION 401 GENERAL *Revise section 401.2 'Ventilation required' to read as follows:

   401.2

   Ventilation required. Every occupied space shall be ventilated by natural means in accordance with Section 402 or by mechanical means in accordance with Section 403. Where the air infiltration rate in a dwelling unit is less than three air changes per hour when tested with a blower door at a pressure of 0.2-inch water column (50 Pa) in accordance with the Georgia State Minimum Standard Energy Code, the dwelling unit shall be ventilated by mechanical means in accordance with Section 403. Ambulatory care facilities and Group I-2 occupancies shall be ventilated by mechanical means in accordance with Section 407. (Effective January 1, 2026) *Add new Section 401.7 'Alternative ventilation procedures' to read as follows:

   401.7

   Alternative ventilation procedures. As an alternative to Chapter 4, the following shall be permitted: 1. Ventilation Rate Procedure, Natural Ventilation Procedure or Indoor Air Quality Procedure, as prescribed by ASHRAE 62.1. Software programs to calculate outdoor ventilation air may be used to demonstrate ASHRAE 62.1 compliance, as approved by authority having jurisdiction. 2. A combination of ASHRAE 62.1 and ANSI/ASHRAE/ASHE Standard 170 may be utilized for different occupancy types within a single building. (Effective January 1, 2026) CHAPTER 5 EXHAUST SYSTEMS SECTION 501 GENERAL *Revise Section 501.3 'Exhaust discharge' Exception #1 to read as follows:

   501.3

   Exhaust discharge.Exceptions: 1. Whole-house ventilation-type attic fans shall be permitted to discharge into the ventilated attic space of dwelling units having private attics, provided the installed system meets paragraph 501.4 requirements for pressure equalization. (Effective January 1, 2026) SECTION 505 DOMESTIC COOKING EXHAUST EQUIPMENT *Add new Section 505.3.1 'Exhaust ducts for domestic range hoods installed in commercial applications' to read as follows:

   505.3.1

   Exhaust Ducts for domestic range hoods installed in commercial applications. Exhaust ducts for domestic range hoods installed in commercial applications including I-1 and I-2 occupancies shall be vented to the outside and shall be constructed of (a) Type B vent, or (b) smooth wall duct constructed of galvanized or stainless steel with a minimum duct thickness of 0.0157 inches (0.40 mm) or constructed of aluminum or copper with a minimum duct thickness of 0.023 inches (0.58mm). (Effective January 1, 2026) *Add new Section 505.9 'Commercial installations of domestic systems' to read as follows:

   505.9

   Commercial installations of domestic systems. Commercial installations of domestic systems shall comply with the current Life Safety Code NFPA 101 and 96 standards as adopted and amended by the Georgia Insurance and Safety Fire Commissioner. (Effective January 1, 2026) SECTION 506 COMMERCIAL KITCHEN HOOD VENTILATION SYSTEM DUCTS AND EXHAUST EQUIPMENT *Delete Section 506.1 'General' and substitute the following:

   506.1

   General. The State's minimum requirements for Type I commercial kitchen hood ventilation system ducts and exhaust equipment shall be designed, constructed and installed in accordance with the Life Safety Code NFPA 101 and NFPA 96 as adopted and amended by the Georgia Insurance and Safety Fire Commissioner. Other commercial kitchen hood ventilation system ducts and exhaust equipment shall comply with the requirements of this section. (Effective January 1, 2026) SECTION 507 COMMERCIAL KITCHEN HOODS *Delete Section 507.1 'General' and substitute the following:

   507.1

   General. The State's minimum requirements for Type I commercial kitchen hoods shall be designed, constructed and installed in accordance with the Life Safety Code NFPA 101 and NFPA 96 as adopted and amended by the Georgia Insurance and Safety Fire Commissioner. Other commercial kitchen hoods shall comply with the requirements of this section. (Effective January 1, 2026) *Delete Section 507.1.2 'Domestic cooking appliances used for commercial purposes' without substitution. (Effective January 1, 2026) *Delete Section 507.2.11 'Fire suppression systems' and substitute the following:

   507.2.11

   Fire suppression systems. The State's minimum requirements for fire suppression systems for commercial cooking equipment shall be established by the Life Safety Code NFPA 101 and NFPA 96 as adopted and amended by the Georgia Insurance and Safety Fire Commissioner. (Effective January 1, 2026) CHAPTER 6 DUCT SYSTEMS SECTION 606 SMOKE DETECTION SYSTEMS CONTROL *Rename Section 606.2.1 'Return air systems' and revise to read as follows:

   606.2.1

   Supply air systems. Smoke detectors shall be installed in supply air systems with a design capacity greater than 2,000 cfm (0.9m3/s), in the supply air duct downstream of any filters, fan motors, outdoor air connections, and upstream of any branch connections or decontamination equipment and appliances. Exception: Smoke detectors are not required in the supply air system where all portions of the building served by the air distribution system are protected by area smoke detectors connected to a fire alarm system in accordance with NFPA 72. The area smoke detection system shall comply with Section 606.4. (Effective January 1, 2026) *Revise Section 606.2.2 'Common supply and return air systems' to read as follows:

   606.2.2

   Common supply and return air systems. Where multiple air-handling systems share common supply or return air ducts or plenums with a combined design capacity greater than 2,000 cfm (0.9m3/s), the supply air system shall be provided with smoke detectors in accordance with Section 606.2.1. Exception: Individual smoke detectors shall not be required for each fan-powered unit, provided that such units do not have an individual design capacity greater than 2,000 cfm (0.9m3/s) and will be shut down by activation of one of the following: 1. Smoke detectors required by Sections 606.2.1 and 606.2.3. 2. An approved area smoke detector system located in the common plenum(s) serving such units. 3. An area smoke detector system as prescribed in the exception to Section 606.2.1. In all cases, the smoke detectors shall comply with sections 606.4 and 606.4.1. (Effective January 1, 2026) *Revise Section 606.4.1 'Supervision' first sentence to read as follows:

   606.4.1

   Supervision. The duct smoke detectors shall be connected to a fire alarm system where a fire alarm system is required by the Life Safety Code NFPA 101 and NFPA 72 as adopted and amended by the Georgia Insurance and Safety Fire Commissioner. (Effective January 1, 2026) CHAPTER 9 SPECIFIC APPLIANCES, FIREPLACES AND SOLID FUEL-BURNING EQUIPMENT SECTION 908 COOLING TOWERS, EVAPORATIVE CONDENSERS AND FLUID COOLERS * Revise Section 908.1 'General' to read as follows:

   908.1

   General. A cooling tower used in conjunction with an air-conditioning appliance shall be installed in accordance with the manufacturer's installation instructions. Factory-built cooling towers shall be listed in accordance with UL 1995 or UL/CSA 60335-2-40. The standards related to high efficiency cooling towers shall include without limitation the minimum standards prescribed by the ASHRAE, Standard 90.1. (Effective January 1, 2026) SECTION 917 COOKING APPLIANCES *Revise Section 917.1 'Cooking appliances' to add new Exception to read as follows: Exception: Listed and labeled commercial cooking appliances may be installed in dwelling units and domestic kitchens when such installation is designed by a Georgia Licensed Professional Engineer and accepted by the local authority having jurisdiction. (Effective January 1, 2026) *Delete Section 917.2 'Domestic appliances' without substitution. (Effective January 1, 2026) CHAPTER 10 BOILERS, WATER HEATERS AND PRESSURE VESSELS SECTION 1001 GENERAL *Revise Section 1001.1 'Scope' to add the following at the end of the first paragraph:

   1001.1

   Scope. ...and pressure vessels. The State's minimum requirements for boilers/water heaters and pressure vessels over 200,000 BTU/h (58.61 kW), 210 degrees Fahrenheit or 120 gallons capacity shall be established by O.C.G.A. Title 25, Chapter 15 and the as adopted and amended Rules and Regulations of the Office of Insurance and Safety Fire Commissioner. (Effective January 1, 2026) CHAPTER 11 REFRIGERATION SECTION 1101 GENERAL * Delete section 1101.1.1 'Refrigerants other than ammonia' and substitute the following:

   1101.1.1

   Refrigerants other than ammonia. Refrigeration systems using a refrigerant other than ammonia shall comply with this chapter, the International Fire Code, and either ASHRAE 15 or ASHRAE 15.2, as applicable. Refrigeration systems containing carbon dioxide as the refrigerant shall also comply with IIAR CO2. (Effective January 1, 2026) SECTION 1105 MACHINERY ROOM, GENERAL REQUIREMENTS *Renumber Section [F] 1105.3 'Refrigerant detector' as 1105.3 and revise to read as follows:

   1105.3

   Refrigerant detector. Refrigerant detectors in machinery rooms shall be provided as required in accordance with ASHRAE 15. (Effective January 1, 2026) SECTION 1106 MACHINERY ROOM, SPECIAL REQUIREMENTS *Renumber Section [F] 1106.5 'Remote controls' as 1106.5 and revise to read as follows:

   1106.5

   Remote controls. Remote control of the mechanical equipment and appliances located in the machinery room shall be provided as required in accordance with ASHRAE 15. (Effective January 1, 2026) *Renumber Section [F] 1106.6 'Emergency signs and labels' as 1106.6 and revise to read as follows:

   1106.6

   Emergency signs and labels. Refrigeration units and systems shall be provided with approved signs, charts and labels in accordance with ASHRAE 15. (Effective January 1, 2026) SECTION 1107 PIPING MATERIAL *Revise 1107.4 'Piping materials standards' to read as follows:

   1107.4

   Piping materials standards. Refrigerant pipe shall conform to one or more of the standards listed in Table 1107.4. For refrigeration systems used in residential occupancies serving only a single dwelling unit or sleeping unit, refrigerant piping and tubing shall be limited to aluminum, copper, and copper alloy. The exterior of the pipe shall be protected from corrosion and degradation. (Effective January 1, 2026) *Revise 1107.5 'Pipe fittings' to read as follows:

   1107.5

   Pipe fittings. Refrigerant pipe fittings shall be approved for installation with the piping materials to be installed, and shall conform to one of more of the standards listed in Table 1107.5 or shall be listed and labeled as complying with UL 207. For refrigeration systems used in residential occupancies serving only a single dwelling unit or sleeping unit, refrigerant fittings shall be limited to aluminum, copper, copper alloys, stainless steel, and steel. (Effective January 1, 2026) SECTION 1109 REFRIGERANT PIPE INSTALLATION * Revise 1109.3.2 'Shaft ventilation' to read as follows:

   1109.3.2

   Shaft ventilation. Required refrigerant pipe shafts with systems using Group A2L or B2L refrigerant shall be naturally or mechanically ventilated. Refrigerant pipe shafts with one or more systems using any Group A2, A3, B2 or B3 refrigerant shall be continuously mechanically ventilated and shall include a refrigerant detector. The shaft ventilation exhaust outlet shall comply with Section 501.3.1. Naturally ventilated shafts shall have a pipe, duct, or conduit not less than 4 inches (102 mm) in diameter that connects to the lowest point of the shaft and extends to the outdoors. The pipe, duct or conduit shall be level or pitched downward to the outdoors. Mechanically ventilated shafts shall have a minimum airflow velocity in accordance with Table 1109.3.2. The mechanical ventilation shall be continuously operated or activated by a refrigerant detector. Systems utilizing a refrigerant detector shall activate the mechanical ventilation at a maximum refrigerant concentration of 25 percent of the lower flammable limit of the refrigerant. The detector, or a sampling tube that draws air to the detector, shall be located in an area where refrigerant from a leak will concentrate. The shaft shall not be required to be ventilated for double-wall refrigerant pipe where the interstitial space of the double-wall pipe is vented to the outdoors. For refrigeration systems used in residential occupancies serving only a single dwelling unit or sleeping unit, shaft ventilation shall not be required where the pipe or tube is continuous without fittings in the shaft. (Effective January 1, 2026) * Revise section 1109.2.5 'Refrigerant pipe shaft' Exception 1 and 2 to read as follows:

   1109.2.5

   Refrigerant pipe shafts. Refrigerant piping that penetrates two or more floor/ceiling assemblies shall be enclosed in a fire-resistance-rated shaft enclosure. The fire-resistance-rated shaft enclosure shall comply with Section 713 of the International Building Code. Exceptions: 1. Refrigeration systems using R-718 refrigerant (water). 2. Piping in a direct refrigeration system where the refrigerant quantity does not exceed the limits of Table 1103.1 for the smallest occupied space through which the piping passes. 3. Piping located on the exterior of the building where vented to the outdoors. (Effective January 1, 2026) CHAPTER 13 FUEL OIL PIPING AND STORAGE SECTION 1301 GENERAL *Revise Section 1301.1 'Scope' to add the following at the end of the paragraph:

   1301.1

   Scope. ...International Fire Code. The State's minimum requirements for fuel oil piping and storage shall be as established by the Georgia State Minimum Fire Safety Standards and the as adopted and amended Rules and Regulations of the Georgia Insurance and Safety Fire Commissioner. Any areas not addressed by the Georgia State Minimum Fire Safety Standards shall be regulated by this chapter. (Effective January 1, 2026) CHAPTER 14 SOLAR THERMAL SYTEMS SECTION 1402 DESIGN AND INSTALLATION *Revise Section 1402.4 'Protection from freezing' to read as follows:

   1402.4

   Protection from freezing. System Components shall be protected from damage by freezing of heat transfer liquids at the lowest ambient temperatures that will be encountered. Freeze... (Remainder of paragraph to remain unchanged) (Effective January 1, 2026) SECTION 1403 HEAT TRANSFER FLUIDS *Add new Section 1403.2.1 'Protection of drains' to read as follows:

   1403.2.1

   Protection of drains. Drains serving heat transfer fluids over 140°F (60°C) or which are toxic or corrosive shall be protected in accordance with the requirements of The International Plumbing Code. (Effective January 1, 2026) CHAPTER 15 REFERENCED STANDARDS *Revise Chapter 15 'Referenced Standards' to add the following: ASHRAE Standard reference number Title Referenced in code section number 15.2-2022 Safety Standard for Refrigeration Systems in Residential Applications 1101.1.1, GA Amendments (Effective January 1, 2026)

Authority: O.C.G.A. § 8-2-20 et seq.

History. Original Rule entitled "International Mechanical Code (IMC), 2012 Edition with 2014 Georgia State Amendments" adopted. F. Nov. 13, 2013; eff. Jan. 1, 2014, as specified by the Agency.

Amended: New title "International Mechanical Code (IMC), 2012 Edition with 2014 and 2015 Georgia State Amendments." F. Nov. 12, 2014; eff. Jan. 1, 2015, as specified by the Agency.

Amended: New title "International Mechanical Code (IMC), 2018 Edition with 2020 Georgia State Amendments." F. Oct. 30, 2019; eff. Jan. 1, 2020, as specified by the Agency.

Amended: New title "International Mechanical Code (IMC), 2018 Edition with 2020 and 2024 Georgia State Amendments." F. Oct. 11, 2023; eff. Jan. 1, 2024, as specified by the Agency.

Amended: New title "International Mechanical Code (IMC), 2024 Edition with 2026 Georgia State Amendments." F. Dec. 2, 2025; eff. Jan. 1, 2026, as specified by the Agency.