Notice of Intended Action

State mechanical code—adoption of 2018 International Mechanical Code by reference, 61.2

Untitled document

ARC 4448C


Notice of Intended Action

Proposing rule making related to the state mechanical code and providing an opportunity for public comment

The Plumbing and Mechanical Systems Board of the Department of Public Health hereby proposes to amend Chapter 61, "State Mechanical Code," Iowa Administrative Code.

Legal Authority for Rule Making

This rule making is proposed under the authority provided in Iowa Code section 105.4.

State or Federal Law Implemented

This rule making implements, in whole or in part, Iowa Code section 105.4.

Purpose and Summary

The proposed amendments include the adoption by reference of the International Mechanical Code, 2018 Edition. The Board previously adopted the 2015 edition of the International Mechanical Code (IMC). The Board is required to adopt the most recent version of the IMC by law. In addition, the proposed amendments incorporate other clarifications to the state mechanical code that were suggested by public comment. These changes are relatively minor technical changes to better align the IMC with current practice.

Fiscal Impact

This rule making has no fiscal impact to the State of Iowa.

Jobs Impact

After analysis and review of this rule making, no impact on jobs has been found.


Any person who believes that the application of the discretionary provisions of this rule making would result in hardship or injustice to that person may petition the Board for a waiver of the discretionary provisions, if any, pursuant to the Board's general waiver provisions contained in 641—Chapter 31.

Public Comment

Any interested person may submit written comments concerning this proposed rule making. Written comments in response to this rule making must be received by the Board no later than 4:30 p.m.on June 11, 2019. Comments should be directed to:

Kane Young

Department of Public Health

Lucas State Office Building

321 East 12th Street

Des Moines, Iowa 50319


Public Hearing

A public hearing at which persons may present their views orally or in writing will be held as follows:

June 11, 2019

3 to 4 p.m.

Room 518

Lucas State Office Building

Des Moines, Iowa

Persons who wish to make oral comments at the public hearing may be asked to state their names for the record and to confine their remarks to the subject of this proposed rule making.

Any persons who intend to attend the public hearing and have special requirements, such as those related to hearing or mobility impairments, should contact the Board and advise of specific needs.

Review by Administrative Rules Review Committee

The Administrative Rules Review Committee, a bipartisan legislative committee which oversees rule making by executive branch agencies, may, on its own motion or on written request by any individual or group, review this rule making at its regular monthly meeting or at a special meeting. The Committee's meetings are open to the public, and interested persons may be heard as provided in Iowa Code section 17A.8(6).

The following rule-making action is proposed:

Amend rule 641—61.2(105) as follows:

641—61.2(105) Adoption by reference. The provisions of the International Mechanical Code, 2015 2018 edition, published by the International Code Council, 4051 West Flossmoor Road, Country Club Hills, IL 60478, are hereby adopted by reference as the requirements for 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, with the following amendments:

61.2(1) Delete section 101.1.

61.2(2) In section 101.2, delete the phrase "International Fuel Gas Code" and insert in lieu thereof "NFPA 54, National Fuel Gas Code, 2015 edition; NFPA 58, Liquefied Petroleum Gas Code, 2014 edition; the provisions of 661—Chapter 226; and the state plumbing code."

61.2(3) Delete sections 103, 104, 105, 106, 107, 108, 109, and 110 and sections therein. section 103 and insert in lieu thereof the following new section 103.1:

103.1 Local authority. Local jurisdictions may administer the permit, inspection, testing, and enforcement provisions contained in this code. Permit, inspection, testing, and enforcement provisions contained in this code shall not be administered by the Plumbing and Mechanical Systems Board or the state.

61.2(4) Amend section 304.11 by deleting the last sentence and inserting in lieu thereof the following new exception:

Exception: Guards are not required where permanent fall arrest/restraint anchorage connector devices that comply with ANSI/ASSE Z 359.1 are affixed for use during the entire lifetime of the roof covering. The devices shall be evaluated for possible replacement when the entire roof covering is replaced. The devices shall be placed not more than 10 feet (3048 mm) on center along hip and ridge lines and placed not less than 10 feet (3048 mm) from roof edges and the open sides of walking surfaces.

61.2(5) Delete section 306.2 and insert in lieu thereof the following new section:

306.2 Appliances in rooms and closets. Rooms and closets containing appliances shall be provided with a door and an unobstructed passageway measuring not less than 36 inches wide and 80 inches high. A level service space not less than 30 inches deep and 30 inches wide shall be present at the front service side of the appliance with the door open.

61.2(4) 61.2(6) Delete section 401.1 and insert in lieu thereof the following new section:

401.1 Scope. This chapter shall govern the ventilation of spaces within a building intended to be occupied. These buildings shall meet either the requirements of ASHRAE Standard 62.1, "Ventilation for Acceptable Indoor Air Quality," 2013 2016 edition, published by the American Society of Heating, Refrigeration, and Air-Conditioning Engineers, 1791 Tullie Circle N.E., Atlanta, GA 30329, or the requirements contained in this chapter. Mechanical exhaust systems, including exhaust systems serving clothes dryers and cooking appliances; hazardous exhaust systems; dust, stock, and refuse conveyor systems; subslab soil exhaust systems; smoke control systems; energy recovery ventilation systems; and other systems specified in Section 502 shall comply with Chapter 5.

61.2(5) 61.2(7) Add the following footnote "i" related to the gym, stadium, arena (play area) category of the sports and amusement occupancy classification in Table 403.3 403.3.1.1, Minimum Ventilation Rates:

i.When combustion equipment is intended to be used on the playing surface, additional dilution ventilation and/or source control shall be provided.

61.2(8) Add the following footnote "j" to Table 403.3.1.1 anywhere the term "smoking lounges" appears:

j.For ventilation purposes, "smoking" includes both combustible tobacco products and accessories and electronic smoking devices and accessories.

61.2(6) 61.2(9) Delete section 504.8.2 and insert in lieu thereof the following new section:

504.8.2 Duct Installation installation. Exhaust ducts shall be supported at 4-foot (1219 mm) intervals and secured in place. The insert end of the duct shall extend into the adjoining duct or fitting in the direction of airflow. Ducts shall not be joined by screws or similar fasteners that protrude into the inside of the duct.

61.2(10) Delete subsection 506.3.13.3 and insert in lieu thereof the following new subsection:

506.3.13.3 Termination location. Exhaust outlets shall be located not less than 10 feet (3048 mm) horizontally from parts of the same or contiguous buildings, adjacent buildings and adjacent property lines and shall be located not less than 10 feet (3048 mm) above the adjoining grade level. Exhaust outlets shall be located not less than 20 feet horizontally/vertically from or not less than 5 feet above air intake openings and operable doors and windows into any building.

61.2(11) Delete section 508.1.1 and insert in lieu thereof the following new section:

508.1.1 Makeup air temperature. All kitchen makeup air systems shall be verified by a certified TAB (testing and balance) contractor to heat makeup air to within 10 degrees of room temperature set point. The TAB contractor shall be certified by NEBB, TABB, or other certifying organization as approved by the Authority Having Jurisdiction.

61.2(12) Amend section 601.5 by adopting new paragraphs "9" through "11" as follows:

9.A central return shall not be placed within a bedroom.

10.An undercut door shall not constitute a return air path.

11.Return air openings shall be located at least 18 inches from supply air openings. Air throw shall be directed away from return air openings to reduce short cycling of air. Exception: Factory-made concentric duct terminations.

61.2(13) Delete subsection 603.6.1.1 and insert in lieu thereof the following new subsection:

603.6.1.1 Duct length. Flexible air ducts shall only be used at the final connection to the air terminal device and shall be limited to 8 feet.

61.2(14) Delete section 603.12 and insert in lieu thereof the following new section:

603.12 Condensation. Provisions shall be made to prevent the formation of condensation on the exterior of any duct. Bathroom, domestic kitchen and dryer exhaust vents ducted to an outside wall shall be insulated at least 10 feet back from the outside wall. However, if the duct is in an unconditioned space, the entire duct shall be insulated.

61.2(15) Delete section 604.3 and insert in lieu thereof the following new section:

604.3 Coverings and linings. Covering and linings, including adhesives where used, shall have a flame spread index of not more than 25 and a smoke-development index of not more than 50, when tested in accordance with ASTM E84 or UL 723, using the specimen preparation and mounting procedures of ASTM E2231. Duct coverings and linings shall not flame, glow, smolder or smoke when tested in accordance with ASTM C411 at the temperature to which they are exposed in service. The testing temperature shall not fall below 250ºF (121ºC). Coverings and linings shall be listed and labeled. The use of an air gap to meet R-value requirements for duct insulation shall be prohibited.

61.2(7) 61.2(16) Delete appendices A and appendix B.

61.2(8) 61.2(17) Delete all references to the "International Plumbing Code" and insert in lieu thereof "state plumbing code."

Public Health Department

Closed For Comments

This notice is now closed for comments. Collection of comments closed on 6/11/2019.

Official Document

  • State mechanical code—adoption of 2018 International Mechanical Code by reference, 61.2
  • Published on 5/22/2019
  • 552 Views , 0 Comments
  • Notice of Intended Action

The official published PDF of this document is available from the Iowa General Assembly’s Administrative Rules page.

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View the Iowa Administrative Bulletin for 5/22/2019.

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Rule 641-61.2


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