|
Buckley Rumford Fireplaces International Mechanical Code 5/23/12 ________________________ Do large metal chimneys meet code? That turns out to be a good question. The International Mechanical code (IMC) was just amended in the 2006 edition to clarify the issue. See below. The 2003 IMC, however, required all factory-built metal chimneys to "comply with the Type HT requirements of UL 103" yet no manufacturer we could find makes a chimney tested to that standard. The NFPA 211 code has long recognized that open fireplaces are safer than closed combustion chamber appliances and allowed the UL 103 (not the HT) standard to apply. See NFPA 211 on Reduced Standards for Chimneys Venting Open Fireplaces Now that language has been added to the IMC as well. See below. I'm so disappointed that we can't drive up and down California replacing all the "illegal metal chimneys" with masonry chimneys. Actually this is old stuff for us. We were instrumental in getting the BOCA code in 1989 to allow single wall unlisted liners in masonry chimneys, arguing that open fireplaces are safer than closed combustion chamber stoves. See 1989 BOCA code changes. That provision was in the BOCA code for several years until the BIA asked us to support them removing the language. Maybe we shouldn't have agreed. A lower standard for safer open fireplace chimneys may be a good thing and may have implications for any UL listed masonry chimney we might develop - or if we want to restore the use of historic chimneys for fireplaces. Jim Buckley, with help from Glen Edgar from Selkirk and Greg Cress from the ICC. Here's the code:
FACTORY-BUILT CHIMNEYS 805.1 Listing. Factory-built chimneys shall be listed and labeled and shall be installed and terminated in accordance with the manufacturerÕs installation instructions. 805.2 Solid fuel appliances. Factory-built chimneys installed in dwelling units with solid fuel-burning appliances shall comply with the Type HT requirements of UL 103 and shall be marked "Type HT" and "Residential Type Building Heating Appliance Chimney."
1) Chimneys for use with open combustion chamber fireplaces shall comply with the requirements of UL 103 and shall be marked "Residential Type Building Heating Appliance Chimney." 2) Chimneys for use with open combustion chamber appliances installed in buildings other than dwelling units shall comply with the requirements of UL 103 and shall be marked "Building Heating Appliance Chimney" or "Residential Type Building Heating Appliance Chimney." 805.4 Support. Where factory-built chimneys are supported by structural members, such as joists and rafters, such members shall be designed to support the additional load. 805.5 Medium-heat appliances. Factory-built chimneys for medium-heat appliances producing flue gases having a temperature above 1,000 F (538 C), measured at the entrance to the chimney, shall comply with UL 959. 805.6 Decorative shrouds. Decorative shrouds shall not be installed at the termination of factory-built chimneys except where such shrouds are listed and labeled for use with the specific factory-built chimney system and are installed in accordance with Section 304.1.
SECTION 806 806.1 General. Metal chimneys shall be constructed and installed in accordance with NFPA 211. _____________________ UL 103 Factory-Built Chimneys for Residential Type and Building Heating Appliances 1 Scope 1.1 These requirements cover factory-built chimneys intended for venting gas, liquid, and solid-fuel fired residential-type appliances and building heating appliances in which the maximum continuous flue-gas outlet temperatures do not exceed 1000¡F (538¡C). Factory-built chimneys are intended for installation in accordance with the Standard for Chimneys, Fireplaces, Vents, and Solid-Fuel Burning Appliances, NFPA 211, and in accordance with codes such as the BOCA National Mechanical Code, the Standard Mechanical Code, and the Uniform Mechanical Code. They are intended for installation inside or outside of buildings or both, in a manner that provides a vertical (30 degree maximum offset) conduit or passageway to transport flue gases to the outside. 1.2 The chimneys covered by these requirements comply with either a 1700¡F (927¡C) flue-gas temperature test or a 2100¡F (1149¡C) flue-gas temperature test, at the manufacturer's option. ..... 36.4 A chimney assembly complying with the requirements of Section 23, Temperature Test - 2100¡F (1149¡C) Flue Gases, shall be permanently marked "Type HT ". This marking shall be affixed to each chimney pipe section, ceiling support and wall penetration assembly (such as a thimble). When attached to a part, such as a ceiling support or wall penetration assembly, the marking shall be placed so as to be identifiable from the room in which the heating appliance is installed after installation of the assembly.
After numerous fires caused by non-listed decorative shrouds interfering with the cooling air flow of air cooled metal chimneys listed to UL 127, the current code now prohibits unlisted shrouds or terminations on any metal chimnmey. Many of our Rumford fireplaces are vented by Class A insulated metal chimneys listed to UL 103. These chimneys are not air cooled and therefore not rendered unsafe by terminating them with non-listed decorative shrouds - like our clay chimney pots. Here is Selkirk's shroud guidlines kindly provided by Glen Edgar. Jack Arnold UL Listed copper pots. Email: Pat Kegan And here are our proposed code changes for the next code change cycle.
SECTION 303 303.1 General. Equipment and appliances shall be located as required by this section, specific requirements elsewhere in this code and the conditions of the equipment and appliance listing. 303.2 Hazardous location. Appliances shall not be located in a hazardous location unless listed and approved for specific installation. 303.3 Prohibited locations. Fuel-fired appliances shall not be located in, or obtain combustion air from, any of the following rooms or spaces:
2. Bathrooms. 3. Toilet rooms. 4. Storage closets. 5. Surgical rooms. Exception: This section shall not apply to the following appliances:
2. Solid fuel-fired appliances, provided that the room is not a confined space and the building is not of unusually tight construction. 3. Appliances installed in a dedicated enclosure in which all combustion air is taken directly from the outdoors, in accordance with Section 703. Access to such enclosure shall be through a solid door, weather-stripped in accordance with the exterior door air leakage requirements of the International Energy Conservation Code and equipped with an approved self-closing device.
International Fuel Gas Code (IFGC) SECTION 303 APPLIANCE LOCATION 303.3 Prohibited locations. Fuel-fired appliances shall not be located in, or obtain combustion air from, any of the following rooms or spaces:
2. Bathrooms. 3. Toilet rooms. 4. Storage closets. 5. Surgical rooms. Exceptions:
2. Listed vented gas fired room heaters, listed vented decorative gas appliances and listed decorative gas-fired appliances for installation in vented solid fuel burning fireplaces, provided that the room is not a confined space and the building is not of unusually tight construction.
Commentary by Jim Buckley While the IMC and the IFGC are very similar the IMC deals with all fireplaces and so specifically excepts "Solid fuel-fired appliances" while the NFGC code relates to gas fireplaces only and is silent about wood-burning fireplaces. So wood-burning fireplaces are permitted in bedrooms on two conditions: (a) they must not be in a "confined space" and, (b) if "decorative gas-fired appliances for installation in vented solid fuel burning fireplaces" (gas logs) are installed they must be "listed". Presumably the concern is that a wood-burning fireplace, should it smoke, would wake up the sleeping inhabitants and, in any event, soon would go out if not refueled. Gas fireplaces, on the other hand, are more dangerous in that they could spill odorless carbon monoxide into the bedroom and the gas would stay on indefinitely even while the inhabitants were sleeping. A "confined space" is defined elsewhere in the NFGC as a space (or room) with less than 50 cubic feet per 1,000 btu input of the appliance. The Victorian Fireplace website has useful information about gas fireplaces in bedrooms.
|
Back to Codes and Standards
Buckley Rumford Fireplaces
Copyright 1995 - 2012 Jim Buckley
All rights reserved.
webmaster