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Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Uniform+Mechanical+Code%22">"Uniform Mechanical Code"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Uniform+Mechanical+Code%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Uniform+Mechanical+Code%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Uniform+Mechanical+Code%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Uniform+Mechanical+Code%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Uniform+Mechanical+Code%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">August 2020</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444"><table class="box-Primary_sources plainlinks metadata ambox ambox-content ambox-Primary_sources" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" 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href="https://www.google.com/search?as_eq=wikipedia&q=%22Uniform+Mechanical+Code%22">"Uniform Mechanical Code"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Uniform+Mechanical+Code%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Uniform+Mechanical+Code%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Uniform+Mechanical+Code%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Uniform+Mechanical+Code%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Uniform+Mechanical+Code%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">August 2020</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> </div> </div><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox vcard"><caption class="infobox-title fn org">IAPMO</caption><tbody><tr><td colspan="2" class="infobox-subheader"><div>International Association of Plumbing and Mechanical Officials</div></td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.6em;">Founded</th><td class="infobox-data note">1926</td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.6em;">Location</th><td class="infobox-data label"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style><div class="plainlist"><ul><li><span class="country-name"><a href="/wiki/United_States" title="United States">United States</a></span></li></ul></div></td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.6em;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Key people</div></th><td class="infobox-data">David Viola, CEO; David Gans, President; Steve Panelli, Vice President; Hugo Aguilar, Vice President of Codes and Standards; Zalmie Hussein, Code Development Administrator</td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.6em;">Website</th><td class="infobox-data"><a rel="nofollow" class="external text" href="https://www.iapmo.org/">www.iapmo.org</a></td></tr></tbody></table> <p>The <b>Uniform Mechanical Code</b> (<b>UMC</b>) is a model code developed by the <a href="/wiki/IAPMO" title="IAPMO">International Association of Plumbing and Mechanical Officials</a> (<a href="/wiki/IAPMO" title="IAPMO">IAPMO</a>) to govern the installation, inspection and maintenance of <a href="/wiki/HVAC" class="mw-redirect" title="HVAC">HVAC</a> (heating, <a href="/wiki/Ventilating" class="mw-redirect" title="Ventilating">ventilating</a> and <a href="/wiki/Air-conditioning" class="mw-redirect" title="Air-conditioning">air-conditioning</a>) and <a href="/wiki/Refrigeration" title="Refrigeration">refrigeration</a> systems. It is designated as an American National Standard. </p><p>The UMC is developed using the <a href="/wiki/American_National_Standards_Institute" title="American National Standards Institute">American National Standards Institute</a>'s (ANSI) consensus development procedures. This process brings together volunteers representing a variety of viewpoints and interests to achieve consensus on mechanical issues. </p><p>The UMC is designed to provide consumers with safe mechanical systems while, at the same time, allowing latitude for innovation and new technologies. The public at large is encouraged to provide input for the development process. The code is updated every three years. A code development timeline and other relevant information are available at IAPMO's website. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Uniform_Mechanical_Code&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In 1926, a group of Los Angeles <a href="/wiki/Plumbing" title="Plumbing">plumbing</a> inspectors recognized that there were no uniform requirements for the installation and maintenance of plumbing systems. At that time, heating was done by <a href="/wiki/Boilers" class="mw-redirect" title="Boilers">boilers</a> that piped the heat to <a href="/wiki/Radiators" class="mw-redirect" title="Radiators">radiators</a>. Efficient air conditioning was not available. Widely divergent practices and the use of many different, often conflicting, <a href="/wiki/Plumbing_code" title="Plumbing code">plumbing codes</a> by local jurisdictions led to plumbing systems that were incompatible and potentially dangerous.<sup id="cite_ref-IAPMO_1-0" class="reference"><a href="#cite_note-IAPMO-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> This underscored the necessity of developing a model code that could be uniformly applied across jurisdictions. </p><p>Two years later, the city adopted the first version of a uniform plumbing and mechanical code developed by the Los Angeles City Plumbing Inspectors Association (LACPIA) and based on the input from a committee of plumbing inspectors, master and <a href="/wiki/Journeyman" title="Journeyman">journeyman</a> plumbers, and <a href="/wiki/Mechanical_engineer" class="mw-redirect" title="Mechanical engineer">mechanical engineers</a>, assisted by <a href="/wiki/Public_utilities" class="mw-redirect" title="Public utilities">public utility</a> companies and the plumbing industry. </p><p>The ultimate product of this effort, the first Uniform Mechanical Code, was published by IAPMO, the new name for LACPIA, which was adopted in 1966 when the scope of mechanical work grew beyond plumbing and became more readily available in residential applications.<sup id="cite_ref-IAPMO_1-1" class="reference"><a href="#cite_note-IAPMO-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> in 1967. Over the last fifty years, this voluntary code has been adapted by jurisdictions not only throughout the United States, but internationally as well. The consensus development process was first applied to the 2003 edition. </p><p>The 2012 edition is the fourth edition developed under the ANSI consensus process. Contributions to the content of the code were made by every segment of the <a href="/wiki/Building_industry" class="mw-redirect" title="Building industry">building industry</a>, including such diverse interests as consumers, enforcing authorities, installers/maintainers, insurance, labor, manufacturers, research/standards/testing laboratories, special experts, and users. The 2012 Uniform Mechanical Code is supported by the <a href="/w/index.php?title=American_Society_of_Sanitary_Engineering&action=edit&redlink=1" class="new" title="American Society of Sanitary Engineering (page does not exist)">American Society of Sanitary Engineering</a> (ASSE), the <a href="/w/index.php?title=Mechanical_Contractors_Association_of_America&action=edit&redlink=1" class="new" title="Mechanical Contractors Association of America (page does not exist)">Mechanical Contractors Association of America</a> (MCAA), the <a href="/w/index.php?title=Plumbing-Heating-Cooling_Contractors_National_Association&action=edit&redlink=1" class="new" title="Plumbing-Heating-Cooling Contractors National Association (page does not exist)">Plumbing-Heating-Cooling Contractors National Association</a> (PHCC-NA), the <a href="/wiki/United_Association" title="United Association">United Association</a> (UA) and the <a href="/wiki/World_Plumbing_Council" title="World Plumbing Council">World Plumbing Council</a> (WPC). </p> <div class="mw-heading mw-heading2"><h2 id="2018_Edition">2018 Edition</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Uniform_Mechanical_Code&action=edit&section=2" title="Edit section: 2018 Edition"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Major changes to the 2018 UMC include: </p> <ul><li>New requirements for <a href="/wiki/Piping" title="Piping">piping</a>, <a href="/wiki/Tubing_(material)" class="mw-redirect" title="Tubing (material)">tubing</a>, balancing, <a href="/wiki/Louver" title="Louver">louvers</a>, protection of piping, mechanical systems and <a href="/wiki/Ductwork" class="mw-redirect" title="Ductwork">ductwork</a></li> <li>New provisions for <a href="/wiki/Evaporative_cooler" title="Evaporative cooler">evaporative cooling systems</a></li> <li>Refrigeration port protection requirement</li> <li>New requirements for piping, tubing and fittings used in <a href="/wiki/Hydronics" title="Hydronics">hydronic systems</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="2021_Edition">2021 Edition</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Uniform_Mechanical_Code&action=edit&section=3" title="Edit section: 2021 Edition"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Significant changes to the 2021 UMC include: </p> <ul><li>New Appendix F – Geothermal Energy Systems</li> <li>New guards and rails requirements for installation of equipment and appliances on roofs</li> <li>New ventilation requirements for transient and nontransient occupancies</li> <li>New ventilation requirements for <a href="/wiki/Indoor_air_quality" title="Indoor air quality">indoor air quality</a> for residential occupancies</li> <li>Revisions to the requirements for air ducts, including factory-made air ducts and dampers</li> <li>New provisions for factory-built grease ducts</li> <li>New provisions for refrigeration systems, including pressure-limiting devices and hydrostatic expansion</li> <li>Revisions to the sizing requirements for natural gas and propane piping systems</li> <li>Modifications to the pressure rating requirements for hydronic piping applications</li> <li>New requirements for fuel gas piping appliance shutoff valves, test pressure and overpressure protection devices</li> <li>New tube fastener provisions for radiant heating and cooling</li> <li>New requirements for residential compressed natural gas (CNG) fueling systems</li> <li>New fire-extinguishing equipment and carbon monoxide detection requirements for exhaust systems</li></ul> <div class="mw-heading mw-heading2"><h2 id="Content">Content</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Uniform_Mechanical_Code&action=edit&section=4" title="Edit section: Content"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>Chapter 1 - Administration</li> <li>Chapter 2 - Definitions</li> <li>Chapter 3 - General Regulations</li> <li>Chapter 4 - Ventilation Air</li> <li>Chapter 5 - Exhaust Systems (Part 1: Environmental <a href="/wiki/Air_duct" class="mw-redirect" title="Air duct">Air Ducts</a> and Product Conveying Systems; Part 2: <a href="/wiki/Extractor_hood" class="mw-redirect" title="Extractor hood">Commercial Hoods and Kitchen Ventilation</a>)</li> <li>Chapter 6 - Duct Systems</li> <li>Chapter 7 - Combustion Air</li> <li>Chapter 8 - Chimney and Vents</li> <li>Chapter 9 - Installation of Specific Appliances</li> <li>Chapter 10 - Boilers and Pressure Vessels</li> <li>Chapter 11 - Refrigeration (Part 1: Refrigeration Systems; Part 2: <a href="/wiki/Cooling_tower" title="Cooling tower">Cooling Towers</a>)</li> <li>Chapter 12 - Hydronics (Part 1: Steam and Water Piping; Part 2: Hydronic Panel Heating Systems)</li> <li>Chapter 13 - Fuel Gas Piping (Part 1: Fuel Piping; Part 2: Fuel Supply: Manufactured/<a href="/wiki/Mobile_home_park" class="mw-redirect" title="Mobile home park">Mobile Home Parks</a> and Recreational Vehicle Parks)</li> <li>Chapter 14 - Process Piping</li> <li>Chapter 15 - Solar Energy Systems</li> <li>Chapter 16 - Stationary Power Plants</li> <li>Chapter 17 - Referenced Standards</li> <li>Appendix A - Residential Plans Examiner Review Form for HVAC System Design</li> <li>Appendix B - Procedures to be Followed to Place Gas Equipment in Operation</li> <li>Appendix C - Installation and Testing of Oil (Liquid) Fuel-Fired Equipment</li> <li>Appendix D - Fuel Supply: Manufactured/Mobile Home Parks and Recreational Vehicle Parks</li> <li>Appendix E - Sustainable Practices</li> <li>Appendix F - Geothermal Energy Systems</li> <li>Appendix G - Sizing of Venting Systems and Outdoor Combustion and Ventilation Opening Design</li> <li>Appendix H - Example Calculation of Outdoor Air Rate</li></ul> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Uniform_Mechanical_Code&action=edit&section=5" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/IAPMO" title="IAPMO">IAPMO</a></li> <li><a href="/wiki/IAPMO_Standards" title="IAPMO Standards">IAPMO Standards</a></li> <li><a href="/wiki/IAPMO_R%26T" title="IAPMO R&T">IAPMO R&T</a></li> <li><a href="/wiki/Uniform_Codes" title="Uniform Codes">Uniform Codes</a></li> <li><a href="/wiki/Uniform_Plumbing_Code" title="Uniform Plumbing Code">Uniform Plumbing Code</a></li> <li><a href="/wiki/Uniform_Swimming_Pool,_Spa_and_Hot_Tub_Code" title="Uniform Swimming Pool, Spa and Hot Tub Code">Uniform Swimming Pool, Spa and Hot Tub Code</a></li> <li><a href="/wiki/Uniform_Solar_Energy_and_Hydronics_Code" title="Uniform Solar Energy and Hydronics Code">Uniform Solar Energy and Hydronics Code</a></li> <li><a href="/wiki/Building_officials" title="Building officials">Building officials</a></li> <li><a href="/wiki/Building_inspection" title="Building inspection">Building inspection</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Uniform_Mechanical_Code&action=edit&section=6" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-IAPMO-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-IAPMO_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-IAPMO_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">"1926 to 2006: Eight Decades of Excellence," Copyright © 2007 by IAPMO, p. 47-9</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External 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