The mechanical code regulates the design, installation, maintenance, alteration, and inspection of mechanical systems, including heating systems, ventilating systems, steam and hot water heating systems, process piping, boilers and pressure vessels, appliances utilizing gas, liquid or solid fuel, chimneys and vents, mechanical refrigeration systems, fireplaces, barbecues, incinerators, crematories, fire suppression systems and system utilizing solar or geothermal energy. The 2012 Michigan Mechanical Code went into effect September 27, 2013. Provisions for one- and two-family dwellings are included in the 2009 Michigan Residential Code.
A mechanical contractor's license with the appropriate classification is required for the performance of installing, altering, or servicing the following: (1) Hydronic heating and cooling and process piping, (2) HVAC equipment, (3) Ductwork, (4) Refrigeration, (5) Limited Heating service, (6) Unlimited Heating Service, (7) Limited Refrigeration and air conditioning service (8) Unlimited refrigeration and air conditioning service, (9) Fire Suppression, (10) Specialty. However, an owner of a single family swelling who will occupy or occupies the residence may perform the work without a license.
Except for replacement of minor parts, mechanical work shall not be started until a permit for such work has been issued by the appropriate enforcing agency. A homeowner must secure a permit for work they are performing at their residence, and mechanical contractors are responsible for permits on work they are performing on behalf of an owner.
Permits are not required for portable equipment (heating, ventilation, cooling units, evaporative cooler, gas burners with less than 30,000 Btu/hr.), self-contained refrigeration equipment and window-type air conditioners of not more than 1.5 hp, and oil burners not requiring connection to a flue (oil stoves, heaters equipped with wick).
Permits for steam or vapor boilers carrying a pressure of not more than 15 p.s.i.g., which are located in private residences or in apartment houses of less than 6 families must be secured by a licensed mechanical contractor classified in the hydronic heating and cooling, and process piping classifications.
