International Mechanical Code
The 2009 International Mechanical Code, incorporated by reference into the Washington State Building Code (WAC 51-52). Governs the design and installation of mechanical and HVAC systems.
International Mechanical Code (2009)
Washington adopted the 2009 IMC as WAC 51-52, effective July 1, 2010, with state amendments. It covers ventilation, exhaust systems, duct systems, combustion air, chimneys and vents, and heating and cooling equipment. The full text below is reproduced from the 2009 edition as incorporated into law, sourced from public.resource.org.
- Boilers, Water Heaters and Pressure Vessels
This chapter governs the installation, alteration, and repair of boilers, water heaters, and pressure vessels, ensuring compliance with specified standards and safety requirements.
- Chimneys and Vents
This chapter governs the installation, maintenance, repair, and approval of factory-built chimneys, chimney liners, vents, connectors, and the utilization of masonry chimneys.
- Combustion Air
This chapter establishes requirements for providing combustion air to fuel-burning appliances, referencing specific standards for solid fuel and oil-fired units while noting exclusions.
- Definitions
This chapter establishes the specific meanings for words and terms used throughout the International Mechanical Code (IMC) 2009.
- Duct Systems
This chapter outlines the requirements for the design, construction, and installation of duct systems used in air-conditioning, heating, ventilating, and exhaust applications.
- Exhaust Systems
This chapter governs the design, construction, and installation of various mechanical exhaust systems, including those for clothes dryers, cooking appliances, hazardous materials, and smoke control.
- Fuel Oil Piping and Storage
This chapter governs the design, installation, construction, and repair of fuel-oil storage and piping systems, including requirements for materials, joints, sizing, gauging, valves, and testing.
- General Regulations
This chapter outlines general regulations for the approval, installation, protection, location, support, access, condensate disposal, clearance, and load calculations of mechanical systems and appliances.
- Hydronic Piping
This chapter governs the construction, installation, alteration, and repair of hydronic piping systems, including those for heating, ventilation, and air-conditioning applications involving steam, hot water, and chilled water.
- Referenced Standards
- Refrigeration
This chapter governs the design, installation, construction, and repair of refrigeration systems, including refrigerant piping, pressure vessels, and pressure relief devices.
- Scope and Administration
Chapter 1 outlines the administrative framework for the Mechanical Code, defining its scope, enforcement responsibilities of the code official, requirements for permits and inspections, and the process for modifications and appeals.
- Solar Systems
This chapter governs the design, construction, installation, alteration, and repair of solar energy systems and related equipment for various heating and cooling applications.
- Specific Appliances, Fireplaces and Solid Fuel-burning Equipment
This chapter regulates the approval, design, installation, maintenance, and repair of various specific appliances, factory-built fireplaces, and solid fuel-burning equipment.
- Ventilation
This chapter establishes requirements for the ventilation of occupied building spaces, covering natural, mechanical, and specialized systems like those for parking garages and uninhabited spaces.