Construction Services & Inspections

HVAC and Mechanical Permit Information

Heating, Venting & Air Conditioning (HVAC)/Mechanical permits are the mechanism used to comply with the requirements found in the Minnesota Mechanical and Fuel Gas Code. The purpose of the code is to establish the minimum acceptable level of safety and to protect life and property from the potential dangers associated with the installation and operation of mechanical systems. The code also protects the personnel that install, maintain, service and replace the systems and appliances addressed by this code. The HVAC permit must be taken out on ePlace by a Mechanical Contractor bonded by the Minnesota Department of Labor & Industry(DOLI).

Plans are to be prepared by a Minnesota licensed mechanical engineer and must be submitted at the time of HVAC/mechanical permit application. The design professional responsible for the project must approve mechanical plans for compatibility with their work before the application is submitted. An information sheet with Commercial Plan Review Guidelines can be found here. The HVAC Commercial Intake Checklist will help you gather the required document in preparation for applying on ePlace.

Commercial HVAC work may not begin until the HVAC permit has been issued. Inspections for commercial HVAC work will not be scheduled until the HVAC permit is issued. Click here for a handy flow chart describing the process from application to start of HVAC work.

Permits

HVAC permits are needed for the following:

  • Heating appliances such as a furnace, boiler, space heater, or gas fireplaces
  • Ductwork, radiant heat, in-floor heat, or baseboard heat installation
  • Air to air exchangers, Air-conditioning installation. Refrigeration equipment installation
  • High pressure steam/gas heating installation and all mechanical appliances and equipment.

HVAC items/projects not needing a permit:

  • portable heating, venting, or cooling units (Mostly items you can plug into a standard electrical outlet),
  • Self-contained refrigeration systems containing ten pounds (4.5kg) or less of refrigerant or that are actuated by motors of one horsepower (0.75kW) or less.
  • Replacement parts of heating, venting or cooling appliances

This is not intended to be a complete list of work that does or does not require a permit. See MN State Building Code Chapter 1300.0120.

Hoods

Do you need a Type I or II Hood?

When domestic cooking appliances are used in commercial buildings, Type I or II hoods are required in accordance with amended Minnesota Mechanical Code Section 507. We have a helpful worksheet here to help you understand what type of hood the code will require for your project.

Commercial Hood Suppression Systems

You’ll find information about Commercial Hood Suppression Systems here.

Plan Review

Commercial HVAC projects need a plan review except for simple like for like equipment replacements (Must be under 400,000 BTU’s) or as determined by the HVAC Reviewer/Inspector. Plans designed, stamped, and signed by a Mechanical Engineer Licensed in the State of Minnesota, the commercial energy compliance worksheet with supporting documentation, and the building’s Life Safety Plan need to be uploaded when applying for the permit. A site plan based on a boundary survey may be needed for a new building, addition or if equipment is placed at the exterior of the building. The Mechanical Engineer should work with the Architect for both the Site plan and Life Safety plan. HVAC systems may require screening or setbacks from property lines and building openings. The Life Safety plan helps in determining where required dampers, fire walls, fire barriers, or fire partitions are located. The energy worksheet information and any Change of Occupancy that would trigger an HVAC upgrade should also be coordinated between the design professionals.

Energy Code

The 2024 Minnesota Commercial Energy Code is now being used. Make sure all compliance documentation (Such as Com-Check) are using the 2024 Minnesota Energy Code based on ASHRAE90.1 2019.

Permits - The basic rules for all HVAC permits are above, under commercial work. The application for one & two family homes can be taken out by the owner of the home or a mechanical contractors with a registered mechanical bond at the Minnesota Department of Labor & Industry(DOLI).

Hoods – All of the rules for commercial hoods can apply to residential scenarios. When industrial hoods are placed in one & two family homes, the commercial rules for those need to be followed. 

Plan Review – Generally there is no plan review for residential HVAC permits.

Energy Code- The 2020 Minnesota Residential Energy Code is still being used for residential projects.

Inspections are scheduled by phone. Click here for information about inspections. To find the inspector’s phone number, for your project, click here search for the property on the City of Duluth map. Once the property is found, click and all of the inspector’s contact information for that area will pop up, Just scroll down until you get to the inspector for Mechanical/HVAC for most HVAC inspections or Residential Furnace & Boiler Replacements (Comfort Systems) for replacing those items in one & two family homes or townhouses.