Small Business Assistance - Permit Primer
Combustion
The Combustion category of emission sources includes devices such as boilers, furnaces, space heaters, emergency or back-up generators, dryers, or incinerators. These devices are sources of air pollutants when they burn gaseous (natural gas), liquid (fuel oil) or solid (coal or wood) fuels.
You Need to Determine If You Are Exempt
Each process in the list below has a certain exemption level (listed in the drop-down definition box that appears when clicking on each one) that your process must be less than to be exempt. If your process is not below those levels, or you cannot substitute materials or modify the process to bring it below those levels then you are not exempt and will need to apply for a construction permit.
(Click on the drop-down topic below to review the exemption level, then refer to the facts sheets that follow)
Topics with Clickable, Drop-down Exemption Levels
- External Combustion Furnaces
- Indirect Malt Dryers
- Emergency Electric Generators Powered by Internal Combustion Engines
Calculations Fact Sheet
To determine how to calculate your boiler rating, fuel heating value, fuel throughput and maximum theoretical emissions and discover whether you need to file an application for an air pollution construction permit, please review the following fact sheet:
Clean Air Facts: Combustion Sources Fact Sheet (PDF, 59 KB) (Exit DNR) 
If you've determined you are not exempt, please continue by clicking the "Not Exempt" button below. This link will take you to a pollution prevention option web page.
Small
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