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Family-owned and operated, Welzig Heating and Air exemplifies quality across our comprehensive range of residential and light commercial services. Our in-house sheet metal fabrication shop supports our dedication to better solutions to everyday challenges. We provide the resources, materials, and workmanship that not only fulfill your needs today but hold up to long-term wear and tear. Enjoy superior value from Welzig Heating and Air.

Sheet Metal Fabrication from the Experts

Working with galvanized steel, Welzig Heating and Air custom fabricates ductwork to perfectly suit the demands of the residence or facility, maximizing space savings, cost savings, energy efficiency, comfort, and air quality. By eliminating the middleman, we are able to avoid delays, miscommunication, and anything that might get in the way of the best possible process and end result.

Custom Sheet Metal for HVAC

Along with in-house sheet metal fabrication, Welzig Heating and Air includes welding capabilities and on-site services. Give us a call at (720) 336-3777 to discuss your project. Let us put our experience, knowledge, and insight to work for you. We’re happy to offer recommendations and tailor every aspect of the job to ideally achieve your goals. Welzig Heating and Air is where you find satisfaction guaranteed and prompt scheduling across Boulder, Longmont, Louisville, and Lafayette, CO.

Satisfied Customers
They Speak For Us

Bob came out to look at our swamp cooler and was remarkably helpful and professional. Not only did he give me a knowledgeable diagnosis, but he also taught me a lot in the process. We’ll be calling him for all future needs with our cooling system.


Our 23-year-old A/C system ran out of “borrowed time” and became too difficult to continue maintaining. With great advice from Casey Welzig,, we replaced the old system with a Bryant Evolution A/C system. Max Loustaunau and Seth Bernhardt did an excellent job with removing the old system and installing the new one. Both of them are great to work with — very professional and very personable. We are really amazed at how much better the new system works!


Dave Kaplan-Gomez and James Miltersen installed my new Tankless Water Heater. Both were polite and professional. Care was taken not to damage anything in my house which I really appreciated. I use Welzig for all my HVAC needs and highly recommend them.

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