60

Years of
Experience

About
MicroMetl

Founded in Indianapolis, IN in 1965, MicroMetl has engineered HVAC products to keep up with the demands of code and efficiency required change all the while keeping an eye on ease of field installation.

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What Drives Us

Industry Leading Top Quality
Products

Born in Indianapolis in 1965 as General Sheet Metal, MicroMetl began by crafting duct systems—and evolved to become the largest independent U.S. manufacturer of HVAC accessories. Over the decades, we’ve expanded coast to coast, driven by innovation in energy-efficient solutions and a deep commitment to our partners.

Today, with manufacturing facilities in Indianapolis, IN, Sparks, NV, and Longview, TX, we continue to grow as a family-owned business—powered by service, engineering ingenuity, and the pursuit of excellence in the commercial HVAC industry.

To be the trusted leader in HVAC accessory innovation—empowering our customers with smarter, greener, and more reliable airflow solutions that redefine industry standards and build environments that work harder, smarter, and longer.

We continue to invest in advanced manufacturing technologies and state-of-the-art software to stay ahead of the curve—ensuring we deliver unmatched precision, efficiency, and performance in every product we make.

We deliver high-performance commercial HVAC accessories through innovation, expert craftsmanship, and customer-driven service—empowering our partners to build smarter, more efficient environments.

To ensure long-term value and reliability, we stay at the forefront of evolving national and local code requirements, engineering every product to meet today’s standards and anticipate tomorrow’s demands.

A Legacy of Innovation and Quality

MicroMetl has a rich history of innovation and growth.
Our timeline showcases key milestones that define our legacy in the HVAC industry.

1965

Humble Beginnings in Indianapolis

General Sheet Metal (GSM) is founded by the Booher family in Indianapolis, IN, manufacturing and installing sheet metal duct systems for the local construction industry—specializing in downturn plenums.

1971

Breaking New Ground in HVAC Accessories

GSM pioneers the use of downturn plenums and roof curbs, producing them in small volumes for early OEM partners—marking the beginning of a new category in HVAC support products.

1973

Enter the Economizer Era

As the concept of “free cooling” gains momentum, GSM rebrands as MicroMetl Corporation and begins designing its own economizers—cementing its role in energy-saving innovation for commercial HVAC systems.

1984

Recognized for Rapid Growth

MicroMetl earns a spot on the Inc. 500 list of fastest-growing companies in the U.S. for two consecutive years, thanks to energy-efficient product innovation and exceptional service.

1992

Ownership Transitions

The company experiences two ownership transfers (1987 and 1992), both reinforcing MicroMetl’s vision for scaling operations and continuing its legacy of quality and customer focus.

1994

Expanding Westward

To better serve West Coast partners, MicroMetl opens a new manufacturing facility in Sparks, NV, enabling faster lead times and regional support. Also in 1994: MicroMetl pioneers Amada sheet metal programming technology, pushing production accuracy and efficiency forward.

2000

Lights-Out Manufacturing Begins

MicroMetl invests in automated “lights-out” production using Amada equipment—introducing continuous, unattended operation to maximize output and precision.

2005

Manufacturing in Texas

A third facility opens in Longview, TX, to meet rising demand. Strategically positioned near major OEMs, Longview becomes a hub for large-scale HVAC accessory production.

2012

Title 24 Compliance

In response to California’s evolving energy codes, MicroMetl launches Title 24-compliant damper products, helping contractors and OEMs meet new regulatory demands.

2014

Partnership with TRUMPF

MicroMetl transitions to TRUMPF laser technology, replacing older Amada machines with advanced precision cutting systems. The first TRUMPF laser is installed, beginning a new era of manufacturing power.

2016

Ultra Low Leak Technology Launch

The company debuts its Ultra Low Leak economizer technology, setting a new bar for HVAC efficiency and performance—particularly in regulated and energy-sensitive markets.

2019

Full TRUMPF Cell Integration

All three facilities upgrade to TRUMPF Trumatic cells, standardizing high-efficiency production capabilities nationwide and ensuring consistency across the U.S. market.

2022

Blade Rollformer Investment

MicroMetl enhances sheet metal forming with the addition of a Blade Rollformer, further streamlining part fabrication and improving cycle time across product lines.

2023

Full Curb Rollformer Cell in Texas

MicroMetl installs a dedicated curb rollformer cell in Longview, boosting capacity for rooftop curb production and reinforcing its leadership in HVAC accessory manufacturing.

2025

MicroMetl Turns 60

In 2025, MicroMetl celebrates six decades of manufacturing excellence and industry leadership. Our 60-year journey reflects a legacy of innovation, dedication, and the people who helped build our success.