about us

About Us

Air Control Techniques, P.C.

Established in 1993 in Cary, North Carolina

Founded in 1993, Air Control Techniques, P.C. is an air emission testing and monitoring company headquartered in Cary, NC. We serve clients throughout the U.S., Canada, and South America. We are proud of the decades-long relationships we have with many of our industrial clients.

Current Initiatives

Air Control Techniques is constantly working on innovative solutions in air quality testing to meet the needs of our clients.

  • We’re working with NSSGA to develop methods to minimize the adverse impact of EPA’s AERR rule on mineral industry sources.
  • The EPA’s current policy of classifying 100% of particulate as PM2.5 for sources in moisture-saturated and droplet-laden stacks creates large biases to higher-than-true reported PM2.5 emissions. We’re developing a new test method to minimize this bias by directly measuring filterable PM2.5 in wet stacks.
  • We have developed detailed greenhouse gas emission inventory programs to help industrial operators evaluate their emissions and respond to regulatory agencies, as well as investors and the public.
  • We are developing a photochemical system to destroy highly toxic organic compounds in air emissions. This is backed by data gathered through 10 years of research funded, in part, by an NSF grant.

Our Team

John Richards Ph.D. P.E.

Founder and CEO

I formed Air Control Techniques, P.C. in 1993 following more than 20 years of field experience in engineering firms and with an air pollution control equipment manufacturer.  I am a registered professional engineer in North Carolina, South Carolina, Virginia, and Georgia.


I enjoy being in the field conducting air emission tests and optimizing the performance of air pollution control systems.  I have contributed to modified testing procedures and sampling equipment for both filterable and condensable particulate matter. I am especially interested in the measurement of ambient respirable (PM4) crystalline silica and in minimizing occupational exposure to respirable crystalline silica. I helped develop the respirable crystalline silica ambient monitoring method that is now used nationally.  I am also working on the compilation of PM2.5, PM10, and hazardous air pollutant emission factors for a variety of sources.

Picture of Todd Brozell of Air Control Techniques

Todd Brozell, P.E., QSTI

Vice President

I have 34 years of field experience in air emission testing and ambient air monitoring.  I have been with Air Control Techniques, P.C. for 29 years. I am QSTI certified and a registered professional engineer in Pennsylvania, North Carolina, and Wisconsin.

My stack sampling experience includes supervision of numerous field testing projects concerning EPA Methods 5, 13B, 17, 23, 26A, 29, 201A, and 202 at power plants, fiberglass plants, wood industry plants, microelectronics plants, and Portland cement plants.  I have supervised ambient air monitoring programs at more than 20 plants concerning PM2.5, PM10, and respirable (PM4) crystalline silica using both filter-based and continuous Federal Reference Methods. I have served as the project manager for seven PM10 and PM2.5 emission factor studies at stone crushing plants in North Carolina, Tennessee and Virginia funded jointly by the EPA and the National Stone, Sand & Gravel Association to revise outdated emission factors in AP-42. These projects involved innovative techniques to accurately capture and measure emissions from non-enclosed sources.


David Goshaw, P.E., QSTI

Project Manager

I have 30 years of field experience in air emissions testing, including 25 years with Air Control Techniques, P.C.  My primary areas of expertise are FTIR analysis and CEM testing.  I am a registered professional engineer and am QSTI certified.  I served as the project leader for the Air Control Techniques, P.C. team responsible for the development of a patented photochemical control system designed to destroy dioxin-furans in industrial gas streams and was the principal developer of the state-of-the-art raw material thermal system used to analyze raw feed components for potential emissions.  As a project director with Air Control Techniques, PC, I have led complex testing and consulting projects both domestically and internationally and have conducted testing at a wide range of industrial stationary and mobile sources.

Speak with an Experienced Engineer

When you contact Air Control Techniques, an experienced engineer will evaluate your testing needs, scheduling requirements, and site-specific information. If you choose to move forward with us, we’ll prepare the test protocol for submission to the appropriate regulatory office. We can also help you evaluate permit and regulatory requirements for your testing project and negotiate with regulatory agencies.

If the proposed work is outside of our normal service area, we will be glad to recommend other testing organizations that can effectively met your needs.