Direct-fired heaters are popular with manufacturers because they quickly warm large areas in plants, while taking up limited floor space. Similar to a gas grill, these heaters provide heat by forcing air through a natural gas flame. Their direct heat transfer is nearly 100 percent fuel and combustion efficient, and the equipment can even be equipped with cooling and energy recovery functions.

Sigma Thermal Inc. (STI) has engineered and manufactured direct-fired heaters for customers worldwide since 2007. The company also produces thermal fluid and biomass-fired energy systems, as well as indirect-process bath heaters and electric-process heaters. In 2018, STI merged with Flaretec, which designs, builds and services direct- and indirect-fired heaters.

One year earlier, STI looked into ways to optimize energy usage at its large fabricating facility in Marietta, GA. The company decided to have renewable-energy specialist Renewvia Energy install a 100-kilowatt solar panel array on the facility roof in the fall of 2017.

“We spend quite a bit of time making sure that our technology works efficiently, effectively and with the lowest possible emissions levels to maximize every ounce of our customers’ energy,” notes Jeff Ackel, CEO and principal of STI. “By install[ing] solar technology at our facility, we start the process—and the impact—from the ground up.”

The solar panel array generates up to 144,000 kilowatt-hours per year, which is enough energy to provide nearly 100 percent of the manufacturer’s electricity needs during lower-consumption periods. This level of generated energy is also enough to supplement roughly half of the manufacturer’s electricity needs during peak consumption times.

According to Ackel, the solar panel array will reduce STI’s carbon footprint by 106 metric tons annually. The company expects to see a complete return on the solar investment sometime in 2020.

Encompassing 40,000 square feet, the STI fabricating facility has a 36-foot under hook height and two fabrication bays. One bay has a 50-ton lifting capacity, and the other has a 60-ton capacity.

The facility is located on a 10-acre campus, which also includes 15,000 square feet of engineering offices; 40,000 square feet for outdoor work, product lay-down and storage space; a 5,000-square-foot warehouse; and a 1,500-square-foot, UL-listed panel shop.

All of STI’s direct-fired heaters incorporate advanced emission-limiting technologies to help their customers meet the most stringent environmental regulations. In addition, the company’s biomass-fired energy and waste-heat recovery systems help manufacturers reduce their renewable-energy consumption.

Renewvia has designed and installed rooftop, canopy and ground-mounted solar arrays for manufacturers in a wide range of industries since 2008. Adhesive and coating manufacturer Worthen Industries Inc., for example, has had solar panels installed on the roofs of its Nashua, NH, and Clinton, MA, plants.

Last December, Renewvia completed the largest commercial distributed rooftop solar array in Alabama at SteelFab Inc.’s Roanoke steel
fabrication plant. The system there includes 2,296 photovoltaic panels providing 746 kilowatts of power.

Other installations of note are the North Georgia Medical Center in Rome, GA; the IDI distribution center in Elizabeth, NJ; Lake View Fisheries in Kenya; and Blue Water Homes in Gualo Rai, Saipan.

For more information on solar panel array systems, call 404-856-4380 or visit