In the event of a fire, how effective is your ductwork insulation at stopping the spread of smoke and flames? A recently released report from NAIMA, the North American Installation Manufacturers Association, shows that not all ductwork is created equal when it comes to fire performance.  

In “Fire Performance of Duct Liners: A Product Comparison Study,” Intertek Labs conducted third-party testing on both elastomeric and fiberglass duct liners from multiple companies in order to observe how well each type performed in a fire. Liners were tested using the ASTM E84 Standard Test Method for Surface Burning Characteristics of Building Materials. Every single fiberglass liner that was tested met FSI and SDI limits, while most elastomeric liners did not.

Fiberglass is often scrutinized due to health and safety concerns, said Riley Peters, HVAC Product Manager for Johns Manville, a Berkshire Hathaway company located in Denver, Colorado.

For more than 50 years, Johns Manville has been conducting internal testing for health, safety and fire performance around fiberglass. The company currently has four fiberglass HVAC insulation products — all of which meet flame and smoke requirements.

“Given their material similarities, fiberglass in some people’s view can be lumped in with asbestos, but with that additional scrutiny over the years, fiberglass is one of the most tested products in the building materials space,” Peters said. “It's something that we take very seriously. We devote a lot of resources and capital towards product stewardship, not only with ourselves at JM, but throughout the industry to make sure that our fibers are safe for building occupants.”

Fiberglass is not cancerous, the exposure rate in a building caused by ductwork is very low, Peters said. “Our products are expected to maintain their form and insulating properties for as long as the building’s life cycle,” he adds. “Specifically our duct liner has a Permacote® facing that helps to prevent shedding as well.”

 “We’re turning a corner in the perception of fiberglass health and safety, and ensuring everybody's well-being,” he concluded.