Excerpt from the eVent Facebook page: https://www.facebook.com/eventfabrics1/posts/964691750309807
The membranes used in eVent fabrics are fully manufactured at their plant in Lee's Summit, Missouri, USA–essentially transforming a powder into a high-tech film that is thin, porous and, in the case of waterproof products, performs the neat trick of being super-breathable and weatherproof.
A by-product of creating these membranes are heat and gasses that contain volatile organic compounds (VOCs), which can be destroyed by high heat so that clean emissions are released into the environment.
This year, eVent completed installation of a closed-loop regenerative thermal oxidizer, which ensures their emissions are clean and which also recaptures energy through the use of large ceramic heat sinks. How does it work? The by-product gas enters the system at 180° Fahrenheit (82° C) into the first 'hot' tank, where it picks up heat to raise its temperature to 1250° F (677° C). More heat is added to increase the temperate to 1500° F (815° C), which oxidizes and wipes out the harmful volatiles in the gas. But before the now-clean gas is exhausted to the outside, the amassed heat is transferred to a second 'cold' tank where it is cooled to 230° F (110° C). Every few minutes large valves change the direction of the flow between the two tanks, effectively recycling the energy required to cleanse the gasses . Cool technology, clean air!