Halton Group - Halton in brief. Halton Group. Halton Group - Air flow management dampers. DEVap AC NREL. The following feature stories take an in-depth, behind-the-scenes look at how NREL is advancing energy efficiency and renewable energy technologies. You may subscribe to receive weekly news features by e-mail or via RSS feed . August 2012 Early attention to design makes employee parking structure a model of low energy use. July 2012.