My home was built in 1995. I bought it in 2003 and replaced the original gas pack once. By 2016 the entire subfloor duct system had been destroyed by humidity. One of the owners, Art Harman, came by to analyze my needs and made a very sensible recommendation. I took his advice to replace an entirely worn out and slightly undersized system. I could not be more pleased with the product, installation and customer service. Thank you, Comfort First!