Zak is very professional and highly knowledgeable in his expertise of air quality for my HVAC system Custom Experts installed for me about 2 years ago. I am asthmatic and am looking into added air quality options for my system, especially now that Fall and Winter are on their way along with the crud that comes with them. Zak explained everything to me so I will be able to make a wise decision. By the way, all of the techs that have helped have been fantastic as well. Colby is also fantastic! Happy customer here.... :-)