Oklahoma City Commercial Rooftop HVAC Systems Gordon's Service Experts Heating & Air Conditioning in Oklahoma City gives you choice in commercial rooftop HVAC products and services. Lennox® packaged rooftop commercial HVAC systems are among the most innovative products you can find today, including the new solar powered SunSource® System for Energence® rooftop HVAC systems. Bringing industry-leading technology and efficiency with expert installation and service means you receive long-lasting, sustainable systems created to provide exceptional comfort and indoor air quality (IAQ) in your commercial offices. In addition, three of our four units – Energence, Strategos® and Landmark® - are ENERGY STAR® certified, which will help reduce your energy expenses, leading to a lower total cost of ownership. Call 405-432-2197 to learn more.