We hired GTA Heating Co. to replace our old furnace with a new, high-efficiency model and to install a high-efficiency central a/c system. Christian was incredibly helpful from the moment I called to get a quote to final installation. He answered all our questions and provided additional information on getting an energy audit and applying for grants. He was incredibly efficient and had us up-and-running in no time. He was also really down-to-earth and straightforward, which we appreciated. We've already recommended him to some of our neighbors and will happily recommend him to others in the future. In addition, his prices were very reasonable and comparable to other quotes we received.