a.d. winston Service, Inc. HVAC professionals boast a cumulative total of more than 150 years of experience. Since its founding in 1990, the company has established a long list of satisfied customers who value the outstanding service we provide.Since 1990, a.d. winston Service, Inc. has been Maintaining and Servicing HVAC systems and we provide our customers with a superior level of service due to the use of our computer planned preventive maintenance tasking. This ensures that the preventive maintenance is performed at the correct intervals to keep your systems operating efficiently, while providing your facility with optimum comfort conditions. These maintenance programs are customized to meet any and all customers' requirements, both mechanical and financial.