1. Save energy. A lot can happen to your heating and cooling units over time that prevents them from performing efficiently. When a technician inspects your units, he or she will ensure that they are running as smoothly and efficiently as possible, which will cut down on the amount of energy they use. 2. Avoid unnecessary repairs. When you have HVAC preventive maintenance twice a year, you can stop problems to your units before they start. This will minimize the amount of times you have to call a contractor to come to your home and make repairs.