If you want to install an HVAC system, how to choose the right HVAC contractor in your own city. The 4 tips that you can follow to choose the best HVAC service: Number-1 Read Reviews About the HVAC Contractor, Number-2 Look at the Professional Aspects of the HVAC Contractor, Number-3 Do Homework and Create a Short List, Number-4 Ask Your Friends and Families.