The best way to determine what type of HVAC system you have is to look at the model number and serial number of the unit. This information can usually be found on the manufacturer’s label, which is typically located on the side or back of the unit. You can then use this information to look up the system type and model online. Additionally, you can contact the manufacturer directly to inquire about the system type and model. If you are unable to locate the model number and serial number, you may need to consult a professional HVAC technician to inspect the system and provide you with the necessary information.