1 A new furnace in a central heating system costs $2,500 to $7,500 or more. 2  If you don’t need ductwork, the cost of a new heating and cooling system can be significantly decreased. 3  In cases where new HVAC duct is required, however, you might pay $1,000 to $3,000.VAC—short for Heating, Ventilation and Air-Conditioning—refers to equipment that is used to regulate the temperature, humidity and air quality of a residential or commercial building. In this guide you’ll learn more about the components of a home HVAC system in addition to how much it costs to install one.