The answer to 'what is system upgrade' is a process of improving or replacing an existing HVAC (Heating, Ventilation, and Air Conditioning) system with a newer, more efficient model. This can involve replacing the entire system, including the furnace, air conditioner, and ductwork, or just upgrading specific components like the thermostat or air filters.
A system upgrade is often recommended when an older HVAC system is no longer functioning efficiently, costing more to operate, or unable to meet the home's heating and cooling needs. Upgrading can improve energy efficiency, reduce utility bills, and provide better indoor comfort and air quality.