An HVAC system is provided. Embodiments of the present disclosure generally relate to heat exchangers having tubing with a reduced diameter compared to traditional systems. In one embodiment, a ducted HVAC system comprises an outdoor heat exchanger with tubing that has an outer diameter of eight millimeters (8 mm) or less and an indoor heat exchanger with tubing that has an outer diameter of nine millimeters (9 mm) or less. Additional systems, devices, and methods are also disclosed.