HVAC is Heating, Ventilation, and Air Conditioning. There are a number of systems that uses the HVAC. Obviously, the ventilation will be in place to provide for fresh air. Heating will be done through underfloor radiant heating. AC will be done through ceiling fans. The goal is to not have forced air systems. This will reduce the operation cost, and since there is no furnace, there is no filter to worry about. Obviously, there is the heating system, so it isn’t 0 maintenance, but should be more efficient than the older way of doing things.