The HVAC system for all 25,000 square feet under roof is controlled by a computer system designed by Johnson Controls. It is connected to two 25-ton air conditioning central chiller units and utilizes a “4 pipe” system which constantly circulates hot and cold water throughout the home. There are 22 different zones for heating and cooling and the system maintains the temperature at the desired level with no more than a half-degree difference. In order to maintain continuous service under even the most unusual conditions, the HVAC system was designed with built-in redundancy. It is a duplex, three-phase power, commercial grade system that delivers more power at greater efficiency than virtually any residential system. The massive chiller units for the air conditioning system have been placed on special isolation pads in a poured concrete vault. Rubber shocks provide additional sound insulation. It is surprisingly quiet and dramatically responsive.