Open loop WaterFurnace Envision system. Again with the Intellizone multi-zone control. All the Envision systems feature R410A earth friendly refrigerant, variable speed blower motors, and 2-stage compressor operation. The system is extremely quiet and makes about as much noise as a standard refrigerator. As with all open loop systems, we install components in the plumbing package to ensure any water noise is kept to a minimum. This is significant for anyone considering an open loop. With well pressures at 60psi, the water noise can be much louder than the heat pump if not installed correctly.