Hybrid air-conditioning system with improved recovery evaporator and subcool condenser coils

A hybrid air-conditioning system for controlling the condition of air in a building enclosed space comprising:

• first means for passing process air through a first zone of a rotatable moisture transfer wheel and through a first zone of a rotatable heat exchange wheel to an enclosed and conditioned space, the process air also passing through a first evaporator coil;
• second means for passing regenerative air through a second zone of said heat exchange wheel, through a first condenser coil, through a second zone of said moisture transfer wheel, through a second condenser coil and a recovery evaporator coil and then to ambient space, the second zone of the moisture transfer wheel having relatively dry and wet regions;
• a first compressor having a suction side in fluid communication with a first side of the first evaporator coil and a discharge side in fluid communication with a first side of the first condenser coil;
• and
• the recovery evaporator coil having a first side in fluid communication with the suction side of the compressor, the recovery evaporator coil being positioned such that the regenerative air flow through the dry region of the second zone of the moisture transfer wheel passes through the recovery evaporator coil, and the second condenser coil being positioned such that the regenerative air flow through the wet region of the second zone of the moisture transfer wheel passes through the second condenser coil.

A hybrid air-conditioning system for controlling the condition of air in a building enclosed space comprising:

• first means for passing process air through a first zone of a rotatable moisture transfer wheel and through a first zone of a rotatable heat exchange wheel to an enclosed and conditioned space, the process air also passing through a first evaporator coil;
• second means for passing regenerative air through a second zone of said heat exchange wheel, through a first condenser coil, through a second zone of said moisture transfer wheel, through a second condenser coil and a recovery evaporator coil and then to ambient space, the second zone of the moisture transfer wheel having relatively dry and wet regions;
• a first compressor having a suction side in fluid communication with a first side of the first evaporator coil and a discharge side in fluid communication with a first side of the first condenser coil;
• a second compressor having a suction side in fluid communication with a second evaporator coil and a discharge side in fluid communication with the second condenser coil;
• and
• the recovery evaporator coil being in fluid communication with the suction side of the first compressor, the recovery evaporator coil being positioned such that the regenerative air flow through the dry region of the second zone of the moisture transfer wheel passes through the recovery evaporator coil and the second condenser coil being positioned such that the regenerative air flow through the wet region of the second zone of the moisture transfer wheel passes through the second condenser coil.

A method of operating a hybrid air-conditioning system comprising the steps of:

• rotating a moisture transfer wheel and a heat exchange wheel;
• passing a process air flow through a first zone of the moisture transfer wheel and a first zone of the heat exchange wheel;
• passing a regenerative air flow through a second zone of the heat exchange wheel and a second zone of the moisture transfer wheel, the combination of rotating the moisture transfer wheel and passing the process and regenerative air flows through the respective first and second zones of the moisture wheel creating a relatively wet region in the second zone of the moisture transfer wheel and a relatively dry region of the second zone of the moisture transfer wheel;
• operating a first compressor to compress a refrigerant to a high pressure, high temperature vapor state;
• passing the high temperature, high pressure refrigerant from the first compressor to a first condenser coil located between the second zones of the heat exchange wheel and the moisture transfer wheel to increase the temperature of the regenerative air flow and to condense the high pressure, high temperature vapor state refrigerant;
• passing the increased temperature regenerative air flow through the second zone of the moisture transfer wheel to remove moisture from the second zone of the moisture transfer wheel and to decrease the temperature of the regenerative air flow, the regenerative air flow passing through the wet region of the second zone of the moisture transfer wheel being cooled to a lower temperature than the regenerative air flow passing through the dry region;
• passing the lower temperature regenerative air flow from the wet region of the second zone of the moisture transfer wheel through a second condenser coil to subcool the condensed high pressure, high pressure refrigerant;
• passing the condensed refrigerant through a throttling device to create a low temperature, low pressure refrigerant;
• passing the low temperature, low pressure refrigerant to a recovery evaporator located downstream of the second zone of the moisture transfer wheel;
• and
• heating the low temperature, low pressure refrigerant in the recovery evaporator with the regenerative air flow from the dry region of the second zone of the moisture transfer wheel to vaporize the low temperature, low pressure refrigerant.