Heating, ventilation, and air conditioning system and method

A method for operating an air conditioning system, in a building having pre-existing central air conditioning, wherein the air conditioning system comprises one or more thermostats, configured to sense a temperature at a location of the thermostat in a conditioned space in a building, and to sense a temperature in a basement of the building;

• a computing or wiring based control system;
• a main return duct;
• a basement supply duct and a basement return duct, each connected on one end to said main return duct, and each opening on another end to said basement;
• and dampers for controlling air flow through said main return duct, said basement supply duct, and said basement return duct,
• wherein the method comprises the steps of:
• if the temperature in the basement is less than a predetermined threshold cooler than the temperature of the conditioned space, entering a charging mode, comprising:
• activating an evaporator and an air handler, and circulating air through said main return duct, said air handler and said evaporator;
• and
• if the temperature in the basement is equal to or greater than said predetermined threshold cooler than the temperature of the conditioned space, entering a cooling mode, comprising:
• deactivating the evaporator, activating the air handler, or allowing the air handler to remain active, and circulating air through said main return vent, said basement supply duct, said basement return duct and said air handler.

A method for operating an air conditioning system, in a building with pre-existing forced air heating, and without pre-existing central air conditioning, wherein the system comprises one or more thermostats, configured to sense a temperature at a location of the thermostat in a conditioned space in a building, and to sense a temperature in a basement of the building;

• a computing or wiring based control system;
• a main return duct;
• a basement supply duct and a basement return duct, each connected on one end to said main return duct, and each opening on another end to said basement;
• and dampers for controlling air flow through said main return duct, said basement supply duct, and said basement return duct,
• wherein the method comprises the steps of:
• if the temperature in the conditioned space is above a desired temperature, measuring the temperature in the basement;
• if the temperature in the basement is equal to or greater than a predetermined threshold cooler than the temperature of the conditioned space, entering a cooling mode, comprising:
• activating an air handler, and circulating air through said main return vent, said basement supply duct, said basement return duct and said air handler;
• and
• if the temperature in the basement is less than a predetermined threshold cooler than the temperature of the conditioned space, entering a charging mode, comprising:
• shutting off the system and allowing the basement to disperse heat into the earth.

An air conditioning system having a computing or wiring based control system, comprising:

• one or more thermostats, configured to sense a temperature at a location of the thermostat in a building, and to sense a temperature in a basement of the building;
• a main return duct;
• a heat exchanger formed within, or inline with, said main return duct;
• and
• a blower or fan, whereby said blower or fan is configured to move air from the basement over said heat exchanger, while air is passing through said main return duct, to allow heat transfer between the basement air and duct air without mixing of said basement air and said duct air.