Adaptive forced warm air furnace using analog temperature and pressure sensors

A method for regulating circulation blower setpoints to maintain constant pressure in a forced air zoned heating system the forced air furnace having return ducts, a heat exchanger, warm air ducts, a circulation blower, and a burner, comprising the steps of:

• receiving a heating request from an external controller;
• energizing the burner in the furnace to heat the heat exchanger;
• energizing the circulation blower;
• sensing the pressure in the heat exchanger;
• regulating the circulation blower at a circulation setpoint to maintain a constant pressure in the heat exchanger;
• measuring the time required to satisfy said heating request;
• increasing the circulation blower setpoint to maintain a second constant pressure if said time required to satisfy said heating request increases;
• decreasing the circulation blower setpoint to maintain a third constant pressure if said time required to satisfy said heating request decreases;
• and
• de-energizing the burner and the circulation blower when said heating request is satisfied.

A method for regulating circulation blower setpoints to maintain constant pressure in a forced air zoned heating system the forced air furnace having return ducts, a heat exchanger, warm air ducts, a circulation blower, and a burner, comprising the steps of:

• receiving a heating request from an external controller;
• energizing the burner in the furnace to heat the heat exchanger;
• energizing the circulation blower;
• sensing the pressure in the heat exchanger;
• regulating the circulation blower at a circulation setpoint to maintain a constant pressure in the heat exchanger;
• measuring cycle "on " time of said furnace;
• increasing said circulation blower setpoint to maintain a second constant pressure if said "on " time increases;
• decreasing said circulation blower setpoint to maintain a third constant pressure if said "on " time decreases;
• de-energizing the burner and the circulation blower when said heating request is satisfied.

A furnace control for a forced air control heating system for multi-zone heating, the forced air furnace having return ducts, a heat exchanger, warm air ducts, a circulation blower, and a burner, the forced air furnace receiving the heating requests for external control means, wherein said furnace provides heat to at least one zone to be heated, the burner heating the heat exchanger, the circulation blower forcing air from the return ducts through the heat exchanger and out the warm air duct to the zone to be heated, said furnace control comprising:

• temperature sensor for sensing the temperature of the heat exchanger;
• regulation means for regulating the burner, said temperature sensor providing a signal representative of the air temperature in the heat exchanger to said regulation means, said regulation means regulating the burner such that said heat exchanger is held to a constant temperature after reaching a preset temperature during the external controller request for heat;
• a pressure sensor for measuring the pressure in the heat exchanger;
• a controller for controlling the circulation blower, said pressure sensing means providing a signal representative of said pressure in the heat exchanger to said controller, said controller regulating the circulation blower wherein said pressure in the heat exchanger is held constant;
• and
• wherein said controller further comprises timing means, wherein said furnace satisfies said request for heat in a period of time, wherein said timing means times said period of time, said controller increasing said pressure if said period of time is greater than a first predetermined time.