Abstract: A system and method are provided for extending a communication protocol by constructing a top level message, constructing a first level extension message, and embedding the first level extension message in a data component of the top level message. Also, a system and method are provided for extending a communication protocol by receiving a top level message from a communication medium, determining whether a first level extension message is included within the top level message, and extracting the first level extension message from the top level message. Further, a system and method are provided for extending a communication protocol by using a processor to embed a first level extension packet within a top level packet. At least one of the top level packet and the first level extension packet include a message for use in an HVAC system.

Abstract: Heating, ventilating and air conditioning (HVAC) equipment units are provided with controllers which may be interconnected to a third or common controller, such as a communicating thermostat, and provide information in a process to determine if two or more of such air conditioning units may be operated as twinned units. Information is transmitted over a data bus between the controllers for the respective air conditioning units and the common controller to determine if the air conditioning units are the same type, of a same family and of essentially the same capacity before permitting twinned operation. If one of the air conditioning units is not twinnable, an alarm signal is generated to prevent operation of the air conditioning units in a multiple-unit configuration.

Abstract: A user interface for a control system for an air conditioning apparatus includes a visual display and keys for scrolling menu items and entering commands to the control system. The interface is mounted in the apparatus cabinet and on a rotatable bracket to orient the interface for ease of reading the display and actuating the respective keys.

Abstract: A system and method are provided for extending a communication protocol by constructing a top level message, constructing a first level extension message, and embedding the first level extension message in a data component of the top level message. Also, a system and method are provided for extending a communication protocol by receiving a top level message from a communication medium, determining whether a first level extension message is included within the top level message, and extracting the first level extension message from the top level message. Further, a system and method are provided for extending a communication protocol by using a processor to embed a first level extension packet within a top level packet. At least one of the top level packet and the first level extension packet include a message for use in an HVAC system.

Abstract: An air conditioning apparatus including a heater or furnace includes a controller for receiving control signals from a thermostat and from a user interface for initiating a contingency mode of operation when a signal from the thermostat is not available. The user interface includes a visual display and multiple keys for entering the contingency mode which includes selecting a capacity of heat output of the apparatus and a duty cycle. The user interface may be disposed in the apparatus cabinet and connected directly to a microprocessor based controller for the apparatus. The contingency mode is automatically aborted if a fault signal is received by the controller, a signal is received from a thermostat or power to the apparatus is interrupted.

Abstract: A user interface for a control system for an air conditioning apparatus includes a visual display and keys for scrolling menu items and entering commands to the control system. The interface is mounted in the apparatus cabinet and on a rotatable bracket to orient the interface for ease of reading the display and actuating the respective keys.

Abstract: An air conditioning apparatus including a heater or furnace includes a controller for receiving control signals from a thermostat and from a user interface for initiating a contingency mode of operation when a signal from the thermostat is not available. The user interface includes a visual display and multiple keys for entering the contingency mode which includes selecting a capacity of heat output of the apparatus and a duty cycle. The user interface may be disposed in the apparatus cabinet and connected directly to a microprocessor based controller for the apparatus. The contingency mode is automatically aborted if a fault signal is received by the controller, a signal is received from a thermostat or power to the apparatus is interrupted.

Abstract: Heating, ventilating and air conditioning (HVAC) equipment units are provided with controllers which may be interconnected to a third or common controller, such as a communicating thermostat, and provide information in a process to determine if two or more of such air conditioning units may be operated as twinned units. Information is transmitted over a data bus between the controllers for the respective air conditioning units and the common controller to determine if the air conditioning units are the same type, of a same family and of essentially the same capacity before permitting twinned operation. If one of the air conditioning units is not twinnable, an alarm signal is generated to prevent operation of the air conditioning units in a multiple-unit configuration.

Abstract: An intense field dielectric air filtration system associated with an air conditioning unit includes a microprocessor based control system which may be connected to the thermostat of the air conditioning unit to energize the air filtration system in response to a call for heat or cooling signal at the thermostat or startup of the fan motor for the air conditioning unit. The control system includes a power supply for the air filtration system together with voltage and current monitoring circuits for detecting a fault condition. Filtration system on/off and timing function reset switches are connected to the microprocessor and visual displays, including a multicolored LED bargraph display, are controlled by the microprocessor to indicate voltage potential applied to the air filtration system, a fault condition or a test mode.