Zone control for HVAC system
First Claim
1. A control assembly for controlling a forced air system including a heating unit, a cooling unit, a fan, and ducting connected thereto for delivering air, which may be heated or cooled, to a plurality of zones within a structure, the control assembly comprising a plurality of zone controls, each zone control comprising:
- a thermostat situated in each of said zones including at least a heating signal output and a cooling signal output,a damper situated in an outlet of said ducting leading to each zone, and a motor coupled to each damper for changing the position of each damper, anda first relay including a set of contacts coupled to the damper motor and to a source of power sufficient to change the position of the damper, the first relay also including a coil coupled to the heating and cooling signal outputs of the thermostat in said zone so that the initiation of a heating or cooling signal by the thermostat in the selected zone affects the delivery of power to the damper motor,the control assembly also comprising;
at least one second relay including a set of contacts coupled between all the cooling signal outputs and a control unit controlling the application of power to the cooling unit, said at least one second relays also including a coil coupled to the heating signal output of all the thermostats so that initiation of a signal from a heating signal output of any of the thermostats prevents the application of power to the cooling unit.
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Accused Products
Abstract
A control assembly for a HVAC system serving a plurality of zones within a structure, having ducting including a damper situated in an outlet of the ducting leading to each zone, a biasing element biasing the damper in a normally open position, and a motor coupled to each damper for closing each damper. A standard manual or automatic change-over thermostat is situated in each of the zones which includes at least a heating signal output and a cooling signal output. The control assembly formed by a collection of diodes and relays includes a pair of relays having a set of normally open contacts coupled between the damper motors and a source of power, one of the pair of relays having a coil coupled to the heating signal outputs of all of the thermostats and another of the pair of relays having a coil coupled to the cooling signal outputs of all of the thermostats so that, upon initiation of a heating or cooling signal from any of the thermostats, power is applied to the motor coupled to each damper for closing each damper. The control assembly includes individual zone controls each of which are formed by a collection of diodes and relays including a first additional relay which has a set of normally closed contacts coupled between the damper motor in the zone and the source of power, and a coil coupled to the heating and cooling signal outputs of the thermostat in the zone so that the initiation of a heating or cooling signal by the zone thermostat opens the normally closed contacts of the first additional relay thus preventing power from being applied to the damper motor leading to the zone thereby permitting the damper to remain open under influence of the biasing element. A second additional relay has a set of normally closed contacts coupled between the cooling signal output of all the thermostats and a control unit controlling the application of power to the cooling unit, and a coil coupled to the heating signal output of all the thermostats so that initiation of a signal from a heating signal output of any of the thermostats prevents the application of power to the cooling unit thus achieving automatic change-over between heating and cooling.
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Citations
24 Claims
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1. A control assembly for controlling a forced air system including a heating unit, a cooling unit, a fan, and ducting connected thereto for delivering air, which may be heated or cooled, to a plurality of zones within a structure, the control assembly comprising a plurality of zone controls, each zone control comprising:
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a thermostat situated in each of said zones including at least a heating signal output and a cooling signal output, a damper situated in an outlet of said ducting leading to each zone, and a motor coupled to each damper for changing the position of each damper, and a first relay including a set of contacts coupled to the damper motor and to a source of power sufficient to change the position of the damper, the first relay also including a coil coupled to the heating and cooling signal outputs of the thermostat in said zone so that the initiation of a heating or cooling signal by the thermostat in the selected zone affects the delivery of power to the damper motor, the control assembly also comprising; at least one second relay including a set of contacts coupled between all the cooling signal outputs and a control unit controlling the application of power to the cooling unit, said at least one second relays also including a coil coupled to the heating signal output of all the thermostats so that initiation of a signal from a heating signal output of any of the thermostats prevents the application of power to the cooling unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A control assembly for controlling a forced air system including a heating unit, a cooling unit, a fan, and ducting connected thereto for delivering air, which may be heated or cooled, to a plurality of zones within a structure, the control assembly comprising a plurality of zone controls, each zone control comprising:
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a thermostat situated in each of said zones including at least a heating signal output and a cooling signal output, a damper situated in an outlet of said ducting leading to each zone, a biasing element biasing the damper toward an open position permitting air to flow from the ducting into each zone, and a motor coupled to each damper for closing each damper, and a first relay including a set of normally closed contacts coupled to the damper motor and to a source of power sufficient to close the damper, the first relay also including a coil coupled to the heating and cooling signal outputs of the thermostat in said zone so that the initiation of a heating or cooling signal by the thermostat in the selected zone opens the normally closed contacts of the first relay removing power from the motor coupled to the damper leading to the selected zone thereby permitting the damper to open under influence of the biasing element, the control assembly also comprising; at least one second relay including a set of normally closed contacts coupled between all the signal outputs of a first type selected from the group consisting of heating and cooling and a control unit controlling the application of power to the temperature modifying unit of the same type, the at least one second relay also including a coil coupled to the signal output of the opposite type of all the thermostats so that initiation of a signal from a selected one of the heating or cooling signal outputs of any of the thermostats prevents the application of power to the temperature modifying unit of the opposite type. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A control assembly for controlling a forced air system including a heating unit, a cooling unit, a fan, and ducting connected thereto for delivering air, which may be heated or cooled, to a plurality of zones within a structure, the control assembly comprising a plurality of zone controls, each zone control comprising:
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a damper situated in an outlet of said ducting leading to each zone, a biasing element biasing the damper in a normally open position permitting air to flow from the ducting into each zone, and a motor coupled to each damper for closing each damper, a thermostat situated in each of said zones including at least a heating signal output and a cooling signal output, the control assembly also comprising; a pair of relays including a set of normally open contacts coupled between said motors coupled to each damper and a source of power sufficient to close the dampers, one of the pair of relays having a coil coupled to the heating signal outputs of all of the thermostats and another of the pair of relays having a coil coupled to the cooling signal outputs of all of the thermostats so that, upon initiation of a heating or cooling signal from any of the thermostats, power is applied the motor coupled to each damper for closing each damper, a first additional relay means including sets of normally closed contacts, each set of normally closed contacts being coupled between a damper motor in one of the zones and said source of power, the first additional relay means also including a coil coupled to the heating and cooling signal outputs of the thermostat in said one of the zones so that the initiation of a heating or cooling signal by the thermostat in said one of the zones opens the normally closed contacts of the first additional relay means thus preventing power controlled by said pair of relays from being applied to the motor coupled to the damper leading to said one of the zones thereby permitting the damper to remain open under influence of the biasing element, and at least one second additional relay including a set of normally closed contacts coupled between all the signal outputs of a first type selected from the group consisting of heating and cooling and a control unit controlling the application of power to the temperature modifying unit of the same type, the at least one second additional relay also including a coil coupled to the signal output of a second type of all the thermostats so that initiation of a signal from a selected one of the heating or cooling signal outputs of any of the thermostats prevents the application of power to the temperature modifying unit of the second type. - View Dependent Claims (21, 22, 23, 24)
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Specification