Economizer hvac and control system

Abstract

An HVAC and control system with an economizer mode and continuous damper position verification. Three dampers are provided with a control module that accepts inputs from multiple temperature sensors and a user, and which monitors and reports the position and off-normal operation of multiple dampers.

What is claimed is: 
     
         1 . An HVAC and control system for economizer operation, the HVAC system having a power source, a circulation fan, a cooling unit, and a network of air delivery ducts for cooling a conditioned space, the HVAC and control system comprising:
 an outside air intake duct and a first damper movable between an open and a closed position, with said first damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and signaling a closed or open damper position;   an outside air temperature sensor for sensing the temperature of outside air;   a control module mounted in said conditioned space with a damper error indicator comprising at least one visual indicator of damper position error, with said control module operationally connected to said power source, said circulation fan and cooling unit, to said first damper, and to said outside air temperature sensor;   an economizer mode in which said first damper is opened to allow outside air to be pulled into said HVAC system when said economizer mode is selected, with said selection based on a preselected temperature of outside air or by manual control selection; and   a non-economizer mode in which said first damper is closed to prevent outside air from entering said HVAC system when said economizer mode is not selected, with said non-economizer mode selected by outside air temperature being above said preselected temperature or by manual selection.   
     
     
         2 . The HVAC and control system of  claim 1  which further comprises an isolation damper positioned in a return air duct, with said isolation damper coordinated with said first damper to operate in an opposite manner as said first damper, with said isolation damper closed when said first damper is open, and open when said first damper is closed, thereby using exclusively outside air for cooling when outside air is at temperature is at or below the user setting, with said isolation damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and continuously signaling a closed or open damper position. 
     
     
         3 . The control system of  claim 2  which further comprises a relief damper positioned in said return air duct between said conditioned space and said isolation damper, with said relief damper coordinated with said isolation damper to operate in an opposite manner as said isolation damper, with said relief damper closed when said isolation damper is open, and open said isolation damper is closed, thereby routing air from said conditioned space out of said duct system when said system is using outside air for cooling, with said relief damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and continuously signaling a closed or open damper position. 
     
     
         4 . The HVAC and control system for an economizer system of  claim 1  in which said damper position sensors send a continuous feedback of proper damper position to said control module, with said control module displaying a continuous indicator of proper damper position. 
     
     
         5 . The HVAC and control system for an economizer system of  claim 1  which further comprises an economizer failsafe signal which is activated when an off normal damper position is detected, preventing operation with improperly positioned dampers, and in one embodiment configured to close said first damper. 
     
     
         6 . The HVAC and control system for an economizer system of  claim 1  in which said outside air temperature sensor is configured to activate said economizer mode, by a comparison between said outside air temperature and a user setting. 
     
     
         7 . The HVAC and control system for an economizer system of  claim 1  which further comprises a damper cable with a first end and a second end, with said end of said damper cable comprising a plurality of conductors with said damper cable terminated on both ends with geometrically coded connectors, with said control module comprising a corresponding geometrically coded connector for engagement with said first end of said damper cable, and with said second end of said damper cable configured to engage a corresponding geometrically coded connection at said damper(s) with said geometrically coded connectors shaped to prevent misalignments and to allow for error free assembly. 
     
     
         8 . The HVAC and control system for an economizer system of  claim 1  which further comprises an isolation damper and a third damper, the isolation damper positioned in a duct between said conditioned space and said outside air intake duct, and said third damper positioned between said conditioned space and said isolation damper, to allow the release of air from the ducting system, with said isolation damper closed and said third damper open in said economizer mode, and with said isolation damper open and said third damper closed in said non-economizer mode. 
     
     
         9 . An HVAC and control system for an economizer system for use with an HVAC system, the HVAC system having a power source, a circulation fan, a cooling unit, and a network of air delivery ducts for cooling a conditioned space, the control system comprising:
 an outside air intake duct and a first damper movable between an open and a closed position, with said first damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and signaling a closed or open damper position;   an isolation damper positioned between said conditioned space and said outside air intake duct, with said isolation damper closed in said economizer mode and with said isolation damper open in said non-economizer mode, with said isolation damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and signaling a closed or open damper position;   and a third damper positioned between said conditioned space and said isolation damper, to allow the release of pressurized air from the conditioned space said third damper configured to release overpressure air in said economizer mode, and with said third damper closed in said non-economizer mode, with said third damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and signaling a closed or open damper position;   in which each of said damper position sensors send a continuous feedback of proper damper position to said control module, with two damper position signals per damper;   an outside air temperature sensor for sensing the temperature of outside air;   a control module mounted in said conditioned space with a damper error indicator comprising at least one visual indicator of damper position error, with said control module operationally connected to said power source, said circulation fan and cooling unit, to said first damper by a damper cable, and to said outside air temperature sensor, and with said control module displaying a continuous indicator of proper damper position indicating all dampers are in proper position;   said damper cable with a first end and a second end, with said damper cable comprising a plurality of conductors with said damper cable terminated on both ends with geometrically coded connectors, with said control module comprising a corresponding geometrically coded connector for engagement with said first end of said damper cable, and with said second end of said damper cable configured to engage a corresponding geometrically coded connection at said first, second, and third damper with said geometrically coded connectors shaped to prevent misalignments and to allow for quick and error free assembly;   an economizer mode in which said first damper is opened to allow outside air to be pulled into said HVAC system when said economizer mode is selected, with said selection based on a preselected temperature of outside air or by manual control selection; and   a non-economizer mode in which said first damper is closed to prevent outside air from entering said HVAC system when said economizer mode is not selected, with said non-economizer mode selected by outside air temperature being above said preselected temperature or by manual selection.   
     
     
         10 . The HVAC and control system for an economizer system of  claim 9  in which said two damper position signals from each of three dampers are sent to a damper position verification unit, which sends a single damper position signal to said control module. 
     
     
         11 . The HVAC and control system for an economizer system of  claim 9  which further comprises an economizer failsafe signal which is activated when an off normal damper position is detected, with said economizer failsafe signal configured to prevent improper operation, and in one embodiment to close said first damper. 
     
     
         12 . The HVAC and control system for an economizer system of  claim 9  in which said outside air temperature sensor is configured to activate said economizer mode, by a comparison between said outside air temperature and a user setting. 
     
     
         13 . The HVAC and control system of  claim 9  which further comprises a readiness status signal, which is calculated and displayed on said control module, with said readiness status calculated based on outside temperature being sufficient to provide space cooling, and safety conditions determined and configured by system installer being satisfied. 
     
     
         14 . The HVAC and control system of  claim 9  which further comprises a sensor monitor for monitoring of temperature sensors and reporting of temperature sensor malfunction, with errors displayed on said control display. 
     
     
         15 . The HVAC and control system of  claim 9  which further comprises a calculator of system statistics and a display of system usage and economic benefit, comprising run time and percentage of cooling accomplished by input of outside air. 
     
     
         16 . An HVAC and control system for an economizer system for use with an HVAC system, the HVAC system having a power source, a circulation fan, a cooling unit, and a network of air delivery ducts for cooling a conditioned space, the control system comprising:
 an outside air intake duct and a first damper movable between an open and a closed position, with said first damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and signaling a closed or open damper position;   an isolation damper positioned between said conditioned space and said outside air intake duct, with said isolation damper closed in said economizer mode and with said isolation damper open in said non-economizer mode, with said isolation damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and signaling a closed or open damper position;   and a third damper positioned between said conditioned space and said isolation damper, to allow the release of pressurized air from the conditioned space said third damper configured to release overpressure air in said economizer mode, and with said third damper closed in said non-economizer mode, with said third damper comprising a damper open position sensor and a damper closed position sensor, with said damper position sensors sensing and signaling a closed or open damper position;   in which each of said damper position sensors send a continuous feedback of proper damper position to said control module, with two damper position signals per damper, with said two damper position signals from each of three dampers are sent to a damper position verification unit, which sends a single damper position signal to said control module;   an outside air temperature sensor for sensing the temperature of outside air;   a control module mounted in said conditioned space with a damper error indicator comprising at least one visual indicator of damper position error, with said control module operationally connected to said power source, said circulation fan and cooling unit, to said first damper by a damper cable, and to said outside air temperature sensor, and with said control module displaying a continuous indicator of proper damper position indicating all dampers are in proper position;   said damper cable with a first end and a second end, with said damper cable comprising a plurality of conductors with said damper cable terminated on both ends with geometrically coded connectors, with said control module comprising a corresponding geometrically coded connector for engagement with said first end of said damper cable, and with said second end of said damper cable configured to engage a corresponding geometrically coded connection at said first, second, and third damper with said geometrically coded connectors shaped to prevent misalignments and to allow for quick and error free assembly;   an economizer mode in which said first damper is opened to allow outside air to be pulled into said HVAC system when said economizer mode is selected, with said selection based on a preselected temperature of outside air or by manual control selection; and   a non-economizer mode in which said first damper is closed to prevent outside air from entering said HVAC system when said economizer mode is not selected, with said non-economizer mode selected by outside air temperature being above said preselected temperature or by manual selection.