Abstract: Configuration of flow paths for the output (e.g., chilled or heated air) of an HVAC system is described. In one embodiment, a demand response message can be received from a resource provider requesting that the HVAC system increase or decrease consumption of the resource. If the request is satisfied, then the output from the HVAC device will be increased or decreased resulting in potential discomfort for occupants. This output, however, rather than being distributed in a uniform manner, can instead be distributed, via ventilation elements of the HVAC system in a non-uniform way according to the flow paths. The flow paths can be determined to direct sufficient output to high priority zones in order to, e.g., satisfy a comfort level in the high priority zones.

Abstract: Systems and methods for self-learning fault detection and diagnosis in an HVAC system include a server identifying a fault and one or more predicted causes of the fault based on measurements of operational parameters received from sensors associated with the HVAC system. The operational parameters are compared to evaluation criteria, such as predetermined thresholds, to identify a potential fault. Parameters may be weighted, and optionally scaled to a standardized range to facilitate the diagnosis of HVAC systems of disparate configurations and capacities. Evaluation criteria for each fault are periodically analyzed in view of operational parameter history to identify new criteria having a lower probability of misdiagnosis. Fault detection criteria which are determined to have an unacceptable error rate may be deactivated or flagged for review.

Abstract: Configuration of flow paths for the output (e.g., chilled or heated air) of an HVAC system is described. In one embodiment, a demand response message can be received from a resource provider requesting that the HVAC system increase or decrease consumption of the resource. If the request is satisfied, then the output from the HVAC device will be increased or decreased resulting in potential discomfort for occupants. This output, however, rather than being distributed in a uniform manner, can instead be distributed, via ventilation elements of the HVAC system in a non-uniform way according to the flow paths. The flow paths can be determined to direct sufficient output to high priority zones in order to, e.g., satisfy a comfort level in the high priority zones.

Abstract: Systems and methods for fault detection and diagnosis (FDD) in a heating, ventilation and air conditioning (HVAC) system include a server identifying a fault and one or more predicted causes of the fault based on measurements of operational parameters from the HVAC system. The server also receives and utilizes information associated with the reported fault from service technicians who service the HVAC to correct the reported fault condition. The information includes details of the corrective measures successfully implemented by the technicians to correct the fault, and a determination of whether the server correctly identified the actual fault. The information is implemented by the server to improve the accuracy of the FDD algorithms based on measured parameters of the HVAC system.

Abstract: A fault detection module and related methods of prognostic fault detection for an HVAC system are disclosed. Baseline operating parameters of an HVAC system operating in a known balanced state are collected during a calibration period. A set of coefficients for an enthalpy model are generated from the collected baseline parameters to define the balanced operation of the HVAC system. During normal operating times, runtime operating parameters of the HVAC system are collected. The expected high-side and low-side enthalpies are computed using the enthalpy model, and compared to actual high-side and low-side enthalpies. The relationships between expected and actual enthalpies are utilized to determine whether a potential or actual fault condition exists, and optionally, the nature of the fault. A fault message indicating the fault is transmitted to one or more recipient devices.

Abstract: Systems and methods for self-learning fault detection and diagnosis in an HVAC system include a server identifying a fault and one or more predicted causes of the fault based on measurements of operational parameters received from sensors associated with the HVAC system. The operational parameters are compared to evaluation criteria, such as predetermined thresholds, to identify a potential fault. Parameters may be weighted, and optionally scaled to a standardized range to facilitate the diagnosis of HVAC systems of disparate configurations and capacities. Evaluation criteria for each fault are periodically analyzed in view of operational parameter history to identify new criteria having a lower probability of misdiagnosis. Fault detection criteria which are determined to have an unacceptable error rate may be deactivated or flagged for review.

Abstract: A system and a method are provided for monitoring a condition and selectively executing a certification defrost algorithm for a heating, ventilation, and air conditioning (HVAC) system in response to the status of the monitored condition. A system and a method are provided for selectively operating a certification defrost algorithm in parallel to a field defrost algorithm. A system and a method are also provided for causing a controller to execute a first algorithm and for causing the controller to selectively execute a second algorithm while also executing the first algorithm where each of the first algorithm and the second algorithm are configured to selectively cause the HVAC system to operate in a defrost mode.

Abstract: A method of charging an HVAC system by determining a relationship between a liquid line temperature of the HVAC system, a suction line pressure of the HVAC system, and an ambient outdoor temperature of the HVAC system. A method of charging an HVAC system by adjusting a mass of refrigerant in the HVAC system to approach a target minimum liquid line temperature. A method of charging an HVAC system by testing the HVAC system according to at least three sets of test parameters, two of the three sets of test parameters comprising testing the HVAC system at substantially a same outdoor ambient temperature and at least one of the remaining set of test parameters comprising testing the HVAC system at a different outdoor ambient temperature.

Abstract: A system and a method are provided for monitoring a condition and selectively executing a certification defrost algorithm for a heating, ventilation, and air conditioning (HVAC) system in response to the status of the monitored condition. A system and a method are provided for selectively operating a certification defrost algorithm in parallel to a field defrost algorithm. A system and a method are also provided for causing a controller to execute a first algorithm and for causing the controller to selectively execute a second algorithm while also executing the first algorithm where each of the first algorithm and the second algorithm are configured to selectively cause the HVAC system to operate in a defrost mode.