A system and method for analyzing an HVAC/R system includes a receiver for receiving signals from sensors, a memory for storing a pressure-enthalpy relationship for refrigerant of the HVAC/R system, a processor in communication with the receiver and the memory, the processor configured to determine a first energy transfer value associated with an air handler of the HVAC/R system based on the received signals from the sensors, determine a second energy transfer value associated with the refrigerant of the HVAC/R system based on the pressure-enthalpy relationship and the received signals from the sensors; and verify the determined first and second energy transfer values by comparing the first energy transfer value with the second energy transfer value.

Techniques for determining and using a thermodynamic model that characterizes a thermodynamic response of an enclosure conditioned by an HVAC system are disclosed. To determine a thermodynamic model, temperature information when the HVAC system operates in a first state may first be received. A response interval may then be determined where the response interval indicates an estimated time between when the HVAC system begins operating in the first state and when the temperature within the enclosure begins to change in a direction associated with the first state. Weighting factors corresponding to basis functions may then be determined, where the weighted basis functions characterize the temperature trajectory of the enclosure in response to the HVAC system operating in the first state. The basis functions may include a first basis function that is evaluated from a time that the HVAC system begins operating in the first state until a time when the response interval ends, and a second basis function that is evaluated beginning at the time when the response interval ends.

A power monitoring system includes a plurality of current sensors suitable to sense respective changing electrical current within a respective conductor to a respective load and a conductor sensing a respective voltage potential provided to the respective load. A power monitors determines a type of circuit based upon a signal from at least one of the current sensors and a signal from the conductor, wherein the type of circuit includes at least one of a single phase circuit, a two phase circuit, and a three phase circuit. The power meter configures a set of registers corresponding to the determined type of circuit in a manner such that the configuring is different based upon each of the single phase circuit, two phase circuit, and three phase circuit suitable to provide data corresponding to the determined type of circuit.

A monitoring system is disclosed for a heating, ventilation, or air conditioning (HVAC) system of a residential or commercial building. The monitoring system includes an evaporator unit device including a first current sensor that measures current supplied to a circulator blower. The measured current from the first current sensor is used to diagnose a problem with the circulator blower. The monitoring system includes a first temperature sensor that measures refrigerant temperature between a condenser and an expansion valve. The monitoring system includes a second temperature sensor that measures refrigerant temperature between an evaporator and a compressor. The monitoring system includes a condenser unit device that communicates with the evaporator unit device. The condenser unit device includes a second current sensor that measures current supplied to the compressor. The evaporator unit device transmits sensor data to a remote monitoring service over a data network.

A power monitoring system includes a plurality of current sensors suitable to sense respective changing electrical current within a respective conductor to a respective load and a conductor sensing a respective voltage potential provided to the respective load. A power monitors determines a type of circuit based upon a signal from at least one of the current sensors and a signal from the conductor, wherein the type of circuit includes at least one of a single phase circuit, a two phase circuit, and a three phase circuit. The power meter configures a set of registers corresponding to the determined type of circuit in a manner such that the configuring is different based upon each of the single phase circuit, two phase circuit, and three phase circuit suitable to provide data corresponding to the determined type of circuit.

Systems and methods implementing a frost sensor comprising a substrate (S); and sub-sensors disposed on the substrate. The sub-sensors comprising: a resistance-based sub-sensor (RSS) formed of a first trace disposed on S in a winding pattern and configured to measure a temperature; a capacitance-based sub-sensor formed of a second trace defining a first electrode and a third trace defining a second electrode (wherein (i) the first and second electrodes comprise interdigitated fingers or other interdigitated structures (including, but not limited to, round, spiral interdigitated electrodes, etc.) configured to detect a change in capacitance due of frost, ice or water, and (ii) the second trace is integrally formed with the first trace); and another RSS formed of a fourth trace defining a third electrode and a fifth trace defining a fourth electrode (wherein (i) the third and fourth electrodes comprise interdigitated fingers or other interdigitated structures (including, but not limited to, round, spiral interdigitated electrodes, etc.) configured to detect a change in resistance due to the frost, ice or water, and (ii) the fourth trace is integrally formed with the third trace).

A method for self-diagnosing an ultrasonic flowmeter assembly (I) comprising at least one ultrasonic transducer (20, 21) fixed to the conduit section (3) and configured to emit ultrasonic pulses into the conduit (3) and to receive ultrasonic pulses after having travelled along at least one path (R, I) in the conduit section (3) and to output measurement data, further comprising a controller (200) for processing the measurement data, wherein a reference measurement and test measurement each comprises emitting and receiving at least one ultrasonic pulse along at least one same or comparable path (R). The method comprises: (a) providing a reference measurement data; (b) obtaining a test measurement data; (c) comparing the reference and test measurement data, wherein the reference measurement data (A) comprises an ultrasonic reference signal characteristic (51,61), and the test measurement data (B) comprises an ultrasonic test signal characteristic (52, 62).

The invention involves the automated testing of HVAC units using an energy management system. The automated HVAC test is performed to understand if one or more HVAC units are operational across one or more locations. If an HVAC unit is not operational, HVAC testing could be performed to understand which component or stage of the HVAC unit is not working as designed. The automated HVAC test is also used to calculate the efficiency of the HVAC unit(s) being tested. The various HVAC tests are performed on all HVAC units as a form of preventative maintenance and diagnostics. These tests can be scheduled on-demand, for a future date and time, or on a recurring schedule (monthly or quarterly). A report is generated for each HVAC test and can be viewed and exported from a cloud-based energy management platform.

An estimation method includes an acquisition step, a kriging step, and a longitudinal extension step. The kriging step includes obtaining a distribution of the environmental value on a reference plane by kriging method based on a measured value of the environmental value at a measuring point of a sensor. The longitudinal extension step includes obtaining a distribution of the environmental value in a height direction in a longitudinal region based on the environmental value obtained in the kriging step with respect to a specified point on a reference plane and a function representing a variation in the environmental value in the height direction. The longitudinal region includes the specified point on the reference plane and extends in the height direction.

Systems and methods implementing a frost sensor comprising a substrate (S); and sub-sensors disposed on the substrate. The sub-sensors comprising: a resistance-based sub-sensor (RSS) formed of a first trace disposed on S in a winding pattern and configured to measure a temperature; a capacitance-based sub-sensor formed of a second trace defining a first electrode and a third trace defining a second electrode (wherein (i) the first and second electrodes comprise interdigitated fingers or other interdigitated structures (including, but not limited to, round, spiral interdigitated electrodes, etc.) configured to detect a change in capacitance due of frost, ice or water, and (ii) the second trace is integrally formed with the first trace); and another RSS formed of a fourth trace defining a third electrode and a fifth trace defining a fourth electrode (wherein (i) the third and fourth electrodes comprise interdigitated fingers or other interdigitated structures (including, but not limited to, round, spiral interdigitated electrodes, etc.) configured to detect a change in resistance due to the frost, ice or water, and (ii) the fourth trace is integrally formed with the third trace).