A system and method to evaluate building cooling fuel consumption with the aid of a digital computer is described. The evaluation can be used for quantifying personalized electric and fuel bill savings. Such savings may be associated with investment decisions relating to building envelope improvements; HVAC equipment improvements; delivery system efficiency improvements; and fuel switching. The results can also be used for assessing the cost/benefit of behavioral changes, such as changing thermostat temperature settings. Similarly, the results can be used for optimizing an HVAC control system algorithm based on current and forecasted outdoor temperature and on current and forecasted solar irradiance to satisfy consumer preferences in a least cost manner. Finally, the results can be used to correctly size a photovoltaic (PV) system to satisfy needs prior to investments by anticipating existing energy usage and the associated change in usage based on planned investments.

An air conditioning system comprises one or more air conditioners through which refrigerant circulates, and a first controller. For each of one or more indoor units, a score corresponding to a cost of using the indoor unit is preset. The first controller calculates, for each of the one or more air conditioners, a first total value of a score of each of the one or more indoor units included in the air conditioner. The first controller calculates a second total value of the first total value of each of the one or more air conditioners. When an electrical energy limit condition is satisfied, the first controller sets for each of the one or more air conditioners a drive frequency for a compressor included in the air conditioner according to a ratio of the first total value of the air conditioner to the second total value.

A thermostat for a building zone includes at least one of a model predictive controller and an equipment controller. The model predictive controller is configured to obtain a cost function that accounts for a cost of operating HVAC equipment during each of a plurality of time steps, use a predictive model to predict a temperature of the building zone during each of the plurality of time steps, and generate temperature setpoints for the building zone for each of the plurality of time steps by optimizing the cost function subject to a constraint on the predicted temperature. The equipment controller is configured to receive the temperature setpoints generated by the model predictive controller and drive the temperature of the building zone toward the temperature setpoints during each of the plurality of time steps by operating the HVAC equipment to provide heating or cooling to the building zone.

A heating, ventilation, and air conditioning (HVAC) control device is configured to record a plurality of actual occupancy statuses, to determine a plurality of corresponding predicted occupancy statuses, and to compare the plurality of predicted occupancy statuses to the plurality of actual occupancy statuses. The device is further configured to identify conflicting occupancy statuses based on the comparison. A conflicting occupancy status indicates a difference between an actual occupancy status and a corresponding predicted occupancy status. The device is further configured to identify timestamps corresponding with the conflicting occupancy statuses, to identify historical occupancy statuses corresponding with the identified timestamps, and to update the conflicting occupancy statuses in the predicted occupancy schedule with the historical occupancy statuses.

A method of controlling operation of an air conditioning system (10) includes measuring a compressor speed of one or more chillers (12) of an air conditioning system and measuring a refrigerant pressure of the one or more chillers of the air conditioning system. A chiller load is calculated using the compressor speed and the refrigerant pressure. An air conditioning system includes one or more chillers. Each chiller includes a compressor (22), a condenser (30) operably connected to the compressor, and an evaporator (28) operably connected to the compressor and the condenser. A controller (34) is operably connected to the one or more chillers and is configured to calculate a chiller load utilizing a measurement of compressor speed and a measurement of refrigerant pressure of the chiller.

A control system for an HVAC system having a plurality of HVAC components operably associated with one or more terminal units is provided. The control system includes a coordination module and a controller having a processor and a memory, the controller operably associated with the coordination module and in signal communication with the plurality of HVAC components. The controller is configured to determine an aggregated thermal demand of the HVAC system, determine, with the coordination module, an operational setpoint for at least one HVAC component of the plurality of HVAC components based on the determined aggregated thermal demand, and send a signal indicative of each determined operational setpoint to each associated HVAC component of the plurality of HVAC components.

An HVAC system within a building including an HVAC device having an air filter, a number of sensors, and a control device. The control device has a processor that is configured to determine a current air quality metric based on air quality measurements received by the sensor. The control device is further configured to calculate an average air quality metric based on the current air quality metric and a set of previous air quality metrics. The control device is further configured to store the average air quality metric. The control device is further configured to generate an air filter type recommendation based on the average air quality metric.

A thermostat may include one or more memory devices comprising a stored setpoint schedule, one or more temperature sensors configured to provide temperature sensor measurements, and a processing system configured to be in operative communication the one or more memory devices to determine a setpoint temperature, and in still further operative communication with a heating, ventilation, and air conditioning (HVAC) system to control the HVAC system based at least in part on the setpoint temperature and the temperature sensor measurements. The processing system may be configured to control the HVAC system by receiving an indication that a total instantaneous energy usage rate for a structure in which the thermostat is installed is projected to exceed a threshold amount; and altering the stored setpoint schedule to reduce an energy usage rate of the HVAC system.

The present disclosure relates to a method for primary frequency regulation of an electric network based on large building air conditioning loads cluster. The method includes the use of a two layer control structure with a central coordinating layer and a local control layer. Each local controller performs a thermal model parameter identification and a local air conditioning autonomous control, and uploads local information to the central controller at the end of each communication interval t.sub.gap, the central controller broadcasts coordinating information to each local controller. Based on the coordinating information sent from the central controller, each local controller determines whether a power deviation is beyond an action dead zone at the beginning of each action period t.sub.act, if beyond, then perform a frequency regulation control action, else, perform no action and estimate operation states of all the air conditionings at the beginning of the next action period.

The present disclosure provides an air conditioner. The air conditioner includes a compressor; a sensor for measuring the compressors state configured to detect compressor state information that includes at least one of a pressure value and a saturation temperature of the compressor; and a controller configured to control air flow on the side of an indoor unit by comparing the compressor state information measured from the sensor and a threshold.