A water heating system can include a water heater having a tank, and a first temperature sensor disposed toward a top end of the tank to measure a first temperature and a second temperature sensor disposed toward a bottom end of the tank to measure a second temperature. The water heating system can further include a controller communicably coupled to the first temperature sensor and the second temperature sensor, where the controller determines an amount of heated water in the tank based on a plurality of algorithms and measurements made by the first and second temperature sensors. The plurality of algorithms solves for at least one calculated temperature for at least one point between a first location of the first temperature sensor and a second location of the second temperature sensor, where the at least one calculated temperature is used to determine the amount of heated water in the tank.

Appropriate ventilation for a building space while maintaining building comfort includes tracking one or more interior environmental conditions within the building space and one or more exterior environmental conditions outside of the building space during operation of the HVAC system. An environmental model for the building space is learned over time based at least in part on these tracked environmental conditions, where the environmental model predicts an environmental response of the building space to operation of the HVAC system under various interior and exterior environmental conditions. An appropriate ventilation rate that maintains adherence to one or more comfort parameters of the building space is determined by using the environmental model of the building space. The outdoor air ventilation damper of the HVAC system is controlled to provide appropriate ventilation.

Appropriate ventilation for a building space while maintaining building comfort includes tracking one or more interior environmental conditions within the building space and one or more exterior environmental conditions outside of the building space during operation of the HVAC system. An environmental model for the building space is learned over time based at least in part on these tracked environmental conditions, where the environmental model predicts an environmental state of the building space in response to operation of the HVAC system under various interior and exterior environmental conditions. A maximum allowed ventilation rate that can be achieved without causing the HVAC system to compromise on any of one or more comfort conditions of the building space is predicted using the environmental model. The outdoor air ventilation damper of the HVAC system is then controlled to provide an appropriate ventilation up to or at the predicted maximum allowed ventilation rate.

Various embodiments include a method of controlling heat exchange via a terminal unit of a terminal-side circuit of a system for HVAC with a source-side circuit coupled to the terminal-side circuit comprising: reading a terminal-side supply temperature signal; producing a supply temperature from the terminal-side supply temperature signal; estimating a percentage demand signal as a function of the supply temperature; estimating an actual demand for power by rescaling a value of maximum available power by the percentage demand signal; comparing the actual demand for power to the value of maximum available power; and if the actual demand for power exceeds the value of maximum available power: producing a first flow control signal based on the value of maximum available power; and controlling a flow of a fluid through the source-side circuit based on the first flow control signal.

A water heating system can include a water heater having a tank, and a first temperature sensor disposed toward a top end of the tank to measure a first temperature and a second temperature sensor disposed toward a bottom end of the tank to measure a second temperature. The water heating system can further include a controller communicably coupled to the first temperature sensor and the second temperature sensor, where the controller determines an amount of heated water in the tank based on a plurality of algorithms and measurements made by the first and second temperature sensors. The plurality of algorithms solves for at least one calculated temperature for at least one point between a first location of the first temperature sensor and a second location of the second temperature sensor, where the at least one calculated temperature is used to determine the amount of heated water in the tank.

A system and related method to analyze operation of a heating system of a building based on fuel consumption and fuel demand of the building. The system includes a database of information about the heating system of the building, a first sensor set arranged to gather fuel consumption information and a second sensor set arranged to gather fuel demand information within the building. The system includes a fuel usage and demand analysis function configured to analyze data from the first sensor set and from the second sensor set to output a determination of operation of the heating system based on consumption information and demand information.

A CHP optimal dispatching model is a mixed integer programming model and is used for a district heating system (DHS) comprising a heat source, a heating network and a heat load, and the heating network comprises a heat transmission network and a heat distribution network. A plurality of heating areas is divided, and one day is divided into a plurality of time periods; the heat transmission loss of the heat distribution network is omitted, and a heat transmission network model taking transmission time delay of the heating network into consideration is established according to the heat transmission network; a terminal heat consumer model capable of reflecting indoor temperature is established; and a combined optimal dispatching model comprising conventional generators, wind power units, CHP units, electric boilers and heat storage tanks is established.

Appropriate ventilation for a building space while maintaining building comfort includes tracking one or more interior environmental conditions within the building space and one or more exterior environmental conditions outside of the building space during operation of the HVAC system. An environmental model for the building space is learned over time based at least in part on these tracked environmental conditions, where the environmental model predicts an environmental state of the building space in response to operation of the HVAC system under various interior and exterior environmental conditions. A maximum allowed ventilation rate that can be achieved without causing the HVAC system to compromise on any of one or more comfort conditions of the building space is predicted using the environmental model. The outdoor air ventilation damper of the HVAC system is then controlled to provide an appropriate ventilation up to or at the predicted maximum allowed ventilation rate.

A system for determining the relative space heating energy contribution of different tenant spaces in a multiple tenant building that is heated via a central steam piping distribution system. A steam piping distribution system is connected to a central heat source such as a steam boiler plant or a local utility district steam service. The steam distribution system includes terminal units located throughout the building which deliver heat to different spaces. Data collected at regular intervals from sensors located throughout the building are analyzed by a computer in order to calculate the fraction of the overall building's steam use that is delivered to particular tenant spaces over a given interval in time.

There are provided systems and methods for monitoring a property using a system of sensor units in one or more premises on the property that can interface with respective utilities entering the premises or being generated by appliances on the premises with a minimal of effort and without requiring modification of the utility's equipment or the appliance. The systems and methods are connectable to a cloud-based monitoring, analytics and notification system via a long range network connection directly from one or more of the sensor units. The system of sensors can also incorporate primary and secondary units with at least one primary unit capable of communicating directly to the cloud-based system/server via a long-range connection with the secondary units sending data to the cloud via the primary unit by communicating at the property via a short-range communication connection. There are also provided various sensor units for specifically monitoring water flow and water leakage, flooding, sump pump operability, levels within water softeners and other fluid containing vessels, electrical power usage, furnace operations, among others as described herein.