A thermostat includes: a controller adapted to control the function of an associated HVAC system; and user controls adapted to provide instructions to the controller including selecting between heating functions and cooling functions, wherein the controller is limited by a maximum temperature when heating functions are selected and limited by a minimum temperature when the cooling functions are selected, wherein the maximum temperature is a lower temperature than the minimum temperature.

The present invention can provide an optimum sensory temperature and can increase productivity by a system having a variable fan provided in a vinyl greenhouse, receiving optimum temperature (A) and humidity (B), detecting internal temperature (A′) and humidity (B′), calculating temperature (A″) according to the humidity, and providing the temperature (A″) suitable for the humidity (B′) detected through an operational control of the variable fan.

An HVAC control system is provided that is configured to prompt a user to indicate whether or not they are comfortable under current environmental conditions. In some instances the HVAC control system may be configured to prompt the user to provide additional information regarding other factors that may affect their comfort. The HVAC control system may use the information collected from the user to control an HVAC system to achieve and/or maintain an environmental condition within a building at a level at which the user is expected to be comfortable.

A switch circuit configured to receive power from either a single power source or dual power source. The circuit includes two power input terminals and two power output terminals. For a single power source, the switch circuit may receive the single power source at either of the two power input terminals. The switch circuit provides power to a load without regard to which of the power input terminals the single power source is connected. The switch circuit shorts the power output terminals for a single power input, which provides power at both power output terminals. For a dual power source system, the switch circuit may isolate the two power output terminals so each power output terminal may operate independently without shorting. In some examples, the switch circuit may be part of a thermostat or similar HVAC system controller.

A system for controlling a combustion appliance based on one or more localized environmental factors and an inlet/exhaust system enclosed within a single enclosure. The control system includes an electrically controlled fuel valve, coupled to a source of combustion appliance fuel, and responsive to a fuel valve control signal, for controlling the flow of fuel to the appliance. An air pressure detector is disposed in an area proximate the combustion appliance and configured for detecting negative air pressure in the proximate area and in response for providing a negative air pressure detection signal to a relay which will deactivate the fuel valve until negative air pressure is not present thereby preventing operation of the combustion appliance. Further, if negative air pressure is detected, the relay energizers a makeup air device to bring an outside air into the area near the combustion appliance.

Systems and methods can control refrigeration within a refrigerated freight container. Thermal sensor nodes can be positioned within the freight container. Temperature measurements can be wirelessly relayed from the sensor nodes to a gateway associated with the freight container. The received temperature measurements can be aggregated and logged at the gateway. Thermal models of the freight container and associated cargo loads can be established in response to the logged temperature measurements and loading plan for the foreign container. The refrigeration system can be controlled in response to processing the thermal models. The refrigeration system can be controlled to optimize compliance parameters associated with the cargo loads.

A climate controller having a control unit operable to activate and de-activate an HVAC unit, a temperature sensor and a humidity sensor operable to communicate temperature and relative humidity measurements to the control unit, and an interface to a network through which the control unit is operable to connect to a networked server and transmitting measurements for temperature and relative humidity; the control unit operable to activate and de-activate the HVAC unit according to the control unit operable to measure a temperature and humidity level, operable to obtain a value for a temperature setting and mode of operation for the HVAC unit, and operable to communicate a signal to the HVAC unit to effect the activation or de-activation. Climate control is achieved with reference to a comfort level temperature, and energy efficiency is achieved through the application of machine learning methods operated on data sets gathered by the climate controller.

A heating fluid control system determines the aggregated demand for heating fluid from a plurality of sources of demand in a building and deactivates a boiler that provides the heating fluid when the aggregated demand is zero. The sources of demand can include radiators and domestic hot water fixtures. Valves that control the flow of heating fluid from the boiler to these sources of demand can transmit signals representative of the position of the valve. A controller can use these signals and other signals to determine the demand for heating fluid from each source of demand. The controller evaluates the signals to determine the aggregate system demand. And after deactivating the boiler, the controller can reactivate the boiler when the aggregate system demand is determined to be non-zero. Methods of using such heating systems are also disclosed.

A thermostat includes: a controller adapted to control the function of an associated HVAC system; and user controls adapted to provide instructions to the controller including selecting between heating functions and cooling functions, wherein the controller is limited by a maximum temperature when heating functions are selected and limited by a minimum temperature when the cooling functions are selected, wherein the maximum temperature is a lower temperature than the minimum temperature.

A heating device (100) comprises: a heater (10) for heating an item (1) to be heated; a temperature detection unit (20) for detecting the temperature of the item (1); and a temperature adjustment unit (30) for controlling the heater (10) on the basis of a target temperature and the detected value of the temperature detection unit (20) so that the temperature of the item (1) reaches the target temperature. The heating device (100) determines, as a system gain change rate, the rate of change from the initial value of a system gain determined as a ratio of a temperature increase value of the item (1) with respect to electric power inputted to the heater (10), and determines the rate of change in the heat-retaining properties of the item (1) using the system gain change rate.