摘要:
Fan coil thermostats can provide energy savings by, for example, operating a fan coil system more efficiently. Fan coil systems employing such a fan coil thermostat may be more energy efficient. A fan coil system may include a fan coil that is configured for fluid communication with a source of heated fluid and/or a source of cooled fluid, a valve that controls fluid flow through the fan coil and a fan that blows air across the fan coil. The fan coil thermostat may include a controller that implements a control algorithm that calculates an error percentage value relating to a temperature difference between the current temperature and the temperature set point. The error percentage value may include a proportional term related to the temperature difference and an integral term related to the temperature difference. The controller may regulate the fan speed in accordance with the calculated error percentage.
摘要:
Methods for controlling an economizer of an HVAC system are disclosed. An illustrative control method may include positioning one or more controllable dampers in first and second configurations such that a mixed air stream has first and second mixing ratios of incoming outside air to return air. First and second measures related to the temperature of the mixed air stream may be recorded when the dampers are in each of the first and second configurations. Based on the recorded first and second measures, it may be determined whether and/or how much of the incoming outside air to admit into the economizer via the one or more controllable dampers during subsequent operation of the HVAC system.
摘要:
The present disclosure provides a method for controlling an economizer of an HVAC system. The economizer has an outside air stream of incoming outside air, a return air stream of return air, and a mixed air stream of mixed incoming outside air and return air that is provided to the cooling unit of the HVAC system. The economizer also includes one or more controllable dampers for controlling a mixing ratio of incoming outside air to return air in the mixed air stream. The control method includes positioning the one or more controllable dampers in first and second configurations such that the mixed air stream has first and second mixing ratios of incoming outside air to return air in the mixed air stream. The method also includes recording first and second measures related to the temperature of the mixed air stream when the dampers are in each of the first and second configurations. First and second measures related to other parameters of the mixed air stream may be recorded as well. Based on the recorded first and second measures related to the temperature of the mixed air stream and possibly other recorded measures related to mixed air stream parameters, the method determines whether and/or how much of the incoming outside air to admit into the economizer via the one or more controllable dampers during subsequent operation of the HVAC system.
摘要:
An approach to automatically encode application enumeration values to enable reuse of applications across controller of different protocols. Protocols may use different sets of enumerations to denote various application values and states. The present approach may permit defining a common set of enumerations which can be encoded automatically by a tool that enables reuse. Application designers may define enumerations to be used by the control application and the tool will automatically encode them into communication protocol specific enumeration values.
摘要:
A variable velocity calibration and balancing system having a basis in a function block engine. It pertains to variable air volume systems and particularly to balancing systems as they relate to heating, ventilation and air conditioning (HVAC) systems. Balancing may be addressed using functional blocks to represent actual control and connections in an HVAC application for a variable air volume application.
摘要:
A system PDA-based on line diagnostics for automatically discovering a thermostat configuration, turning off normal controller delays, temporary overriding sensor inputs and set points, and verifying proper output action including the monitoring the discharge air temperature for the resulting temperature behavior based on the equipment stages activated. The diagnosis may include the testing of sensors, set points, the fan, cooling equipment, heating equipment and the wiring connecting the controls with the fan, and the cooling and heating equipment. Problems discovered may be reported, automatically recorded and the original operating parameters may be restored.
摘要:
Methods and apparatus for using humidity level to adjust the temperature set point of an HVAC system for increased occupant comfort. In one illustrative embodiment, the temperature set point for the inside space is moved downward when the humidity of the inside space rises above a predetermined humidity set point threshold value. In warm climates, this causes the air conditioner of the HVAC system to be activated, which lowers the temperature of the inside space to a new lower temperature set point. In some embodiments, the HVAC system retains the new lower temperature set point for a predetermined time period. The predetermined time period may be dependent on a number of factors, including whether the space is expected to occupied or unoccupied.
摘要:
Methods and systems for automatically calibrating one or more damper positions of a demand control ventilation system are disclosed. In one illustrative embodiment, a demand control ventilation system includes a damper for controlling a flow of outside air into a building. A controller may be programmed to automatically execute a calibration algorithm from time to time to calibrate one or more calibration damper positions such that a predetermined flow of outside air is drawn through the damper and into the building at each of the one or more calibration damper positions. This calibration can, in some instances, help increase the efficiency and/or utility of the demand control ventilation system.
摘要:
The present disclosure provides a method for operating an HVAC system for conditioning air of an inside space. The HVAC system has an economizer configured to control the intake of outside air into an HVAC air stream of the HVAC system. The method includes determining at least two parameters of the air of the inside space, where the at least two parameters are selected from a set of parameters from which an inside air dry bulb temperature, an inside air dew point, an inside air relative humidity, and an inside air enthalpy can be determined, either directly or indirectly. The method also includes determining at least two parameters of the outside air, where the at least two parameters being selected from a set of parameters from which an outside air dry bulb temperature, an outside air dew point, and an outside air enthalpy can be determined, either directly or indirectly. Based on one or more of the inside air dry bulb temperature, the inside air dew point, the inside air relative humidity, and the inside air enthalpy, a determination is made of whether dehumidification of the inside space is needed, and if dehumidification is not needed, the economizer is commanded to increase the intake of outside air into the HVAC air stream if the outside air dry bulb temperature is less than a dry bulb temperature reference, and if the outside air enthalpy is less than an enthalpy reference. If, alternatively, dehumidification is needed, the economizer is commanded to increase the intake of outside air into the HVAC air stream if the outside air enthalpy is less than the enthalpy reference, and if the outside air dew point is less than a dew point reference.
摘要:
A system having a function block execution framework. Function blocks may be for use in a control system design. These blocks may be selected from a library of a function block engine. Selected function blocks may be executed for operational purposes. They may be continuously executed by a processor to maintain operational status. However, since a function block engine and a resulting system of function blocks may be operated with battery power, executions of function blocks may be reduced by scheduling the executions of function blocks to times only when they are needed. That means that the processor would not necessarily have to operate continuously to maintain continual execution of the function blocks and thus could significantly reduce consumption of battery power.