Abstract: A system is provided to optimize multiple boiler plant systems having mixed condensing and non-condensing boiler groups. The system advantageously employs the independent groups of boilers depending on preset conditions under control of a system control unit. The preset conditions are checked against operating conditions of the boiler plant, and a system control unit controls which of the groups of boilers is the lead and which is secondary. In some instances, both groups of boilers may be utilized under heavy load. Further, effective switching between groups and within groups is also provided to minimize unnecessary repetitive boiler operation.

Abstract: A system and method for monitoring remote equipment such as HVAC equipment, are provided. A sensor is in communication with a piece of remote equipment. An interface unit, having a message generating mechanism, is capable of receiving signals from the sensors. A central computer server is in communication with the interface unit and is adapted to receive and preferably store messages generated by the interface unit from a variety of different data transports. When a sensor detects an exception condition in a piece of remote equipment, the sensor transmits a signal to the interface unit, and the interface unit generates an incoming exception message and forwards the message to the server. The server forwards at least one outgoing exception message to at least one predetermined user-defined communication device based on the incoming exception message.

Abstract: A system for routing messages electronically is provided. A sensor is in communication with a central computer server. The server is adapted to receive and preferably store information detected by the sensors from a variety of different data transports. When a sensor detects an exception condition , the server forwards at least one outgoing exception message to at least one predetermined user-defined communication device based on and in accordance with a user-defined message profile. The message profile is remotely configurable by the user.

Abstract: A system and method for monitoring remote equipment are provided. An interface unit, having a message generating mechanism, is capable of receiving signals from sensors. A central computer server is in communication with the interface unit and is adapted to receive and preferably store messages generated by the interface unit from a variety of different data transports. If a sensor detects an exception condition in a piece of remote equipment, the sensor transmits a signal to the interface unit, and the interface unit generates an incoming exception message and forwards the message to the server. The server forwards at least one outgoing exception message to at least one predetermined user-defined communication device based on the incoming exception message. The interface unit may in addition or instead transmit normal status messages if the equipment and/or interface unit is functioning properly. The message profile is remotely configurable by the user.

Abstract: A system and method for monitoring remote equipment such as HVAC equipment, are provided. A sensor is in communication with a piece of remote equipment. An interface unit, having a message generating mechanism, is capable of receiving signals from the sensors. A central computer server is in communication with the interface unit and is adapted to receive and preferably store messages generated by the interface unit from a variety of different data transports. When a sensor detects an exception condition in a piece of remote equipment, the sensor transmits a signal to the interface unit, and the interface unit generates an incoming exception message and forwards the message to the server. The server forwards at least one outgoing exception message to at least one predetermined user-defined communication device based on the incoming exception message.

Abstract: A control system for a cooling system for reducing humidity levels in a gas such as ambient air is provided. The cooling unit includes at least one of a compressor and a chiller, and cooling coils are connected to the cooling unit. A fan blows the gas onto the cooling coils. A fan speed controller is connected to the fan and variably controls the speed of the fan. A dry bulb temperature sensor is in thermal communication with the gas and connected to the controller, and a moisture sensor is in communication with the gas and connected to the controller. The speed of the fan is determined by the controller based on signals received from the dry bulb temperature sensor and the moisture sensor. By varying the speed of the fan, the moisture content of the gas can be modified much more precisely than by conventional air conditioning methods.

Abstract: A system and method for monitoring remote equipment such as HVAC equipment, are provided. A sensor is in communication with a piece of remote equipment. An interface unit, having a message generating mechanism, is capable of receiving signals from the sensors. The interface unit is provided with a programmable logic controller which performs Boolean operations or expressions on the signals received by the sensors. A central computer server is in communication with the interface unit and is adapted to receive and preferably store messages generated by the interface unit. When a sensor detects an exception condition in a piece of remote equipment, the sensor transmits a signal to the interface unit, and the interface unit generates an incoming exception message and forwards the message to the server. The server forwards at least one outgoing exception message to at least one predetermined user-defined communication device based on the incoming exception message.

Abstract: A valve modulation method and a system utilizing the method is provided. In a hydronic heating system having primary and secondary loops, a simple two-position valve is powered on an intermittent duty cycle to regulate the amount of flow of boiler water from the primary loop to a radiation system in the secondary loop. The actuator of the valve is pre-powered so that it is fully responsive to this intermittent duty cycle. By only supplying power to the actuator of the valve intermittently, the piston of the valve remains in a partially open position, and allows some flow to pass from the primary loop to the secondary loop. The position of the valve remains constant, owing to the duty cycle being shorter than the response time of the valve. By pre-powering the valve, the lag time it takes for the valve to become responsive to changes in the duty cycle is significantly reduced or eliminated. In this fashion, the temperature of the water in the secondary loop may be controlled.

Abstract: A remote controlled system for remotely controlling a high load device, such as the defrosting cycle of a self-defrosting refrigerator, is provided. The system includes a data interface to receive commands from an electricity supplier and to transmit those commands via the power line to the refrigerator. The refrigerator is equipped with a power line interface to receive the commands from the power line and transmit the commands to a defrost sequencer. Between the power line interface and the defrost sequencer may be provided another interface that converts the commands into a digital signal more suitable for the defrost sequencer, which is typically a microprocessor.

Abstract: A passive injection system for a hydronic heating system having a primary loop and a secondary loop is described. The passive injection system establishes a secondary temperature in the secondary loop significantly different from the temperature of the primary or boiler loop. A Venturi tee passively induces flow from the primary loop to the secondary loop. A valve is provided in the flow path of the Venturi tee between the primary and secondary loops and allows some flow or no flow from the primary loop to enter and mix with the secondary loop, depending upon whether the valve is open, closed, or partially open. A return leg is provided at a tee connection for returning flow from the secondary loop to the primary loop. In this way, the temperature of the secondary loop can be set well below the temperature of the primary loop and can be controlled without changing the flow rate of the secondary loop.

Abstract: A snow and ice melt control system is provided to melt snow and ice from a slab, a temperature sensor means are provided at the input and output from the slab, and a differential temperature is generated reflecting the condition of the slab in respect to the ambient temperature. A controller is provided to adjust the amount of heat and heated fluid flowing to the slab to actively respond to environmental conditions to more efficiently melt snow and ice on the slab.

Abstract: A multiple-boiler heating system is disclosed in which each boiler or stage is provided with an adjustable firing level of modulation at which the boiler is turned on and an adjustable threshold level of modulation (the MOD point), below which the next stage is disabled from being turned on. A control device for the heating system continuously compares temperature in the area being heated to the set point for the system and determines the total change in system output level ("DUTYCHANGE") which would be required to produce a specified temperature within a predetermined time. Should DUTYCHANGE be negative, it is similarly distributed among the stages which are turned on. However, the reduction in modulation level proceeds backwards from the last stage which was turned on. When the last stage reaches its firing point, it is not turned off until the previous stage drops below its MOD point. The lead stage is turned off as soon as it reaches its firing point.

Abstract: In a thermostatic control system a solid state motor controller is provided by reproducing a potentiometer tracking with a CPU producing appropriate complimentary square wave signals having the duty cycle thereof proportional to a sensed temperature. The square wave signals are fed to circuits which are disposed across two output resistors and the effective resistance of the two resistors are varied in response to the duty cycle.

Abstract: A control device for a hot water heating system which has a boiler, water pump and motor control mixing valve. The control device is responsive to the outside temperature for turning the pump on and off when the outside temperature drops below or exceeds a predetermined pump set point. A set of water reset ratios is defined and a range of offset adjustments are provided for each ratio and are selected for controlling the heat level within the system. The desired water temperature is periodically determined for the output of the mixing valve for the selected water reset ratio and offset and is receptive of the actual water temperature for comparing the actual water temperature to the desired water temperature. The mixing valve is then controlled by opening or closing same to make the actual water temperature correspond to the desired or computed water temperature.

Abstract: A heating system control device is responsive to the drop in outside temperature to below a predetermined weatherhead set point for turning on a heating system to be controlled. Upon the establishment of the heat in the heating system, a defined heating cycle is carried out consisting of a heat-on portion and a heat-off portion having a duty cycle dependent on the outside temperature. The heating cycle does not start until there is an establishment of heat in the heating system. The start of consecutive heating cycles is delayed in response to a check for heat loss in the system. When heat is established and the set point has not been reached, as noted by the means for determining the establishment of heat in the heating system, the next cycle will be delayed to save energy.