In accordance with the principals of the present invention, a furnace unit adapted to be installed in-line with a fuel source of a furnace modulates natural gas or propane to reduce fuel consumption, minimize temperature overshoot, and reduce furnace short cycling. A modulator is contained with the furnace unit. The modulator is in gaseous communication with the in-line gas fuel source. A furnace sensor senses furnace criteria related to the operation of the furnace. A microcontroller receives from the furnace sensor furnace criteria and controls the modulator based on the furnace criteria. In a further aspect of the invention, an environmental sensor can be provided to sense environmental criteria related to the operation of the furnace. In a further aspect of the invention, a base unit in electrical communication with the furnace unit can be provided, the base unit determining energy consumption usage and savings. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims

A heat-pump circuit may include an indoor heat exchanger, an outdoor heat exchanger, a compressor adapted to circulate a working fluid between the indoor and outdoor heat exchangers, and an expansion device disposed between the indoor and outdoor heat exchangers. A monitor for the heat-pump system may include a return-air temperature sensor, a supply-air temperature sensor, and a processor. The return-air temperature sensor may be adapted to measure a first air temperature of air upstream of the indoor heat exchanger. The supply-air temperature sensor may be adapted to measure a second air temperature of air downstream of the indoor heat exchanger. The processor may be in communication with the return-air temperature sensor and the supply-air temperature sensor. The processor may be programmed to determine a working-fluid-charge condition of the heat-pump system based on the first and second air temperatures.

A movable fluid fuel heater to heat air and to introduce it into an environment to be heated. The heater includes a flow rate variator device for varying the flow rate of oxidizing air introduced in the combustion chamber by a forced ventilation device between a minimum flow rate value and a maximum flow rate value. The heater also includes a reference device comprising a plurality of reference values of a parameter representative of the pressure and a plurality of reference temperature values of the environmental air upstream of the combustion chamber. The reference device is configured to suggest an optimal setting value to set the flow rate variator device, at each pair of values formed by a value of the plurality of reference values of a parameter representative of the pressure and a value of the plurality of reference temperature values.

An orifice 26 is provided in an air supply passage 5a of a warm air heater 100, and a differential pressure sensor 28 detects differential pressure p between front and rear of the orifice 26 in the air supply passage 5a. Rotation speed of the combustion fan 24 is corrected on the basis of the differential pressure p detected by the differential pressure sensor 28.

A movable fluid fuel heater to heat air and to introduce it into an environment to be heated. The heater includes a flow rate variator device for varying the flow rate of oxidizing air introduced in the combustion chamber by a forced ventilation device between a minimum flow rate value and a maximum flow rate value. The heater also includes a reference device comprising a plurality of reference values of a parameter representative of the pressure and a plurality of reference temperature values of the environmental air upstream of the combustion chamber. The reference device is configured to suggest an optimal setting value to set the flow rate variator device, at each pair of values formed by a value of the plurality of reference values of a parameter representative of the pressure and a value of the plurality of reference temperature values.

A heat-pump circuit may include an indoor heat exchanger, an outdoor heat exchanger, a compressor adapted to circulate a working fluid between the indoor and outdoor heat exchangers, and an expansion device disposed between the indoor and outdoor heat exchangers. A monitor for the heat-pump system may include a return-air temperature sensor, a supply-air temperature sensor, and a processor. The return-air temperature sensor may be adapted to measure a first air temperature of air upstream of the indoor heat exchanger. The supply-air temperature sensor may be adapted to measure a second air temperature of air downstream of the indoor heat exchanger. The processor may be in communication with the return-air temperature sensor and the supply-air temperature sensor. The processor may be programmed to determine a working-fluid-charge condition of the heat-pump system based on the first and second air temperatures.

The present description discloses a combustion type water heater that heats water by burning fuel. The combustion type water heater includes: a burner that generates combustion gas by burning the fuel; a heat exchanger that exchanges heat between the water passing through on an inside of the heat exchanger and the combustion gas flowing on an outside of the heat exchanger, an exhaust pipe that discharges the combustion gas after the heat exchange in the heat exchanger as exhaust gas; an exhaust gas temperature detector that detects a temperature of the exhaust gas flowing in the exhaust pipe as an exhaust gas temperature; a clog degree detector that detects a degree of clog in the exhaust pipe; and a scale buildup determiner that determines whether or not scale has built up inside the heat exchanger based on the exhaust gas temperature and the degree of clog in the exhaust pipe.

A heating control system including an air circulation fan, a heating unit, a memory, and a microprocessor. The microprocessor is configured to operate the air circulation fan at a first speed and the heating unit in a first configuration to achieve a first temperature rise where less than all of the burners are active. The microprocessor is further configured to compare the first temperature rise to a first temperature rise threshold and transition the air circulation fan to a second speed to achieve a second temperature rise when the first temperature rise is less than the first temperature rise threshold. The microprocessor is further configured to compare the second temperature rise to a second temperature rise threshold and transition the air circulation fan to a third speed when the second temperature rise is greater than the second temperature rise threshold.

A heating control device comprising input/output ports, a memory, and a microprocessor. The microprocessor is configured to transmit a first electrical signal to operate an air circulation fan at a first speed and a heating unit in a first configuration to achieve a first temperature rise where less than all of the burners are active. The microprocessor is further configured to obtain a return air temperature, obtain a room air temperature, and determine a temperature difference between the return air temperature and the room air temperature. The microprocessor is further configured to compare the temperature difference to a temperature rise threshold and transmit a second electrical signal to transition the air circulation fan from the first speed to a second speed to achieve a second temperature rise that is less than the first temperature rise when the temperature difference is greater than the temperature rise threshold.

A process air unit (20) for heating a process air (21) for a workpiece processing system comprises a process air duct (22) through which a process air (21) can flow, a combustion chamber (30) for burning a combustion air, which is overflowed by the process air (21) in the process air duct (22) and thereby transfers heat to the process air (21), and a tube bundle arrangement (35) connected to the combustion chamber, which comprises at least one tube bundle (36) having a plurality of tubes (38) through which the flue gas (34) from the combustion chamber (30) can flow. The plurality of tubes (38) of the at least one tube bundle (36) is oriented in the process air duct (22) transversely to the process air flow direction, so that they are overflowed by the process air (21) and thereby transfer heat from the flue gas (34) to the process air (21), and the tube bundle arrangement (35) is arranged, with respect to the process air flow direction, upstream of the combustion chamber (30) in the process air duct (22) in order to achieve increased energy efficiency.