Apparatus and methods for a gas furnace are disclosed. The gas furnace includes a variable combustion control which monitors the temperature of the burner and modifies one of the amount of combustion air supplied and the amount of gas fuel supplied to the mixing chamber. The described systems can dynamically accommodate differences in air quality and gas fuel supply to provide an optimum BTU output irrespective of differences in geographic location of usage. The gas furnace can include a dynamic response unit which predicts an optimum rate of heating to maintain a target room temperature, thereby preventing unnecessary shut down and costly re-ignition sequences, and maintaining the gas furnace at an optimum BTU output level.

Apparatus and methods for a gas furnace are disclosed. The gas furnace includes a variable combustion control which monitors the temperature of the burner and modifies one of the amount of combustion air supplied and the amount of gas fuel supplied to the mixing chamber. The described systems can dynamically accommodate differences in air quality and gas fuel supply to provide an optimum BTU output irrespective of differences in geographic location of usage. The gas furnace can include a dynamic response unit which predicts an optimum rate of heating to maintain a target room temperature, thereby preventing unnecessary shut down and costly re-ignition sequences, and maintaining the gas furnace at an optimum BTU output level.

A water heater may include a water tank, a burner, a pilot for igniting the burner, an ignitor for igniting the pilot, a thermoelectric device in thermal communication with a flame of the pilot, a controller for controlling an ignition sequence of the pilot using the ignitor, and a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device. The controller is configured to selectively run only the pilot for at least part of a heating cycle to increase the recharge time of the rechargeable power storage device while still heating the water in the water heater.

A water heater may include a water tank, a burner, a pilot for igniting the burner, an ignitor for igniting the pilot, a thermoelectric device in thermal communication with a flame of the pilot, a controller for controlling an ignition sequence of the pilot using the ignitor, and a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device. The controller is configured to selectively run only the pilot for at least part of a heating cycle to increase the recharge time of the rechargeable power storage device while still heating the water in the water heater.

A combined heat and power plant includes a gasifier, a heat exchanger arranged to reduce the temperature of the raw synthesis gas formed in the gasifier by exchanging the heat of the raw synthesis gas into heating medium used for heating and forming cooled raw synthesis gas, a filtration unit for cleaning the cooled raw synthesis gas to form refined synthesis gas suitable as a fuel for an internal combustion engine, an internal combustion engine where the refined synthesis gas is burnt to produce mechanical power, ducts for connecting different parts of the plant to each other a raw gas burner arranged after the gasifier to burn the raw synthesis gas formed in the gasifier during the time when the refined synthesis gas is not utilized in the internal combustion engine. A method for treating raw synthesis gas a combined heat and power plant is also disclosed.

Provided is a cogeneration system that includes a plurality of fuel cell devices capable of supplying heat and power to a heat load and a power load and a control device connected to the fuel cell devices. The control device determines an operation mode on the basis of at least one of a heat demand value and a power demand value. The control device controls a power generation efficiency and a heat recovery efficiency by controlling the fuel cell devices on the basis of the operation mode determined.

A heater is described. The heater includes a fuel cell to produce heated air, electricity and water vapor. The heater further includes a heating element operatively coupled to the fuel cell to convert the electricity to heat and a control system operatively coupled to the fuel cell and the heating element, the control system being configured to monitor and control the fuel cell and heating element.

The invention relates to a method of controlling an energy supply system comprising at least two energy generators each configured to provide at least one form of energy of heat and/or cold and/or electrical energy. The energy supply system further comprises one closed-loop controller per energy generator for controlling the energy generator and a control device coordinatedly controlling the closed-loop controllers. The control device detects an energy supply request for providing energy in the form of heat and/or cold and/or electrical energy and determines for each energy form which energy generators are required to meet the energy supply request. For each energy form, the control device generates switch-on requests for the energy generators required to meet the energy supply system and switch-off requests for the energy generators not required. For each energy generator, the control device determines if one, several or no switch-off request is present and if one, several or no switch-off request is present. For each energy generator for which there is at least one switch-on request present, a switch-on request is output to the corresponding closed-loop controller and, for each energy generator for which there is no switch-on request and at least one switch-off request present, a switch-off request is output to the corresponding closed-loop controller.

A hot-water supply system heats up water by power generated by power generation means. The hot water supply system includes a compressor and a water heat-up unit. In the hot-water supply system, the compressor compresses refrigerant and circulates the refrigerant through a refrigerant circuit. The water heat-up unit heats up water by changing, in accordance with the generated power, a rotation rate of an electric motor for driving the compressor.

A liquid heating appliance for heating water or other liquids, suitably to a target temperature of from 55 C. to around boiling point, includes a primary heat chamber or body (heat source chamber) that is thermally insulated and which in use contains a high thermal density heat storing liquid or solid; and a secondary chamber alongside the primary chamber through which a liquid to be heated is passed in use. The appliance has a heat transfer feature to selectively transfer thermal energy from the heat-storing liquid or solid to the liquid to be heated in the secondary chamber. The secondary chamber is preferably a conduit through which the liquid to be heated is able to flow and the thus heated liquid can be delivered to a tap as hot water for a range of uses. Water may also be heated for a central heating system for space heating.