A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device that performs indoor heating and configured to detect a temperature of fluid flowing through the heating pipes, an outdoor heat exchanger configured to perform heat exchange between outdoor air and a refrigerant, a third temperature sensor configured to detect a temperature of the outdoor heat exchanger, and a controller. The controller may be configured to: control power to a boiler and/or to the compressor based on sensing values of the first, second, and third temperature sensors, calculate an expected efficiency of the heat pump based on the sensing value of the first temperature sensor and an initial target temperature, and control power to the boiler based on the expected efficiency.

A waste heat recovery device with a first heat medium side inlet; a first heat medium side outlet; a first heat medium flow path; a second heat medium side inlet; a second heat medium side outlet; a second heat medium flow path; a heat exchanger that exchanges heat between the first heat medium and second heat medium; an expansion tank in the first heat medium flow path; a bypass flow path that causes the first heat medium to flow and bypass the heat exchanger; and a mixer where the bypass flow path and first heat medium flow path merge together. The mixer is configured to adjust a ratio of a flow rate of the first heat medium in the bypass flow path and a flow rate of the first heat medium in the heat exchanger, such that the temperature of the first heat medium after merging approaches a predetermined temperature.

Thermal targeting technology is used to continuously adjust boiler target temperature to the minimum necessary to satisfy the required heating load. Responsive to and initiated by a first call for heat, boiler target temperature is reduced by a predetermined amount upon or subsequent to the call for heat. Once the boiler temperature reaches this new target, a call timer is activated. If demand for heat is satisfied before a time set point is reached, the system ceases providing additional heat energy until the next heat demand. Responsive to and initiated by a next call for heat, the boiler target temperature is again reduced by the predetermined amount upon or subsequent to this next call for heat. Each time the heat demand is satisfied within the predetermined time interval, the boiler target temperature is reduced. If heat demand is not satisfied, a thermal boost is provided at set time intervals until the call for heat is removed.

A water heater includes a storage tank, a sensor configured to measure a temperature of water in the storage tank, a burner configured to heat the water in the storage tank, and a controller communicatively coupled to the sensor and the burner. The controller is configured to initiate a call for heat when the measured temperature reaches a trigger temperature, wherein the trigger temperature is a differential amount less than a set-point temperature, calculate a reduced activation time when the call for heat results in a predetermined number of calls for heat occurring within a predetermined time period, and control the burner based on the reduced activation time.

Embodiments described herein generally relate to a domestic hot water (DHW) preheater operable to supply domestic hot water to a structure and/or to preheat a cold return of a space heating system.

The invention relates to a method for preparing a hydrocarbon by reducing CO.sub.2, wherein CO.sub.2 is reduced to a hydrocarbon with the aid of a directly heated electrode. A device for carrying out a corresponding method, a corresponding power plant and a system comprising said power plant and a vehicle with a combustion engine are also objects of the invention. The method and device may, e.g., be used as a micro-energy system for decentralized energy supply.

A system and method for controlling a boiler comprising a microcomputer operatively connected to a microcontroller wherein the microcontroller is configured to provide flame safeguard operations and the microcomputer is configured to provide operating control instructions to the microcontroller. The boiler control system may operate either in a stand-alone, cascade master or cascade slave configuration.

A combined hot water and air heating and conditioning system including a first heat exchanger, a heat pump, a chilling tower loop, a burner and a second heat exchanger to provide hot water, air heating and air cooling. The system provides hot water, air heating and cooling all in one single unit. The system utilizes a heat pump to remove heat from ambient air and transfer the rejected heat into a hot water system, thereby using waste heat to heat the hot water system. The system utilizes a heat exchanger not only for the purpose of transferring heat from a heating source to a fluid in the heat exchanger but also for the purpose of dissipating heat from the fluid in the heat exchanger to the surroundings of the heat exchanger, thereby allowing a heat pump to act both as an air heating and conditioning device.

A boiler unit (100) housed in an enclosure, the boiler unit (100) configured to receive a solid state combined heat and power generating device (130). The boiler unit (100) comprises a heating device (110) to produce heat; and a control unit (120) to independently control each of the heating device (110) and the solid state combined heat and power generating device (130). The boiler unit (100) is operable without the solid state combined heat and power generating device (130) being present.

A demand based control for a hydronic heating system varies the heat response based on an actual demand of the conditioned space, rather than an estimated thermal loss. Differences between supply and return of a heat transfer medium, such as forced hot water, are measured for the conditioned space, as well as the flow rate of the forced water to determine an actual thermal transfer to the conditioned space. A required heat generation is computed based on the measured transfer and resultant temperature change of the conditioned space, and heat generation parameters such as boiler firing rate and circulator pump speed varied to control the heat transfer to the conditioned space and avoid overshoot or excessive heat generation beyond that needed for the measured demand.