A heating and hot water supply system is provided and includes at least a distribution unit, a hot water supply heat exchanger and a flow rate adjusting unit. The distribution unit adjusts a distribution ratio capable of handling operations including heating, hot water supply and simultaneous heating and hot water supply operations. When the hot water supply operation starts, first hot water supply control, which adjusting a temperature to a hot water supply set temperature by the flow rate adjusting unit, is performed. After supplying the hot water having the hot water supply set temperature according to the first hot water supply control is maintained for a reference time or longer, transition to second hot water supply control, which a tapping water temperature of the hot water supply heat exchanger is brought close to the hot water supply set temperature, and a mixing amount of clean water reduced, is performed.

A hot water recirculation system for a house or other building causes water to be recirculated to a water heater for reheating until the water is above a set-point temperature at which time the heated water is made available for use at a faucet or other hot water plumbing fixture. Recirculation of hot water takes place only when there is demand for hot water at a hot water plumbing fixture. A flow switching module for use in the hot water recirculation system can selectively direct water supplied to the flow switching module from a water heater either to a hot water plumbing fixture or to return piping for returning the water to the water heater. The flow switching module may be operated manually, automatically, or semi-automatically.

An underfloor heating (UFH) system limits the floor temperature of an environmental entity (for example, a room) by pulsing (pulse modulating) the flow rate through a hydronic emitter (circuit) heating the environmental entity. Once the heated water fills the circuit during time interval T.sub.on, the flow is stopped for a fixed time T.sub.off before allowing the cycle to repeat until a target temperature is reached. The ratio of flow/no flow (T.sub.on/T.sub.off) may be a proportional lower floor temperature compared to a traditional circuit supporting a constant water flow. The UFH system may heat a plurality of rooms, each having different floor temperature limitations. The floor temperatures may be limited differently by pulsing the hydronic emitters (circuits) rooms differently.

A zone controller works with a modulating unit comprising memory storing an instruction set and data related to thermostats, a plurality of duty cycles for a plurality of zones, a plurality of time periods for the plurality of zones, and a maximum zone load. A processor is operative to provide a modulating signal to the modulating unit based on the maximum zone load. The modulating signal determines operation of the modulating boiler and the maximum zone load based on the plurality of duty cycles, time periods, and data related to thermostats. The zone controller may be further operative to: calculate a first duty cycle for the first zone based on a first time period; calculate a second duty cycle for the second zone based on a second time period; and determine a maximum zone load, which is a greater of the first duty cycle and the second duty cycle.

Thermal energy systems for managing, distribution and recovery of thermal energy. A single-pipe loop circulating a two-phase refrigerant is provided. The single-pipe loop is spread through the entire system and interconnects a plurality of local heat exchange stations, each having different thermal energy loads. A central circulation mechanism (CCM) is also provided for circulating the refrigerant for distribution of thermal energy within the system.

An underfloor heating (UFH) system limits the floor temperature of an environmental entity (for example, a room) by pulsing (pulse modulating) the flow rate through a hydronic emitter (circuit) heating the environmental entity. Once the heated water fills the circuit during time interval T.sub.on, the flow is stopped for a fixed time T.sub.off before allowing the cycle to repeat until a target temperature is reached. The ratio of flow/no flow (T.sub.on/T.sub.off) may be a proportional lower floor temperature compared to a traditional circuit supporting a constant water flow. The UFH system may heat a plurality of rooms, each having different floor temperature limitations. The floor temperatures may be limited differently by pulsing the hydronic emitters (circuits) rooms differently.

A conditioning or heating plant and a process of controlling the plant, wherein plant comprises at least one circuit for distributing a carrier fluid, having a delivery line, a return line, and a plurality of channels directly or indirectly connected to the delivery line and return line and configured for supplying respective environments to be conditioned and/or heated, at least one heat treatment central group placed on the circuit. The plant has, for each of the channels, at least one respective heat exchange unit and at least one flow-rate regulator.

A conditioning or heating plant and a process of controlling the plant, wherein plant comprises at least one circuit for distributing a carrier fluid, having a delivery line, a return line, and a plurality of channels directly or indirectly connected to the delivery line and return line and configured for supplying respective environments to be conditioned and/or heated, at least one heat treatment central group placed on the circuit. The plant has, for each of the channels, at least one respective heat exchange unit and at least one flow-rate regulator.

A method for balancing mass flow during production failure or insufficiency in a district heating network comprising a plurality of substations, each substation comprising at least one primary side connected to the district heating network for transferring heat between the district heating network and the substation, a secondary side connected to least one space heating circuit for heating at least one space connected to the substation, and an adjustable valve arranged between the substation and the district heating network, the valve (102) in each substation being controlled by a heat curve f defining a calculated supply temperature (Tsupply, calc) for the space heating circuit on the secondary side of the substation as a function of a measured outdoor temperature (Toutdoor). The method further comprises a step of heat curve compensation for each substation and population compensation for all substations in the population. The result is then used to control the valve in the respective substation.

A heating system comprising an air circulation fan, a heating unit, a memory that is operable to store a temperature map, 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. When the heating unit is in the first configuration, the heating unit is configured to achieve a first temperature and such that less than all of the burners are active. The microprocessor is also configured to receive a temperature set point and to determine a second speed for the air circulation fan using the temperature set point and the temperature map in response to receiving the temperature set point. Further, the microprocessor is configured to transition the air circulation fan from the first speed to the second speed in response to determining the second speed.