A local energy distributing system includes a local feed conduit; a local return conduit; a central heat exchanger connected to a heating grid having a feed conduit for an incoming flow of heat transfer fluid having a first temperature in the range of 50-120° C., and a return conduit for a return flow of heat transfer fluid having a second temperature, the second temperature being lower than the first temperature, wherein the central heat exchanger is configured to exchange heat from the incoming flow of heat transfer fluid to an outgoing flow of local heat transfer fluid in the local feed conduit. The system also includes a plurality of local heating systems, each having an inlet connected to the local feed conduit and an outlet connected to the local return conduit, wherein each local heating system is configured to provide hot water and/or comfort heating to a building.

The invention relates to an HVAC apparatus, method, and system. Aspects of the invention include a supplemental heat source with an air handler unit for a conventional forced air heating and cooling system. The supplemental heat source in one example is a hydronic subsystem. It can be used alone or to supplement the forced air subsystem. Another aspect of the invention includes an air handling subsystem that has a housing that can be highly flexible in configuration and installation. The housing can support internal components, including a hydronic or other supplemental heat source with the forced air components. At least two sides of the housing can be configured for access for maintenance and repair. A control system can be designed to eliminate need for defrost cycle for forced air refrigeration-type subsystem and/or for better maintenance for comfort in the air conditioned space.

A water heating system for a domestic hot water tank, the system including: a heat pump adapted to provide heat energy; and a heat exchanger comprising a coil of thermally conductive material arranged such that a diameter of the coil is approximately between five and six times greater than a diameter of the thermally conductive material and the heat exchanger is adapted to be installed in the domestic hot water tank and operationally coupled to the heat pump.

A method for controlling a distribution temperature of domestic hot water implemented in a management unit of an installation for producing domestic hot water and including steps for obtaining mean temperatures of the distributed hot water, determined by time ranges and measured by one or more divisional distribution meters in the course of a reference period; obtaining a minimum value and a maximum value of these temperature averages in order to determine a temperature condition of the distributed hot water from at least the maximum value or the minimum value, and from at least one predefined temperature threshold, and, if the distribution condition determined is met, sending a sequence controlling the production temperature to the production installation. Also, a distribution installation, a distribution meter and a unit for managing the distribution of domestic hot water.

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.

A multi-temperature output fluid heating system including an input for receiving a fluid supply, a single heating source, a first output, a second output and a bypass path. The first output is fluidly connected to the input, where the first output is adapted for control by a first control device and to receive heat from the single heating source to achieve a first temperature at the first output. The bypass path fluidly connects the input and the second output. The input is adapted to empty a first portion of the fluid supply into the first output and a second portion of the input into the bypass path. The second output is adapted to receive an output from the first output and an output from the bypass path to achieve a second temperature.

Systems and methods for solar fluid heating in a multi-story building. A system in accordance with an aspect of the present disclosure includes solar collectors installed in solar-facing walls of the multi-story building, in which fluid receives thermal energy from the solar collectors. The system also includes fluid storage vessels. The system further includes a circulating pump coupled to the solar collectors to circulate the heated fluid between the solar collectors and the fluid storage vessels on a floor of the multi-story building.

A system and method that optimizes energy consumption in an HVAC unit by minimizing chiller activity. The system uses a control unit that overrides a thermostat in at least one room to close a cooling valve that leads a fluid input to the room. When multiple cooling valves are closed through the rooms, the consequential return fluid maintains greater cooling capacity and thus, the chiller does not have to operate at full capacity. The control unit individually controls components in the HVAC unit, which were previously controlled by switches on the thermostat. The control unit includes a temperature sensor that monitors an environment, such as the room and a plenum. The control unit also includes a control relay that closes the cooling valve on the HVAC unit when the predetermined temperature of the control unit is above the thermostat temperature set by a room occupant.

Embodiments relate to heat exchanger contamination monitoring in an air conditioning system. An aspect includes receiving, by a contamination monitoring logic from a primary heat exchanger outlet temperature sensor, a first temperature comprising an air temperature at an outlet of a primary heat exchanger. Another aspect includes receiving, from a secondary heat exchanger outlet temperature sensor, a second temperature comprising an air temperature at an outlet of a secondary heat exchanger. Another aspect includes receiving, from a compressor outlet temperature sensor, a third temperature comprising an air temperature at an outlet of a compressor. Another aspect includes determining, based on the first, second, and third temperature, a heat exchanger contamination value. Another aspect includes comparing the heat exchanger contamination value to a predetermined contamination threshold. Another aspect includes based on the heat exchanger contamination value being greater than the predetermined contamination threshold, sending a maintenance warning.

A multi-split system and a medium-pressure controlling method thereof are provided. The multi-split system includes an outdoor unit, a distribution device, and a plurality of indoor units. The distribution device includes a gas-liquid separator, a first heat exchange assembly, a first electronic expansion valve, a second heat exchange assembly and a second electronic expansion valve. The distribution device is configured to perform a routine correction on a medium-pressure control target value of the first electronic expansion valve according to the subcooling degree of the heating indoor unit, the outlet air temperature of the heating indoor unit and the opening of the throttling element in the heating indoor unit, and to correct a current medium-pressure control target value of the first electronic expansion valve according to a preset step when the opening of the throttling element reaches a maximum opening or a minimum opening and lasts for a first preset time.