An aspect of some embodiments of the current invention relates to an integrated system for heat distribution among a plurality of users. In some embodiments, the system includes a separate automatic control of heat distribution to each user and/or separate billing to each user. For example, a system may supply hot fluid to a plurality of apartments in a building and/or in multiple buildings. Optionally, each apartment has separate remote controlled valves controlling flow of heated fluid to the apartment and/or a sensor sensing how much heat enters and leaves the apartment in the hot fluid. In some embodiments, a processor controls the valve and/or receives data from sensors. The processor optionally controls devices that generate and/or store and/or dissipate heat. Optionally the processor predicts energy availability, costs and needs controls valves and/or devices to provide for predicted and/or unexpected needs while reduce cost of the energy.

A fenestration assembly comprising a sliding glass assembly that slides between a fully closed position and a fully open position in which the sliding glass assembly is received into a pocket of the fenestration assembly. The pocket is covered on at least one side with insulation. The fenestration assembly may have two sliding glass assemblies. The fenestration assembly may be used in an energy efficient building system.

A fenestration assembly comprising a sliding glass assembly that slides between a fully closed position and a fully open position in which the sliding glass assembly is received into a pocket of the fenestration assembly. The pocket is covered on at least one side with insulation. The fenestration assembly may have two sliding glass assemblies. The fenestration assembly may be used in an energy efficient building system.

A heating system of a building includes: a solar heater configured to receive sunlight and to at least one of absorb heat into a refrigerant and augment heat absorbed into the refrigerant; a compressor configured to compress the refrigerant that vaporized via absorption of heat; a first heat exchanger configured to transfer heat from the refrigerant to water; an expansion valve configured to reduce at least one of a temperature and a pressure of the refrigerant after the transfer of heat from the refrigerant to water; a second heat exchanger configured to transfer heat from water output from the first heat exchanger to air passing the second heat exchanger before flowing into the building; a pump configured to pump the water from the solar heater to the second heat exchanger; and a blower configured to blow air past the second heat exchanger and into the building.

A system for regulating a building energy supply and distribution installation, the installation including items of energy collection equipment, each of which is in an energy transfer relationship with a respective source; items of energy transformation equipment powered by the collection equipment; items of energy using equipment; the regulation system configured for defining, for the items of equipment, different respective activation states chosen according to parameters, for optimizing with regard to criteria. The system implements a method in the installation, with the following steps: regulation is performed by placing the items of equipment in respective activation states chosen according to demand and parameters, for the purpose of optimizing with regard to criteria; at an intervention instant of regulation, regulation takes forecasts relating to at least one of the parameters into account, the forecasts relating to a period after the intervention instant. A related installation includes the regulation system.