Space heating circuits

Storage combination boiler or storage combi boiler A boiler with an internal hot water tank with an overall volume greater or equal to 15 liters but less than 70 liters. It is a combi boiler with an internal hot water storage of at least 70 liters, where the space heating circuit is not taken directly from the storage. 

Combined primary storage unit (CPSU) The unit is designed to provide both space heating water and the domestic hot water, a burner heats a thermal store that contains the primary water, which is also the space heating circuit water. The store must have a volume of at least 70 liters and the water in the storage is used directly to space heating circuit. 

At its simplest, a HW heating cycle is the circulation of HW from a boiler (or heat pump or similar device) through a supply and distribution piping system to various appliances and then back to the boiler. Hot water systems are hydronic systems and, when of any size, are designed to operate via various primary and secondary circuits. These circuits are provided with their own circulating pumps of different capacities to provide proper layout flow, usually to perimeter-wall m-tube convectors, fan coil units, or other space heating equipment. 

Space heating and hot water supply A similar system to the one discussed above may be used to blow hot air into the foundry hall for space heating. Alternatively, a water-water heat-exchange is used to heat a water circuit for radiators or for hot water supply. 

FIGURE 10 Three ways of coupling an auxiliary heater with the solar space heating system (1) In the storage tank, (2) in the distribution circuit flow pipe (series connection), and (3) In a storage bypass (parallel connection). 

A block diagram is a very simple diagram in which the various items or pieces of equipment are represented by a square or rectangular box. The purpose of the block diagram is to show how the components of the circuit relate to each other and, therefore, the individual circuit connections are not shown. Figure 3.85 shows the block diagram of a space-heating control system. 

Rgure 3.91 Circuit diagram - space-heating control system (Honey Well Y, Plan). 

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