Indirect Danfoss FlatStation HIUs
In the case of Indirect Danfoss FlatStation HIUs, the primary circuit from the central plant room is made hydraulically separate from the apartment space heating by a plate heat exchanger. This maximises the options available to the building operator in terms of circuit working temperatures. Underfloor heating (UFH) systems for example, require lower temperatures than radiator circuits. SAV Systems can supply everything necessary to serve the apartment ‘sealed system’ heating needs, such as a circulator, strainer and expansion vessel.
Indirect FlatStation HIUs also provide Domestic Hot Water (DHW)
Where standing storage is specified, SAV offer the Indirect Danfoss Heat Interface Units FlatStation 3 Series. This has Domestic Hot Water terminal points left available for connection to a DHW storage cylinder.
For installations where Domestic Hot Water is generated on demand, the Indirect Danfoss FlatStation HIU 7 Series comes into its own as it includes 2 separate plate heat exchangers. The Domestic Hot Water at the taps has a closely controlled temperature, and the heating circuits come with integral circulator. Although the equipment inventory is substantial, the Danfoss HIU design has nevertheless managed to accommodate all of this in a well-designed casing.
Space heating controls can readily be accommodated. Signals from room temperature thermostats are routed to the zone valve (enabling isolation of the complete heating circuit) and to the circuit thermostatic valve (enabling modulation to maintain desired value).
Good valve authority is required if the thermostatic controller is to maintain comfortable conditions at all times.
An auxiliary pressure controller across the thermostatic valve ensures this every time.