Heat Interface Units
and Cooling Interface Units

Tried & Trusted

The most important design objective for a 4G Heat Network (HN) is to consistently achieve low return temperatures under all operating conditions.

Achieving consistently low return temperatures requires a complex interaction of several technologies:

  • Control Valves
  • Differential pressure control
  • Temperature control
  • Heat transfer

Best Practice

Danfoss FlatStation Heat Interface Units (HIUs) are highly efficient, easy to install and come in 2 main types: Direct and Indirect. In both, Domestic Hot Water (DHW) is heated via a plate heat exchanger (PHEX) by primary water circulating from either the central plant or heat network. Space heating may be supplied by Direct FlatStations, where the primary circuit connects directly to dwelling space heating circuits.

Alternatively, Indirect FlatStations enable the primary circuit to be kept hydraulically separate from the apartment space heating by using a second plate heat exchanger.

Both arrangements can be adapted to either underfloor heating (UFH) or to radiators.

To ensure the best performance all Danfoss FlatStation HIUs utilise self-acting thermostatic and mechanical controls which along with the plate heat exchangers are sized to achieve a good valve authority and selected for an efficient transfer of heat. Hence, all Danfoss FlatStation HIUs are bespoke to the project requirements.

Also available are Danfoss Cooling Interface Units (CIUs) for indirect cooling enabling the primary circuit to be kept hydraulically separate. These are supplied with fully insulated and vapour sealed enclosures, designed to prevent condensation of the internal valves and pipes. Insulated enclosures means that the Danfoss CIU components can be left uncovered, which makes access for maintenance tasks considerably easier.

All Danfoss CIUs are supplied with the Danfoss Electronic Controller (ECL). The ECL are intelligent temperature regulators for heat networks and communal heating. By means of weather compensation and application keys, they can be adapted to a variety of project specific requirements, ensuring a high level of comfort and optimum energy utilisation.

Alternatively, a direct cooling solution is also available. For more information please see the 4 Series Monolink page.

Key to the ongoing success of a Heat Networks is client satisfaction. Accordingly, all HIUs and CIUs are designed for easy commissioning, low maintenance and a long-life expectancy (low OPEX and REPEX).

HIUs and CIUs Documents

Please see all relevant document categories for HIUs here.

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