Third party certification
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HIU - Heat interface unit
Certification manual
Certification Manual
Documents
OM (Operational Manual)
RS (Rating Standard)

Scope of the programme

The present certification scheme covers Heat Interface Units, defined as a packaged unit including at least one Domestic Hot Water heat exchanger and control elements.

The HIU may contain:

  • An additional heat exchanger for heating
  • Balancing elements
  • 1 heating pump
  • Metering possibilities

The HIU covered by the scheme are 3 pipes configurations. HIU with DHW capacity level above 70 kW are not covered by the certification scope. Only units for single family dwellings use are covered.

The covered technologies are:

  • Domestic Hot Water technology only: HIU/DHW
HIU-DHW
  • DHW and direct heating technology: HIU/DHW/DH 
HIU DHW DH
  • DHW and direct heating mixed technology: HIU/DHW/DHM
HIU DHW DHM
  • DHW and indirect heating application: HIU/DHW/IH 
HIU DHW IH

 

Symbol

Signification

Heat Pump

Pump

Heat Exchanger

 

Heat Exchanger

Mixing valve

Mixing valve

 

Definitions

Heat Interface Unit

Packaged unit including one or more heat exchangers, control elements transferring heat from a primary to a secondary system. The primary system may be a district or communal heating scheme. The secondary system is the space heating or domestic hot water system within the dwelling of other space.

Direct Heating

Primary system and secondary system for space heating are directly connected through the HIU without any heat exchanger. Primary and secondary system are supplied with the same water and pressure. Space heating temperature flow isn’t controlled by mixing loop.

Direct Heating Mixed

Primary system and secondary system for space heating are directly connected through the HIU without any heat exchanger. Primary and secondary system are supplied with the same water and pressure. Space heating temperature flow is controlled by a mixing loop.

Indirect Heating

Primary system and secondary system for space heating are indirectly connected through the HIU with a heat exchanger separating both systems. Primary and secondary system are not supplied with the same water and pressure.

Certified performances

The following performance data declared by the applicant/participant are verified by tests:

Certified Performances

Unit

Technology type concerned

Maximal DHW capacity

kW

All 4 technologies

Return temperature during normal DHW tapping

°C

Minimal DHW flow rate

l/min

>DHW reaction time

>s

DHW Standby heat losses

kW

Capacity on temperature delta of 20 K

>kW

DH

Capacity on temperature delta of 10 K

kW

>DHM

Difference between primary return temperature and secondary return temperature at 4kW

°C

>IH

Heat losses

kW

DH, DHM, IH