Frese's AquaHeat twin plate heat interface unit (HIU) is designed for the generation of instantaneous domestic hot water and the supply of indirect space heating. This HIU provides hydraulic separation between the domestic hot water and the space heating circuits and the primary heat network via a pair of stainless steel copper brazed plate heat exchangers.
The HIU is available with top or bottom secondary heating connections suitable for radiator or underfloor heating and is complete with an electronic controller for precise and efficient water temperature control and MODBUS communication.
- The electronic HIU controller makes it possible to deliver water at the correct temperature, even in the event of lower supply temperatures and pressures on the primary heating system.
- Very fast reaction time with accurate temperature control when there is a demand for DHW based on the feed forward principle.
- Insulated cover minimises heat loss from the unit.
- Features two pressure independant control valves with fast-acting stepper motors.
- Advanced programmable electronic controller providing:
- 100% hot water priority within 10 seconds
- anti-legionella programme
- Compact and lightweight design for easy handling.
- DHW and indirect heating control.
- 100% priority on DHW tapping.
- No moving parts in DHW circuit (low pressure drop).
- Adjustable or disabled idle temperature function.
Features and benefits
- Compact design.
- DHW programmable electronic controller.
- Programmable DHW temperature range.
- Prepared for thermostat or weather compensator control.
- Compact brazed plate stainless steel heat exchangers.
- 8 litre expansion vessel.
- Programmable heating supply temperature range.
- Very low standby losses.
- EPP polypropylene cover.
- Direct volt-free or Opentherm connection to controller for programmable room thermostat (not included).
- Frese OPTIMA Compact pressure independant control valves:
- adjustable DHW and heating design flow
- +/- 2K hot water temperature control
- Flushing bypass assembly complete with P/T plugs.
- Ultrasonic MID heat meter.
- DHW recirculation pump.
- Modbus I/O communication from HIU controller.