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HRFL II - Ceiling Void Unit

HRFL II 0.03m³/s (108m³/h) – 0.52m³/s (1872m³/h)

Mechanical Ventilation Heat Recovery Unit - Ceiling Void Unit

Applications: Commercial | School / University | Retail | Office Buildings | Hotels | Banking | Leisure

HRFL II - Energy Saving System - Swirl Chamber System - Plug & Play - Near Silent Operation

HRFL II is a next generation, all-in-one, mechanical heat recovery and ventilation system. Especially designed for false ceiling installation, the HRFL II is a fully packaged solution which benefits from a compact, slim design
to suit the increasingly stringent requirements for local ventilation systems installed in ceiling voids.

Highly efficient, with near silent operation, the HRFL II range is equipped with state-of-the-art plug and play integrated controls.

Choose your model
  • 4 models covering airflows from 0.03m³/s (108m³/h) – 0.52m³/s (1872m³/h) @ 200pa ESP

    • HRFL part of the Barkell Air Handling Unit Therm-X MVHR Heat Recovery Range
    • Ecodesign Compliant - HRFL part of the Barkell Air Handling Unit Therm-X MVHR Heat Recovery Range


HRFL II is manufactured with a solid, self-supporting, galvanised frameless. The unit has a powder painted underside for exposed installation and 30mm double skinned, corrosion resistant panels (88kg/m³ RW). The panels are joined with internally enclosed, self-screwing fixings.

The result of this construction is a smooth, crevice free, easy to clean interior surfaces and therefore the cleanliness, and quality of air supplied through it. The base panels have an powder paint finish allowing exposed installation. Fixed and access panels have a high tightness, VDI622 compliant, EPDM closed cell gasket seal, to avoid external leakage.


HRFL II is suitable for internal installation by suspension on the false ceiling. The unit is provided with pre-fitted support brackets with AV mounts and an externally mounted control panel.

Access and maintenance

Access to all the unit compartments is available through the bottom tool operated access panels as standard. All access panels are equipped with hinges and handles to facilitate handling during maintenance operations.

All the panels are fully removable allowing access to the plate heat exchanger, drain tray, fan, filter and ancillary coil sections and facilitating access for periodic inspection. The control panel is easily accessible within an enclosure on the outside of the unit.

Heat recovery
  • Highly efficient counter plate heat exchanger exceeding the 2018 ErP requirements
  • Operational efficiency up to 93%
  • Eurovent certified performance and tested to EN308:1997
  • Manufactured from high thermal transmittance and corrosion resistant aluminium
  • Minimal internal leakage ensured by the double sided inner seals
  • Integrated multi-step anti-freeze logic
  • Single inlet backwards curved radial fans
  • Energy efficient IE4 electronically commutated (EC) motors with integrated electronic control and silent operation
  • Optimised impellers balanced to DIN / ISO 1940
  • ErP ready
  • Integrated control electronics – soft start, over temperature and short circuit protection
  • Motor insulation class ‘B’, rated IP 54 (acc. To EN 60529)
  • VDI6022 compliant plastic frame panel filters
  • Synthetic media filters for low-pressure drop reducing overall unit energy consumption
  • Filtration grade according to BS EN 779:2012/ISO 16890 is F7 (ePM2.5 50%) supply filter and M5 (ePM10 50%) return filter. F9 (ePM2.5 80%) supply filter is available as an option.
  • Filter status monitored by integrated digital pressure sensors
  • Installed in slides and sealed for easy replacement and minimised bypass leakage
Controls & communication

HRFL II features state of the art plug and play integrated controls with a full RGB touch screen multi-colour remote controller. The interface for BMS connection is via Modbus RTU & Modbus TCP.

The intelligent, inbuilt controls include (not an extensive list):

  • Integrated temperature and pressure sensors
  • CAV (Constant Air Volume)
  • VAV (Variable Air Volume) – Constant Pressure Supply
  • DCV (Demand Controlled Ventilation)
  • Trickle & Boost mode
  • Time scheduling
  • Airflow offset
  • Supply and room air temperature control
  • Automatic free-cooling regime
  • Modulation of bypass and up to 2 pre-heaters and post-heaters/coolers
  • Overheat, condensate overflow and frost protection
  • Automatic calibration of fans and filters
  • Service, maintenance and error alarms
  • Soft start
  • Fire interlock
  • PID tuning
Optional features

The  following options, if selected, are all fully integrated into the unit controls:

  • Integrated electrical pre-heater
  • Integrated electrical post heater
  • Integrated LPHW post heater
  • External modular pre and post heater/cooler:
        1. WCO (Water changeover)
        2. DX (Direct Expansion)

There is also an extensive range of ancillaries for enhanced control and facilitated installation.


Vast range of ancillaries available for the HRFL II range:­ 

  • Shut off dampers (rectangular or circular)­ 
  • Square to round transitions­
  • Threaded rods­
  • Duct mounted attenuators­
  • Spare filters­
  • Duct mounted electrical or water heaters­
  • Condensate pump kit­
  • Condensate syphon­
  • Damper actuators­
  • Duct and room mounted IAQ sensors (CO2, humidity)­
  • PIR motion sensor­
  • Valve and actuator kits

Tested for your complete peace of mind
  • Performance – ISO 5801:2007
  • Acoustics – BS EN 3744:2010, BS EN ISO 5136:2010
  • Heat Recovery – EN 308:1997
Building regulations and eco-design directive

All models are performance tested, and measurements are made to obtain the power consumption of the units in several operating points. The units can work within the limits of both of these regulations under most conditions. Detailed software selection can be provided to get accurate performance data.

Download the Therm-X Sales Brochure

Download the Therm-X HRFL II Technical Manual

Please contact us to request the IOM manual, installation guidelines, controls manual or safe operation manual.

Make an Enquiry

If you wish to enquire about this product or have a forthcoming air conditioning requirement, please complete the form below and one of our experienced team will be in touch to address your query. (We always try to respond within 24 hours, excluding weekends and bank holidays).

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