Cupboard/loft-mounted intake/extract wholehouse ventilation unit with built-in heat recovery facility. It has twin centrifugal motor/impellers which provide balanced supply and extract ventilation with up to 70% heat recovery. In conjunction with the 150VA Transformer the unit has the facility for matching the performance of the unit to the size of dwelling.

Performance of HR250: Up to 61 l/s FID capacity (balanced airflow). Unit extracts the moist and polluted air from kitchens, utility rooms, bathrooms and toilets and replenishes other areas of the dwelling with fresh tempered air. Fitted in a loft area



The HR250 wholehouse ventilation unit is designed for fitting within a kitchen cupboard or in the loft space. 100mm Ø rigid or flexible duct connects the fans spigots to ceiling terminations and to the outside air extract and intake points. When passing through an unheated area insulated ducting should be used.



HR250 to be used with a 150VA Transformer for maximum controllabilty


Motor Speed 1 2 3 4 5 6
Volume l/s (FID) 16 25 31 38 43 61


Weight: 11.5kg

Power Consumption
Speed 1 80V 20W
Speed 2 100V 36W
Speed 3 120V 51W
Speed 4 140V 60W
Speed 5 160V 80W
Speed 6 240V 185W



Typical Specifications

Supply and install a HR250 Wholehouse heat recovery unit as manufactured by:

Vent-Axia Clean Air Systems
Fleming Way
West Sussex
RH10 9YX




Max ventilation rate



N° speed settings


Efficiency: The unit should retain up to 70% of the temperature differential of out going air.

Heat exchanger: should be of a multi plate cross-flow type constructed out of a polymeric plastic with ultra sonic welded joints.

Motor: should be a 240V 50Hz A/C with sleeve bearings, greased for life. It shall operate up to an ambient temperature of 40°C and be fitted with a manual reset thermal overload protective device.

Fan: The fan impeller should be of a forward curved centrifugal type, dynamically balanced.

Controls: The unit should be powered via a remote multi-step transformer that provides a switch gate between a selected slow speed and boost condition. The switch can be a manual or sensor type or a combination of both.

Ducting spigots: The unit should provide 100mm Ø 100mm tapered spigots for all duct connections. The inlet and outlet spigots can be configured to be either left right handed (Can be converted to flat ducting).

Filter: Not fitted as standard. Pollen filters are available. Synthetic material tested to EU3 with 85% arrestance. (Eurovent 4/5 test BS6540).

Stock Ref No: 37 04 97

Condensation: The outlet provided should be 22mm Ø with an option for connection on both sides of the unit dependant on spigot configuration. (Can be converted to flat ducting).

Construction: The unit outer case and fan volutes should be moulded from black MDPE.

Mounting: Horizontal or Vertical

Sound Levels: dB(A) @ 3m


​Speed 1: ​20
​Speed 2: ​25
​Speed 3: ​30
​Spped 4: ​35
​Speed 5: ​39
​Speed 6: ​48


Mains electrical supply: 230VAC 50Hz.

Complies to the following approvals/directives: CE.








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