Lo-Carbon HR25



The through the wall Lo-Carbon HR25 range provides a low voltage solution for wet rooms and comes with 3 control options: pullcord, PIR and humidity versions, and available in two lengths. The units offer the latest technology featuring 84% heat recovery and easy, core drill installation. The 2-speed units are fitted with a 24V LoWatt Energy Saving DC motor with state of the art switch mode power supply.These units have the ability to operate at a power consumption of under 2 Watts running at trickle speed. A 5m cable is provided for fixed wiring the unit to the S.M.P.S. Requiring only 152mm core drill, the units are suitable for walls from 310mm up to 425mm thick.

Two speed performance: Low 20m³/h and High 55m³/h. For use in bathrooms and WC’s.


Typical Installation

HR25 Typical Installation 

The Lo-Carbon HR25 unit is designed for installation in a 152mm (6") core drilled hole. All installations can be carried out from inside the building. The standard units are suitable for external walls up to 310mm thick. For thicker walls extended models are available, suitable for walls up to 425mm thick.



Apart from removing odours, providing fresh air and recovering heat, this appliance extracts airborne impurities such as dust, dirt and grease. These gradually build up and detract from the efficiency and appearance of the appliance. Therefore to ensure peak performance, the appliance should be cleaned regularly. Filters should be replaced every six months or as conditions necessitate. The heat exchanger and grille should be washed in warm soapy water every twelve months or as conditions necessitate.


Power Consumption

 Normal    1.9W  
 Boost    25.1W


A B C D E F Weight
Standard 508 451 318 147 204 54 3.4
Long 666 548 433 147 204 54 3.4



Typical Specifications

Supply and install a Lo-Carbon HR25 single room through the wall heat recovery unit as manufactured by:

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

Performance: m³/h l/s
Max ventilation rate 54.8 15.2
Normal Supply Rate 7.8 2.1
Normal Extract Rate 15.7 4.3
Boost Supply Rate 35.7 9.9
Boost Extract Rate 54.8 15.2
N° speed settings 2

Efficiency: The unit should retain up to 84% of the temperature differential of out going air.

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

Motor: Should be 24V DC with sleeve bearings, greased for life. The motor shall operate up to an ambient temperature of 40°C and be fitted with a thermal overload protective device.

Fan: Impeller should be a polymeric centrifugal backward curved type. Configured as a split single wheel.

Controls: The unit should be operated via integral pull cord switch, PIR or humidistat.

Filter: Should be a reticulated foam type coarse filter.

Condensation : The outlet should be via drain holes in the lower part of the external grille.

Construction: The unit outer case should be terracotta coloured extruded ABS wall tube with black EPDM wall seals and terminating in a weather cowl. The internal grille should be white ABS.

Sound Levels: dB(A) @ 3m
Trickle: 16.8
Boost: 49.2

Mains electrical supply: 230VAC 50Hz.

24V dc Power supply: should be derived from a switch mode type device (S.M.P.S.).

Complies to the following approvals/directives: LVD, EMC and EN60335-1.


There are no softwares available for download for this particular product.