Safety First
The Heat Recovery Ventilator is a “SELV” (Safety Extra Low Voltage) ventilator that
operates at 12 volts AC. Under no circumstances must this be connected directly to the
mains supply. Damage so caused is not covered by the warranty. The isolating transformer
/ humidity sensor supplied must provide the low voltage used by the ventilator. A typical
layout of installation is shown above.
The Heat Recovery Ventilator can be used in any room that has an outside wall open to fresh
air. It is particularly useful in the bathroom, kitchen or laundry room where high levels of
moisture are generated. It can also be used in the lounge, dining room or any bedroom to
provide a fresh air supply to reduce dust-mite, eliminate mould growth or dampness and
condensation and to provide warmed fresh air.
Isolating Transformer (Humidity sensor unit)
The humidistat monitors the humidity in the room and automatically switches the ventilator
from continuous trickle speed to boost if the humidity exceeds the set point e.g. when using
the shower, cooking or doing the laundry.
The humidity level setting can be adjusted by turning the thumbwheel (as shown on page
2). We recommend that it is initially set to 50% - 55% which is suitable for most locations.
Turning the thumbwheel clockwise towards 90 decreases the sensitivity (fan in boost for
shorter time) and anticlockwise towards 20 increases the sensitivity (fan in boost for longer
time) and is marked in 10% stages.
To prevent tampering with the setting after installation, the thumbwheel can be removed by
carefully pulling upwards. A blanking plate is supplied to seal the hole previously occupied
by the thumbwheel.
If installed in a shower or bathroom the transformer / humidistat must be out of reach of
anyone using a bath or shower. This unit must be installed by a competent electrician.
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