Operating Manual
“Warm N Dry”
www.hvsolutions.com.au
6 of 12
Copyright 2010
Control Panel
The thermostat displays the roof space temperature at all times accurate to 0.1 degree celsius
and has two programmable set points (SP1 and SP2):
SP1 is the setting at which the unit switches from Ventilation mode to Heat Recover
mode (typically set at 18 degrees).
SP2 is the temperature at which the unit switches off completely when it is too cold for
ventilation to be effective (typically 5 degrees).
Both set points can be changed by pressing the P button for 1 second and raising or lowering the
settings with the arrow keys. The settings should be selected depending on the house
requirements i.e. degree of condensation, fresh air requirements and free heat recovery or
varying degrees of each. If you are unsure of the best setting, please contact HVS for advice and
or check the Technical section later in this document.
In addition to SP1 and SP2, there are two switches that turn the Ventilation and Heat Recovery
modes on or off and a variable fan speed control.
The variable fan speed dial controls the amount of air transferred during the ventilation mode
which is the temperature range between SP1 and SP2. It can be manually varied between 30%
and 100% of the fans air flow capacity (min to max on the dial). When the roof temperate is
above the SP1 value, the variable fan speed control is bypassed and the fan runs at 100% if the
Heat switch is on otherwise the fan will turn off if the Heat switch is in the off position.
The correct setting for the variable fan speed controller is the minimum airflow setting that clears
the condensation from windows and or provides the desired air quality. Experimentation with the
variable speed setting is required because it will depend on a how bad the condensation problem
is and the house size. Too high a setting could result in the house becoming cold during the
night, too low will prevent the system from providing adequate ventilation.
Modes of operation
Variable
fan
position
SP1
range
SP2
range
Fan
Switch
Heat
Switch
System OFF
Off
Off
Heat recovery mode only
.
(Fan operates at
100% when the roof space temperature is >
SP1)
17
– 22
Off
On
Automatic Climate Control
.
(Fan operates
at the variable speed setting when the roof
space temperature is > SP2 and < SP1. Fan
operates at 100% when > SP1)
0
– 50% 17 – 22 3 – 10
On
On
