INSTALLATION
IMPORTANT: We strongly advise that the unit is commissioned before being installed in a loft.
Prior to installation the loft should be inspected to ensure there is adequate ventilation of the loft. The presence of daylight is a good indication of a
loft that is suitably ventilated. Advice should be obtained if the loft is tightly sealed.
There should be no leaks from the house into the loft. Extractor fans should not discharge straight into the loft, loft hatches and holes for ceiling
lights should be adequately sealed.
The unit must not be installed in a loft space that is open to another property’s loft space e.g. in a terraced home without a barrier between loft spaces.
OPERATION
Unit Setting
The SANO IPIV LOFT unit runs continuously
in your loft at a low level supplying fresh clean
air into your home. This fresh air dilutes the
stale and humid air in your house and is a great
way to prevent and even cure condensation
dampness and mould problems.
The unit setting is selected by the installer to
suit the size, layout, thermal properties and
moisture production in the home. Getting
this setting right is very important and is often
based on the experience of the installer. It is as
important not to over ventilate as it is to under
ventilate a home. The Homevent Residential
team has much experience in setting PIV units
and can be contacted anytime for advice.
The unit has numerous automatic speed
adjustments to optimise ventilation and energy
use.
Normal Mode
The unit will run in this mode for the vast
majority of its time until the unit’s integral
sensors switch it to “ECO-LoFlo”, “Heat
Recovery” or “Comfort Control”, or “Standby”
mode, or the “Override Boost” mode (if
connected via a suitable switch) is activated by
the occupants.
This rate is set via 3 RATE dip switches shown in
the wiring diagram, when leaving the factory
this is set to 29l/s.
Heat Recovery or Comfort Control Mode
When the Heat Recovery mode function
is required, when air in the loft is above the
selected trigger temperature, the unit will
automatically switch to the selected increased
speed. This increase in speed takes advantage
of otherwise unused energy in the roof space
and brings it inside the house potentially
reducing heating bills.
When the Comfort Control mode function
is required, when air in the loft is above the
selected trigger temperature, the unit will
automatically switch to the selected reduced
speed.
This trigger temperature is adjustable between
15-25°C, via THR dip switches (shown in the
wiring diagram). The default when leaving the
factory is 19°C. It is usually adjusted to 1°C
above the temperature the home is heated to.
The amount the fan increases/decreases
is adjustable via the BOOST dip switches
(shown in diagram). The increase/decrease
is adjustable between -50% and +50% of the
Normal mode speed. The factory default is
+20%.
FOR EXAMPLE: The Normal mode speed is set
at 29l/s, BOOST dip switches set to 0111 (+20%
default). When triggered, the increased airflow
will be 29+5.8=34.8l/s.
Summer Standby Mode
The summer shutdown function limits the
chance of the house overheating when
temperatures in the loft reach a level that
is uncomfortable. The unit will essentially
switch off when the loft temperature reaches a
“Standby” trigger temperature to save energy
and prevent undesirable warm air being
introduced unnecessarily in to the home.
Some customers wish to have their unit
operating all year round e.g. for Radon Gas
control or pollen filtration during summer.
That’s why an adjustable trigger temperature
has been incorporated.
This temperature set point is adjustable via TSS
dip switches (shown in the wiring diagram)
between 20°C and 40°C, the default when
leaving the factory is 26°C.
Override Boost Mode
The unit’s automatic controls can be
overridden to operate the unit at its maximum
airflow by means of a user switch.
The override boost can be triggered via a
dedicated external volt free switch connecting
PURGE terminals (shown in diagram). Purge
operation overrides any other speed settings.
This function can be incorporated at
installation stage or later. The unit will function
automatically with or without it.
To prevent excessively warm air being supplied
to the home and to protect the components
of the unit, the purge will not operate above
40°C.
ECO-
LoFlo
Function
The unit constantly monitors the incoming air’s
temperature and moisture content.
When the incoming air is below 10°C the unit
checks its moisture content to see how dry it is
as less drier air is needed to be supplied to the
home to control internal humidity levels. The
unit’s Normal airflow is reduced automatically
in proportion to its moisture content under
this function, however, to ensure minimum
ventilation rates are maintained, a minimum of
50% of Normal airflow is always provided. This
unique control function can not only provide
improved comfort levels for occupants, but can
also significantly reduce the demand on their
heating.
The ECO-LoFlo function is enabled as standard
leaving the factory. It can be manually enabled/
disabled via a switch provided separately
by the installer for use by the occupants if
required, or it can disabled by a link in the unit’s
control box. Please see the control box wiring
diagram.
Hours Run Monitor
The unit keeps track on the unit’s running
hours, and shows this value on the integrated
LCD, placed on the electronic circuit. The value
is not lost in case of power supply failure.Purge
operation overrides any other speed settings.
This function can be incorporated at
installation stage or later. The unit will function
automatically with or without it.
To prevent excessively warm air being supplied
to the home and to protect the components
of the unit, the purge will not operate above
40°C.
