45
EXPERT 64+, rev.12
EXPERT 64+
6.4.3. Attic Vent Compensation
When the EXPERT 64+ operates in mini-
mum ventilation and the attic temperature
is warm enough, the controller can extract
the warm air from the attic by increasing the
operating time of the fans. When this com-
pensation is on, the controller automatically
adjusts the
“On Time“
portion of the minimum
ventilation timer as a function of the room
temperature.
If the room temperature is cooler than the
“Attic start comp at”
value and the attic tem-
perature is equal or higher than this start-up
point, the
“On Time”
of the minimum ventila-
tion cycle is fully compensated in order to
extract a maximum level of heat from the
attic (the fans are always on). As the room
temperature rises and reaches the compen-
sation’s start-up point, the
“On Time”
starts
decreasing gradually, in a linear fashion, as
the room temperature increases. The
“On
Time”
finally stops being compensated when
*This compensation only takes place when the at-
tic temperature is warmer than the
“Attic start T°”
temperature value.
Room
T°
Room T° <
Compens.
start T°
Room T° =
Compens.
start T°
Room T° =
Compens.
stop T°
Attic Compensation on
the Minimum
Ventilation Timer*
Compen-
sated
On Time
(On Time=
Cycle Time)
Regular
On Time
On Time of
the Min
Vent.
Timer
the room temperature is warm enough and
reaches the
“Room Stop T°”
value. At the end
of the compensation, the minimum ventilation
“On Time”
goes back to its regular value, and
the sidewall vent starts being used jointly
with the attic vent.
If the room temperature is higher than the
cut-off point of the attic compensation
and then starts decreasing, the
“On Time”
becomes fully compensated when the room
temperature falls to the attic compensation’s
cut-off point
“Room Stop T°”
. The
“On Time”
then starts decreasing gradually, in a linear
fashion, as the room temperature falls. The
“On Time”
finally stops being compensated
when the room temperature reaches the
“Attic
start T°”
value.
The “On Time” can only start decreas-
ing when the “Off Time” portion of the
minimum ventilation cycle is long enough
to allow pre-opening the attic vent.
Refer to section 4.5 to enable the attic probe
and refer to section 4.7.3 to assign this probe
to the desired input of the controller.
Summary of Contents for EXPERT 64 Plus
Page 1: ...EXPERT 64 Temperature Controller User s manual...
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Page 76: ...M 890 00077 rev 12 REV 07...
