Submittal Sheet

7
Although BAC-12xxxx FlexStats do not have a built-
in CO
2
sensor, they still have DCV control sequences
available. When DCV is enabled in these models,
IN9 is assumed to be connected to an external KMC
SAE-10xx CO
2
sensor. BAC-13xxxx/14xxxx FlexStats
also have the external sensor option, and if used, the
highest of the two readings (internal vs. external)
will be used to control DCV sequences. The CO
2
ppm display (when enabled) also shows the highest
of the two levels.
NOTE: The three DCV Conguration graphs
on the left show the DCV component
of the signal to the outside air damper.
Depending on the conditions and the DCV
conguration, the signal to the damper
might be controlled by Minimum Position,
Economizer Loop, or other components.
The maximum of these component values
is used, not the sum of them. (If there is a
Low Limit alarm, however, these signals
are overridden, and the damper is closed.)
NOTE: DCV is only available when using an
AHU, RTU, or HPU application with a
modulating economizer option enabled.
Without that conguration, DCV will
not appear in menus, but the CO
2
ppm
readings will (unless turned o in the User
Interface menu) still show on the lower
right of the display.
The graph below shows an example of how a cool-
ing setpoint and the outside air damper position
could be eciently controlled by a FlexStat’s built-in
combination of schedule, motion sensor (congured
for occupancy standby and occupancy override),
and CO
2
sensor (congured for Advanced DCV).
When using applications with a modulating econo-
mizer option, the three types of Demand Control
Ventilation (DCV) congurations available are:
Basic—Provides simple DCV, modulating the
outside air damper in direct response to the cur-
rent CO
2
level with respect to its setpoint. Basic
DCV is much
more energy
ecient than
no DCV at
all, while
maintain-
ing adequate
IAQ (Indoor
Air Quality).
It is the easi-
est DCV method to congure. However, where
VOCs, radon, or other pollutants become exces-
sive during unoccupied times (with no ventila-
tion), the FlexStat’s Standard or Advanced DCV
conguration is recommended.
Standard—When the BAC-13xxxx seings are
properly congured, this complies with CA Title
24, Section
121(c). This
would also
apply to a
properly
congured
BAC-12xxxx
with a remote
SAE-10xx CO
2
sensor. Stan-
dard DCV, under most conditions, is somewhat
less energy ecient than Basic, but it enhances
IAQ.
Advanced—When the seings are properly
congured, this conguration complies with
CA Title 24,
Section 121(c)
and ASHRAE
Standard
62.1-2007 and
follows guide-
lines by Port-
land Energy
Conservation,
Inc. (PECI).
Although Advanced DCV is the most complex to
congure, it is more energy ecient than Stan-
dard while still optimizing IAQ.
Demand Control Ventilation (DCV)
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CO
2
Setpoint
0%
Space CO
2
CO
2
Maximum
DCV Signal
Component
to OAD
100%
Basic DCV Configuration
CO
2
Base
Outside Air
Damper
Position
Component
CO
2
Setpoint
OA Full
OA Area
0%
Space CO
2
CO
2
Maximum
DCV Signal
Component
to OAD
100%
Standard DCV Configuration
CO
2
Base
Outside Air
Damper
Position
Component
“Basic” Signal
“Standard”
Signal
OA Max
OA Full
OA Area
0%
Space CO
2
CO
2
Maximum
DCV Signal
Component
to OAD*
100%
Advanced DCV Configuration
CO
2
Base
Outside Air
Damper
Position
Component
*Under Normal
Vent Mode operation
(see Vent Mode description)
For more details about DCV conguration and
operation, see the FlexStat Operation Guide and
FlexStat Application Guide.