User Manual

www.siemens.com/symaro
Answers for infrastructure.
The worldwide
standard
for home
and building
control
Energy-efficient control strategy
Air quality based demand-controlled ventilation
What is a demand-controlled
ventilation system?
Fixed ventilation systems provide con-
stantly sufficient fresh air for full occu-
pancy. The provided volume of heated or
cooled air therefore does not always match
the actual required one. Scheduled venti-
lation can provide fresh air at the correct
rates at the right time but runs the risk
of under or over ventilation if schedule
changes are not made at the appropriate
times. On the other hand a demand-con-
trolled ventilation system controls the
amount of outside air brought into the
building. It provides just the amount of
outside air the occupants actually need.
In rooms which are not fully
occupied, the outside air flow rate
needs to be reduced to make more
rational use of energy. Demand-
controlled ventilation is the
right energy-efficient solution to
achieve this.
Demand-controlled ventilation
with CO
2
/ VOC* sensors
Demand-controlled ventilation can be
achieved by various means, the most
effective of which is by determining
indoor air quality by the amount of CO
2
.
Further, there may be additional sources
of odors. New furniture, carpeting,
paint, office equipment, smoke, or other
processes may add contaminants that
overwhelm the designed ventilation or
occupants’ perceptions. VOC sensors
will likely detect these unusual odors.
* VOC: Volatile Organic Compound (mixed gas)