Rev. d 01/1 42
DMP052E
EXAMPLE 7:
RETURN AIR SYSTEM WITH MODULATING CONTROL OF ROOM TEMPERATURE AND
HUMIDITY IN INDOOR SWIMMING POOLS.
Time controller of heat proportional temperature and proportional humidity control with outside air
variation. Compensation of supply air mixing with glass wall sensor in order to avoid condensation
phenomena.
OPERATION
The controller time controls, with PI action, the room temperature through sensor (2) by driving the
valve (4) on the heating coil. Room humidity control by drier outside air supply which is introduced
indoor after being heated by the heating coil in order to reduce humidity. Through the room
humidity sensor (3) the damper controller (6) ensures that only the outside air, necessary to
maintain the desired humidity set-point, is introduced.
The humidity set-point is compensated by sensor (1) placed on swimming pool glass walls and
connected to SC input. When inside temperature of the glass wall surface, due to low outside
temperature, decreases up to the condensate value of room humidity, the compensation reduces
linearly the set-point of room humidity avoiding condensate phenomena. Limit action (anti-frost or
max temperature) on D.i.1 digital input.
ModBus supervision is possible.
Frost protection:
in case of heated fluid lack or of faulty control, if the anti-frost thermostat (5)
detects a temperature lower than the set value, the controller stops the fan by closing the outside
air damper.
Obstructed filter
: the pressure switch (7) signals the presence of obstructed filter if the differential
pressure before and after the filter, increases over the set value.
Possible Variants:
it is possible to use a cooling coil of on/off condensation on output Rel2 to
increase the humidification when the outside air is wet.
