Assortment / System Description

Room pressurization and fume hood control
Pressurized room, temperature control
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21.7.2 Ventilation control
Ventilation in pressurized rooms can be defined as the rate of airflow through a
room to remove and dilute air contaminants. The application sets supply and
extract airflow rates to satisfy ventilation requirements. In a positive pressure
room the ventilation rate equals supply flow. In a negative room, it equals
extract flow. The pressurized room application has three options for ventilation
control:
● Minimum ventilation collaborates with the room pressure control
application for ventilation purposes. The ventilation rate is selected from a
set of configured values based on room operating mode and HVAC plant
mode.
● Minimum ventilation and demand-controlled ventilation DCV collaborates
with the room pressure control application for ventilation and/or room air
quality control purposes. The current ventilation rate for a room is selected
from a set of configured values based on room operating mode, HVAC plant
mode and measured CO2 concentration. The minimum flow depends on
occupancy. The DCV function can be disabled according to occupancy.
● Minimum ventilation and external demand-controlled ventilation DCV
collaborates with the room pressurization application for ventilation and/or
room air quality control purposes. The current ventilation rate for a room is
based on occupancy and a DCV signal generated by a separate controller,
device or system (by others) and written to an object in this application
function. The minimum flow depends on occupancy. The DCV function can
be disabled according to occupancy.
The pressurized room application configures a minimum supply air flow in the
temperature control dead zone. The function can be configured individually for
all room operating modes.
Description Name Default value
Minimum room ventilation for comfort
▶ Do not leave at default - set according to job
specification. (Minimum room-ventilation setpoint for
Comfort.)
This is the ventilation rate needed in the room during
Comfort mode. The value must come from the
ventilation engineer’s specifications. It may be
specified as the "occupied ventilation rate" or as the
only ventilation rate for the room.
RVntMinCmf 0
Minimum room ventilation for pre-comfort
▶ Do not leave at default - set according to job
specification. (Minimum room-ventilation setpoint for
Pre-Comfort; might also be specified as "standby
ventilation rate".)
If Pre-Comfort is not specified, the value for Comfort
mode might be used. This helps if the room operating
mode is set unexpectedly.
RVntMinPcf 0
Minimum room ventilation for economy
▶ Set according to job specification. (Minimum
room-ventilation setpoint for Economy. Might also be
specified as "unoccupied ventilation rate".)
If Economy is not specified, the value for Comfort
mode might be used. This helps if the room operating
mode is set unexpectedly.
RVntMinEco 0
Minimum room ventilation for protection
▶ Set according to job specification. (Minimum
room-ventilation setpoint for Protection.)
If Protection is not specified, the value for Economy
might be used.
RVntMinPrt 0