18
TM SmartCool One 5057724 v1.0_08_2022
BMS Interface Card
BMS Interface Cards can be factory fitted and interfaced with most BMS. A wide range of protocols can be
accommodated through the use of interface devices, with ModBus/Jbus and Carel available as standard options. Please
contact Airedale to discuss the licensing requirements for other interfaces such as SNMP, LonWorks, Metasys and
BACnet. Airedale’s own supervisory plug-in BMS card, pCOWEB, is also available and is based on Ethernet TCP/IP
secure technology with SNMP features. It requires no proprietary cabling or monitoring software and can be supplied
preprogrammed with an IP address for ease of set up. Cables to the BMS to be supplied by others.
Constant Air Volume
Constant air volume is a method of automatically adjusting the unit fan speed to deliver a specific air volume. When
faced with a change in system resistance, the fan speed modulates to obtain the air volume set point. Constant air
volume monitors the air pressure differential between two points. These two pressure points, positive and negative, are
routed back to an air differential pressure sensor inside the unit.
Constant Pressure Control
Constant pressure control is a method of controlling air pressure within a space, such as a floor void or a duct. The air
pressure is controlled using a variable speed fan that is modulated to maintain a given set point. Constant pressure
control monitors the air pressure differential between two points. In a typical application (shown below) the pressure
under the raised floor (red) is compared to the room pressure (blue).
The two pressure points, positive and negative, are routed back to an air differential pressure sensor inside the CRAH
unit. The value from the air pressure sensor is compared to the set point and a fan speed demand is generated, to
maintain the required pressure differential.
It is the responsibility of the installer to fit the air pressure sensor(s). The sensor shall be located under the false floor or
in the return air duct with the 6mm flamtronic tubing routed back into the control panel of the unit. The tubing must not be
obstructed or damaged to ensure accurate pressure control. The constant pressure system can only be commissioned
by Airedale once tubing has been routed from the pressure diffuser to the unit. A maximum of 8m/s air velocity is allowed
at the diffuser so consideration must be made when locating the diffuser.
Fixed Fan Speed Control
Fixed supply fan speed control allows the user to dial a 0 – 10 volt supply voltage directly into the fans. This method of
fan speed control allows for a constant fan speed due to the constant 0 – 10 volt source to the fan via the controller.
Modbus Fans
Modbus fans provide individual fan feedback of speed, temperature and alarm status. Fans are controlled via a 0 – 10
volt output.
SmartCool™
Precision Air Conditioning
Introduction