Dear Sir and Madam,

By entering into a joint venture with Delta Controls, SCHAKO has successfully reduced the significant overhead involved in integrating the typical LON solutions available in the market. At the request of a planning office, the two companies developed a solution that combines Delta’s BACnet VAV (variable air volume) controller with SCHAKO’s VAV controller with VRA-Q-E damper unit. This seamless BACnet architecture saves on material costs and engineering thanks to a number of significant advantages:

• Only BACnet offers a seamless yet open communication protocol, from the field level up to management level, which also incorporates rich functionality such as trending, alarm management, scheduling, etc.
  
• BACnet automates the integration of DDC technology with the control environment without requiring additional engineering overhead, through the automatic BACnet
  services (plug and play).
  
• In addition to the basic functionalities, the freely programmable BACnet VAV Controller DVC-V322 (B-AAC) also enables complex applications to be custom programmed (averaging of several temperature sensors, summation of air volumes for
  control of air balancing).
  
• The cabling can be implemented using a cost-effective 2-wire bus with BACnet MS/TP.
• Installation costs can be reduced as additional outputs are available on the controller. Actuators are powered from the unit, which means that only one controller power source is required.
  

All necessary parameters were factory configured by SCHAKO and Delta, and are stored in the backup flash memory of the controller.

The variable air volume controller with SCHAKO VRA-Q-E damper unit is well suited to fast, safe and pressure independent control of air flows in VAV systems. The integral differential pressure transmitter, damper drive and electronic control together form an autonomous control unit. The differential pressure transmitter and double cross flow unit from SCHAKO combine to provide precise measurements.

The double cross flow unit incorporates 12 holes (measuring points) in the incoming and outgoing airflows, respectively, distributed in accordance with the median line method. This very accurate method of flow rate averaging enables this VAV controller to be installed even after short distances of continuous air flows, e.g. downstream of non-linear duct sections.