Continuous monitoring of refrigerants in mechanical rooms with two chillers.

Early detection of a refrigerant leak in a mechanical equipment room can prevent dangerous health implications to occupants, minimize significant loss of refrigerant and eliminate additional energy costs.

Using Critical Environment Technologies Canada Inc. (CETCI)’s QCC Quad Channel Controller and two ART Infrared Refrigerant Transmitters is the solution. Infrared gas sensors are low maintenance, have a long life span and provide an accurate gas measurement at low concentrations.

Two ART transmitters inside the room provides continuous monitoring of potential leaks and their communication with the QCC Controller with a top mounted strobe and manual shut off switch mounted outside the room door provides a status of the air quality conditions inside the room prior to entry.

If a leak is detected an audible alarm will sound. The relays will activate a pre-set response, such as turning on a remote alarm device, turning off the chillers, actuating the mechanical ventilation system and/or triggering another set response as required.

 

Typical Double Chiller Room Refrigerant Monitoring System

  

The two ART gas detectors, each with an internal infrared refrigerant sensor should be placed covering the areas where a refrigerant leak is most likely to concentrate and where pooled refrigerant is likely to accumulate. Refrigerant gases are heavier than air and will concentrate closer to the floor and in areas with less air current. Each ART should be mounted 10” to 18” off the floor so it is at an appropriate height for detection and accessible for routine calibration and maintenance. Gas measurement readings will be transmitted from the ART gas detectors to the QCC Quad Channel Controller and the information will be viewable on its display.

The QCC Quad Channel Controller should be mounted outside the mechanical room entry door and be equipped with a top mounted strobe and manual shut off switch (meets B52 code requirements). It will interface to the two ART transmitters inside the room and will display the target gas levels for viewing prior to entering the room. The QCC is pre-programmed and field adjustable. Functions that can be set include relay assignment, time delays, logic control, sensor types and ranges, alarm set points, etc. There is a 4-line x 20 character backlit LCD display that actively scrolls through the programmed channels and displays the gas name, concentration and alarm status. The QCC should be configured to set off alarms and activate the exhaust ventilation system, shut down the chillers or other alarm procedures as appropriate when a leak is detected. The QCC can accept inputs from up to 4 analog and/or digital transmitters using Modbus® RS-485 digital communication. (BACnet® MS/TP output is available if required to communicate with a BAS).

Remote visual and audible alarm devices such as the Remote Strobe & Horn (RSH-24VDC) should be set up inside the room and if there is another entrance to the room, a QCC-RDM Remote Display Module should be mounted outside the door of that entrance, to provide visual confirmation of gas level readings prior to entering the room.

QCC model numbers that comply with B52 Code requirements: QCC-M-L-SW and QCC-B-L-SW

Cold Storage Application

Single Chiller Application (DCC + ART)

Double Chiller Application (QCC + ART)

Double Chiller Application (QCC + LPT-A)