Queensland Institute of Medical Research

Alan Stockman, Building Services Engineer

QIMR has recently installed a complete Optimice/MICE system within its remodelled animal facility. Installation was completed using a central extract ductwork system employing the proprietary accessories supplied with, and available for, the caging system.

Ventilation rates were determined using the data supplied for effective ventilation of the cage system as supplied by the manufacturers and final balancing of the system was effected by use of individual rack mounted balancing dampers. The system balance was achieved with minimal effort and we achieved the optimum ventilation rate for each rack without any problems. Overall control of the extract system was achieved by the use of a pressure controller within the ductwork system and a variable speed drive applied to the main extract fan.

We have found the system to be very effective under forced extract conditions and also have run the system for over 24hours without the forced extract fan in operation without any adverse conditions becoming apparent within any of the rack mounted cages. Failure of any part of the rack system ventilation is very easy to determine as an occupied cage mists up to show that there is no airflow through the cage, as we have determined after an inadvertent partial disconnection of the vent hose by one of our operators.

As with all essential ventilation systems we have spare motors on site in the event of a motor failure. We can complete a motor change within two hours of failure and this allows us ample time should the current cage ventilation system fail since the cages will retain a certain amount of natural ventilation as previously noted under our 24hour test.

Essentially, the cage system is well constructed and requires little or no maintenance. The set up installation of the racks was simple and the final commissioning took less time than expected.