Booyco Engineering has custom designed and manufactured the crew cooling system for the RG 35 vehicle for BAE Systems Land Systems OMC.

The large RG 35 six-wheeled armour personnel carrier currently being developed by BAE Systems Land Systems OMC can accommodate 16 people. This vehicle is a multi-role unit allowing the same platform to be set up for different applications.

The crew cooling system is an integrated heating and cooling system which uses a Booyco developed electronic controller and is the largest such system manufactured by Booyco Engineering for a military vehicle.

Flexible set-up possibilities

This dual system comprises separate front and rear systems with the rear system being split into two individual cooling systems. Both systems are independently controlled by the electronic controller. Cooling is provided by two independent systems, which supports the functionality that both systems can be installed if the vehicle was to be set up as a personnel carrier. However, should the vehicle be changed to a non-personnel vehicle the front system is kept for the driver and co-driver and the rear system can be removed.

The front system, with a 7kW cooling capacity and a 6kW heating capacity, is located beneath the dashboard and the air is distributed through the driver’s portion of the vehicle using ducting.

“This is a split system with the evaporator mounted internally and the condenser mounted externally, with the compressor mounted to the engine,” explains Grant Miller, project engineer of Booyco Engineering. “Space constraints on the vehicle dictated that the system be designed so that the condenser serves both the front and rear systems. It is also equipped with demisters to ensure optimum visibility for the driver.”

The rear system has a 14kW cooling capacity, with 12kW of heating capacity, and is mounted inside the roof above the rear door. Air from this system is used to cool or heat the personnel via roof mounted ducting.

Tested in maximum operating conditions

“As with all Booyco air conditioning systems, the unit was fully tested in our climate chamber,” says Miller. “For thermodynamic testing, the climate chamber was set at 55°C with the relevant humidity levels, to simulate the maximum operating conditions that the system is designed to handle.”

The climate chamber is equipped with a data acquisition system that can be linked to temperature, pressure, humidity, current and voltage measuring devices. Using combined airflow measuring equipment, calibrated annually as required by ISO 9001, the chamber provides a complete and accurate measure of the performance of the cooling system.

“The climate chamber is used to validate the performance of the system against the specifications, allowing us to provide customers with fully documented test reports and proof of the hardware’s ability to achieve the requisite cooling capacity,” Miller explains. “When necessary, we also arrange external independent testing of the entire vehicle with accredited testing agencies.”

He adds: “The system design posed a number of challenges including its sheer size in terms of both volume and capacity. We also paid close attention to optimising the system in order to effectively contain costs for the customer.”