Booyco Engineering received an invitation to develop a customised air conditioning unit for the four-seater RG31 prototype vehicle BAE Systems developed in South Africa in mid December 2008, with a delivery date of the first week of January 2009.

“This was the fastest development undertaken by us to date, leaving us with only three weeks to design, manufacture and qualify the system. This clearly underpins Booyco Engineering’s track record of being able to meet stringent deadlines,” Daudi Uledi-Kamanga, design draughtsman at Booyco Engineering, says.

Uledi-Kamanga explains that the unit provides heating and cooling with the 24VDC evaporator internally mounted under the rear seats in the vehicle, thereby optimising space usage within the cab. “Air is supplied to the occupants of the vehicle via ducting within the vehicle body structure. The air supply is 99% recirculated air with 5% fresh air with both air supplies filtered at one common filter. Incorporated into the heat exchanger is a hot water coil which uses heated water from an external diesel heater to provide 5kW of heating to the occupants of the vehicle.”

“The relationship between humidity and temperature is critically important as it dictates what the appropriate cooling solution should be and as is our custom practice, all off-the shelf components selected for this unit were requalified by Booyco Engineering, specifically in terms of vibration and shock resistance, and high ambient conditions,” Uledi-Kamanga says.

“We capacity tested the system in the climate chamber at our facilities. This climate chamber has a data acquisition system that can be linked to temperature, pressure and humidity probe, and all our test equipment is calibrated annually as required by ISO 9001. The unit was found to produce 8kW of cooling at an ambient temperature of 55°C,” Uledi-Kamanga says.

“It also underwent rigorous vibration testing at Gerotek’s testing facility in Pretoria, giving BAE Systems the assurance that not only could we produce an extremely fast turnaround on request, but that the resultant product is within specified quality parameters,” Uledi-Kamanga concluded.