Ventilation Duct Criteria Pro's and Con's. How to Effectively Lower Operating Costs During the Tender Process.


Michael Shearer, CPB Contractors; Johannes Holtzhausen, Oz Minerals

An analysis of operating costs for underground mining operations in the current global economic climate considers the financial burden for a ventilation system to be in vicinity of 30 – 50%. These operating costs are often overlooked by management teams in the greater scale of things when looking to save money in the procurement phase. This oversight to operational costs can be as little as the effective delivery of ventilating air to the work zone. One of the biggest opportunities for substantial savings and improvements can be realized in the selection of a quality vent duct that is suitable and fit for purpose. The key component to the selection process for quality products is a solid specification criteria that is followed during the tender process. This allows the management team to filter out unsuitable suppliers and products. The case study identifies some of the key components that were considered in the procurement and selection process for lay-flat ducting products at large metal mines. The characteristics of the selection criteria also considered a ducted performance comparison that offers the best aerodynamic performance with some of the following components. • Airflow at Duct Face (m³/s or cfm), Fan Pressure (Pa), Air Power (kW), Assumed Fan Efficiency, Annual Running Costs, K – Factor or Lambda, Leakage Factor, Joining Method and available Duct Lengths with weights, etc. Critical components were the current testing standards available for: • Bursting / Pressure Strength, Mass Weight, Tensile Strength, Tear Strength (Weft / Warp wing tear) Other key considerations were: • Coated Woven Polyethylene, Warranty Claim, Damage claims, Local storage / operations, community engagement and relationships, current testing data, previous issues, after sales service with technical assistance, etc. Hidden costs associated with product failures and operational stoppages are often not quantified during the tender process. Buyer beware.