Published in the September 2010 Australian Longwall Magazine

But the power cost alone in providing ventilation can easily exceed all other mine electricity costs combined, and in larger mines can run into many millions of dollars.

On top of this is the cost of mining shafts and other infrastructure to deliver ventilation, and the cost of maintaining fans and infrastructure.

Finally, the cost of poor ventilation on the health, safety and productivity of underground workers should not be ignored, nor should the tragic mining disasters stemming from poor ventilation and gas build-up ever be forgotten.

The promise of future double-digit percentage increases in power costs, and tougher air quality restrictions legislated for underground mining only serves as a warning for mines to start considering their ventilation costs and designs more closely.

While occupational health and safety standards must be met, there are many opportunities in most mines to dramatically reduce ventilation costs (while increasing airflows) by accurately modelling the mine ventilation system.

Once this is done, many are surprised to discover just where most ventilation costs are coming from.

Often just a few poor decisions in mine ventilation design can lead to bottlenecks and increase ventilation costs that persist for the life of the mine.

Airway or shaft size, for example, is a crucial factor when designing ventilation, and few people realise the cost of getting sizing wrong.

For example, increasing a designed shaft diameter from 3.0 metres to 4.5m can cut the cost of the ventilation power through the shaft by 87%.

Another opportunity becoming more available to mines is demand-based ventilation, where fan speeds and ventilation controls are adjusted to provide ventilation when and where it is needed most, reducing costs elsewhere.

Computer software is an ideal tool to analyse these considerations, and Ventsim ventilation software is used and trusted by hundreds of mines, ventilation consultants and research organisations for this purpose.

Ventsim software has been used in coal and metal mines in Australia for more than 17 years, and the new Ventsim Visual released last year is quickly becoming a popular successor to the original Ventsim Classic software.

Ventsim products are designed to simulate airflows, pressure and heat from a modelled network of airways. Ventsim was the first ventilation package to integrate an easy-to-use Windows graphical design with a 3D graphics interface.

Once an existing or newly designed mine ventilation environment is modelled in Ventsim Visual, the program dramatically presents the mine in full 3D colour and animation showing existing or predicted ventilation data such as airflows, pressure and costs, as well as any opportunities to improve ventilation or reduce mining or power costs.

With automatic financial optimisation wizards, analysers and numerous graphical and graphing tools available, the process of designing and optimising ventilation design and reducing costs becomes a much simpler and more intuitive exercise.