With ever-increasing energy costs and the modern focus on system efficiencies, the practice of ventilation-on-demand' is gaining momentum. Several examples, ranging from paper studies to practical examples have been recorded and another recent case study is presented here to encourage the practice. In comparison, cooling-on-demand' has received far less attention. This paper explores the possible merits of this practice by investigating the theoretical response of cool intake airways and the thermal interaction between the air and the rock, in order to gain a better understanding of the system behaviour and to quantify the possible savings. A case study is presented that demonstrates the improvements that can be achieved. Recent developments that allow live interaction between ventilation network models and on-line monitoring systems, have the potential for intelligent active control and alarming of ventilation and cooling networks. This will facilitate and maximise the benefits to be derived from ventilation and cooling-on-demand.