Prediction of condensation in caves Speleogenesis and Evolution of Karst Aquifers

Condensation is an important process in karst environments, especially in caves where carbon dioxide enriched air can lead to high rates of condensation corrosion. The problem is there has been very little research reported in the literature dealing with condensation as a microclimate process. This study addresses the problem and reports on a method for measuring and predicting condensation rates in a limestone cave. Electronic sensors for measuring condensation and evaporation of the condensate as part of a single continuous process of water vapour flux are tested and used to collect 12 months of data. The study site is the Glowworm tourist cave in New Zealand. Condensation is a function of the vapour gradient between rock surfaces in the cave and cave air. The size of the gradient is largely determined by air exchange with the outside. The results show that the numerical model to predict condensation works well. Given that rock-surface temperature in the cave does not vary much, condensation is essentially a function of cave air temperature and the processes that affect it, mainly, air exchange with outside. The results show that condensation can be controlled by controlling ventilation of the cave.