You can locate them in any commercial or industrial building, but what exactly is the function of a cooling tower and why is it so important to maintain them? First, let's begin by identifying the different types of cooling towers that may be in your building. There are generally two types of cooling towers, Natural Draft or Mechanical Draft.A mechanical draft cooling tower are normally smaller, uses fans to generate air flow and are normally more expensive to run. A natural draft cooling tower facilitates air flow by the natural convection of the air, is normally less expensive to run, however, larger in size than a natural draft cooling tower.