There is extensive evidence from SoHO and other data that “micro-events” play an important role in sustaining at least some components of the solar corona. These are often termed coronal micro-” heating events” though a major part of their role is feeding coronal loops through chromospheric evaporation. We consider what can be learnt from these data concerning the energy release and transport mechanisms driving the evaporation, including thermal conduction and fast particles. We conclude, from one large event and the statistics of many small ones, that conductive evaporation alone does not fit observations and that fast particles or some other nonthermal driver must be involved.