Hi Allan, I've been thinking about something myself. All the metal in my observatory is wet in the mornings after a night of imaging. It's pretty damp here but mould doesn't seem to be a problem.
I am looking at some hardware like this to help,
http://www.ebay.com.au/itm/250815177663?hlp=false
I might even be able to afford to power this. It should cost about $15 / quarter to power. I like the idea of a drain hose going outside. I just ordered one so will let you know how it goes.