Solution for Mildew forming in vacant house

[Chris DeTreville]

Ok, the company I work for manages some low income houses in a rough area. Every time someone moves we have to go in immediately and take all the appliances out and put in storage, and board up the windows to secure the place. We also take out the window units so they don't get stolen and we screw the crawl spaces shut to discourage copper thieves. Anyway, one of these houses we have is completely renovated and on the market for rent. I went in to show it the other day and noticed a light dusting of mildew forming on the floors. Also, the freshly painted cabinets in the kitchen were starting to develop a light green mildew. So, since we have to keep the windows boarded, and can't have AC running...does anyone have any ideas as to how we could stop the mildew from coming back once we send someone to clean it up? We'd prefer not to have anything plugged in and running on electricity- that's the rub. I have looked for battery operated fans or dehumidifiers but have had no luck. Most of them are too small to be effective. Any suggestions?

Also, I had someone look up under the house and it looks to be dry. I think we are having this issue because of the high humidity lately.