Q. We rent a duplex less than five years old, and there are considerable problems with condensation and mildew, especially around the windows. In the wintertime, we must use towels to absorb all the water. I realize an air exchanger would remedy the problem, but our landlord does not. He says the problem is due to the fact that a family of four live in the house. However, only one person lives in the other half of the duplex and …