I have old sash windows - they're draught-proofed and work fine, but I do find that at this time of year I get dreadful condensation on the inside of the windows, pooling at the join between the two halves of the window (where it then goes black and mildewy) and at the bottom of the cill.
What do you do about condensation on single glazed windows?
By using a dehumidifier and digital hygrometer, you’ll be able to keep the relative humidity in an optimal range and reduce the problems associated with condensation, including mold and water damage.
Water on windows is condensation, and it can be a problem. However, it's not a window problem, and the solution does not come from the windows. However, it's not a window problem, and the solution does not come from the windows.