Unlikely that your dryer will be able to push the moisture laden air up 14'. And as you are finding, the moisture condenses inside the pipe if it goes down and then back up. Can't you vent straight out level?
If not, at least drill a hole maybe 1/4" diameter in the bottom of the vent pipe at the bottom of the run. Not the best solution if this is a gas dryer since this will allow combustion gases to accumulate down there.