What is the max length of the dryer vent tube? I just moved my dryer to get the vent tubing off the floor in the garage. To do this, I had to run the tube up about 6 feet and over about 23 feet. The dryer only dries the clothes completely in timer mode. The vent system under the dryer is clean. The vent louver doors open all the way when drying. I added a total of about 12 feet to this vent. It worked O.K. before. I know this seems like a no brainer, but we have had the dryer for 2 years...so, may be the dryer itself....