Dryer Location

• Where your dryer is located will largely determine how you vent the hot air. A dryer that is located with the exterior on the other side of a wall can make for an easy dryer vent. This simply requires cutting a hole the size of the vent cap and attaching the proper piping to ventilate it.
  A basement location will require creating a path that leads to the exterior of the house, somewhere above ground level. Often this requires a couple of bends in the pipes and only needs a path of 10 to 15 feet.
  
  At AsktheBuilder.com, Tim Carter recommends venting your dryer to the roof for optimal results. This is an energy efficient method that can be accomplished with 20 to 25 feet of piping.
  
  

The Vent Cap

• The vent cap is the the place where the hot air escapes. The larger the vent cap, the easier it is to release the air. The problem with many standard vent caps that sit in a wall, say behind the dryer, is that these are no more than 3 inches wide. This doesn't allow air to escape fast enough to be efficient. Roof vent caps or vent caps with louvers offer less resistance making the dryer work faster. Look for a vent cap that allows at least a 4-inch opening.
  
  

Pipe Materials

• The flex pipe is an easy and convenient material. It doesn't take precise measuring and cutting to install and can be done within minutes, even for basement vents. Th problem is that flex pipes are first and foremost a hazard. In fact, Carter mentions that they are not even code approved any longer. You should check with your local building codes to be sure. The second problem is that all the flex in these pipes lower air flow and create more resistance. It also allows more cotton fibers to accumulate, which becomes more of a hazard.
  
  Carter recommends using 4-inch wide pipe that you can cut with tin snips and join with pipe clamps and duct tape. Use smooth pipes to promote air flow with the fewest joints possible. You can reduce dry times and make your home safer. If you are using pipe the roof in colder climates, insulate the pipes to prevent moisture build-up and condensation dripping.