Dryer Installation: How To....

1. Allow at least 4 inches of clearance to vent out the back of the dryer. This will allow for the offset of the venting elbow. If you vent off the top of your dryer, cut out the vent hole by drilling a hole with a drill and cutting it to the proper size with tin snips.
2. The method you choose to exhaust your dryer depends on many different factors. Choose the most efficient route from your dryer to the outside.
3. Use a hinged damper weather hood to prevent back drafts and place it at least 12 inches off the ground. Be sure the placement of this vent will not exhaust dryer air to a window well, gas vent, chimney or any other unventilated area (such as attic or crawl space). The accumulation of lint can be a fire hazard so check your local safety code on this issue.
4. Connect the exhaust system with rigid aluminum pipe and wrap joints with duct tape. Avoid using sheet metal screws. Hang the aluminum pipe from appropriate hangers on horizontal lines at the critical distances determined by your local building code. 

Related links:

~ Venting lengths

~ Dryer hook up tips

~ Changing from a 3 to 4 prong cord

~ Wiring a common 4 prong receptacle 

~ Reversing a common dryer door swing