Whether it's a vent or exhaust pipe for your dryer ... are different types of vents. Some, like furnace and water heater vents, are usually white PVC or aluminum pipes sticking out of the wall.

"The flue pipes outside of the furnaces are typically in PVC pipe,” said Ron Zandron, with John Boiler Works. “The ones that tend to go out near the ground have the opportunity for snow to ...