Building Codes and Inspections/Dryer and Fire Issues
This question is not code-related, but we think you might have the expertise to offer guidance for this fire-related issue. We are purchasing a home whose dryer vent goes up inside a wall and through the attic. We are trying to figure out how to clean the lint from it periodically. We watched online videos, and they showed just the part where the hose attaches to the backside of the dryer being cleaned out. We thought the entire tubing of the hose should be cleaned out periodically. How the heck are people pulling the tubing out from a wall and putting it back in etc. Any suggestions appreciated. Also, are rigid or flexible hoses better for these situations. Thanks.
You might be able to access a joint in the attic that you can slip apart the vent pipe so you can clean the pipe with a brush downward to the dryer and outward to wherever the dryer discharges. Use hard pipe rather than flexible, as the smooth surface won't catch lint, and will be easier to clean. Joints should be taped and not assembled with screws for the same reason. Where the vent attaches to the vent pipe in the wall behind the dryer, I just push that on so if the vent ever gets blocked, the air pressure will blow the joint apart and you will know it, otherwise if it gets blocked, hot air will just back up into the dryer and lint will collect even more, and drying will become ineffective.
Dryer vents should be as straight and short as possible. When homes are built, the builder has no clue what dryer will be installed on the vent, so general code guidelines are used with a maximum run of about 25 feet with that being shortened depending on the number of bends in the vents. The more bends, the more the vent length is reduced. Builders don't like running a dryer vent out the front of the house for aesthetic and practical reasons, so sometimes they run them out the back or through the attic which can result in the vent length being too long for the dryer blower to exhaust the lint all the way out. Long horizontal runs with pipe that gets a sag in it becomes a lint trap which can eventually block the pipe and flow. The use of anti-static or fabric softener dryer sheets can also make lint clump up. Many dryer manufacturers tell you not to use them.