Frequently when conducting a home inspection we come across clothes dryers that are either improperly vented or not vented to the outside at all. It is not uncommon to find clothes dryers directly vented into a crawlspace or garage area. Many amateurs and some contractors find it more convenient to vent dryers into these areas. This practice has several draw backs. The number one problem is the moisture that is created. Moisture build up invites mold, wood rot, and vermin just to name a few. An average family of four produces 26 pounds of moisture a day.
Another problem created is the lint that gets deposited into these areas. The lint can cling to wood framing slowing down the normal drying process of the wood. The lint will also clog crawlspace vent screens further adding to the moisture build up which causes several other moisture related problems. A large enough lint build-up can also create fire hazards. Lint has a much lower flash point than wood and can ignite by a single spark. Significant lint build up can also make it difficult to conduct a proper inspection, and make future work in these areas much more dirty. Below are a few things to note in order to properly vent your clothes dryer.
* Always vent dryers to the outside. Lint boxes and water canisters are not recommended. Never run vents into crawlspaces or garage areas.
* Always use metal vent hoses. The flexible version is best. Flexible vinyl dryer hose deteriorates quickly allowing leakage. It also may not meet local code requirements.
* Avoid sharp bends and multiple turns in the dryer vent run. Lint can accumulate in sharp bends. This can cause over-heating and lead to potential fires.
* * Use an appropriate vent flapper assembly at the outside exist point. This allows the exit of dryer venting while preventing the entrance of vermin. This area should also be periodically inspected and cleaned out as needed. Repair any damage as needed.
* * Be sure to secure the vent hose to the back of the dryer with an affixed hose clamp. This prevents the hose from becoming disconnected and allowing lint build up directly behind the dryer.
* * Always be sure to inspect the dryer lint trap regularly. Clean and remove lint as necessary. Many newer type dryers have alarms to warn you of excessive lint build up.
* Never reduce the vent hose size from the size of the opening exiting the dryer.
* * Try to limit the length of the dryer vent run. The longer the run, the more difficult the proper venting.
HHI Article # 44