Clothes dryer vent buckets are often used by homeowners whose laundries are not properly vented. They are commonly sold in hardware stores and, when regularly maintained, appear to perform their intended functions adequately. But it should be clearly understood that dryer vent buckets do not comply with the requirements of the Mechanical Code.
There are two reasons to require an exterior dryer vent: The first is excessive moisture, and the second is lint. When the water in a load of laundry is expelled into a building, moisture condensation can cause fungus and mold infection. When lint accumulates inside a building, the buildup can pose a fire hazard.
A vent bucket can trap some or most of the moisture and lint, but it cannot catch all of it. What’s more, the vent bucket depends on continued maintenance of the water level. If the water is spilled out or if it is lost by evaporation, the bucket becomes useless.
Ask your plumber if there is a practical vent path from your dryer to the exterior of the building. If so, this would be a worthwhile upgrade. If not, you may have to continue using the bucket. When you eventually sell your home, the dryer vent should be disclosed to buyers as a noncomplying condition.