Dryer vents come in all shapes and sizes, but the most common dryer vent size is 4 inches in diameter. This is the standard size across all major brands of dryers, and it’s designed to accommodate the venting needs of most residential laundry setups.
A 4-inch diameter allows for plenty of airflow, which is necessary for efficient drying. Your dryer needs to be able to push out a large volume of hot air in order to evaporate moisture from your clothes quickly and effectively. With a 4-inch diameter dryer vent, you can expect improved drying times compared to smaller vents.
In addition to improved drying performance, larger vents also help reduce the risk of lint buildup inside your ducts over time. Lint can be very flammable and create a fire hazard if it accumulates too much inside your ducts. A larger diameter vent helps reduce this risk by allowing more air velocity that carries away lint particles instead of trapping them inside the ducts.
For these reasons, many building codes now require that new construction homes have at least 4-inch diameter dryer vents installed during construction. If you’re replacing an existing dryer vent or installing one from scratch, you should always choose one with at least a 4-inch diameter for optimal safety and performance benefits.