A ventless dryer is a type of clothes dryer that does not require an external vent to expel hot air and moisture. Instead, it uses a closed-loop system to dry clothes by recirculating air. This makes it ideal for apartments or homes where venting is not possible. These dryers typically use either a heat exchanger or a condensation process to remove moisture from the air. As a result, they can be more energy-efficient and easier to install than traditional dryers. However, they may take longer to dry clothes compared to vented models.