What characteristic of top feed delivery systems enhances ash removal?

The characteristic of top feed delivery systems that enhances ash removal is their improved grate design. This design plays a crucial role in efficiently managing the combustion process and facilitating the movement of ash away from the burn area.

With improved grate designs, the combustion process can be optimized, allowing for better airflow and more complete burning of the fuel. As the fuel is introduced from the top, the ash that is generated is more likely to fall through the grate and be collected in the ash pan below. This minimizes the chances of ash buildup in the combustion chamber, which can hinder performance and reduce efficiency. Additionally, this design helps in promoting a cleaner burn, which results in less unburned material that can also contribute to ash accumulation.

The other options do not specifically address how ash removal is enhanced in top feed delivery systems. Manual ash removal does occur but is not a feature designed to improve efficiency, cooling systems serve a different function, and burning fuel at lower temperatures can actually produce more ash rather than enhance removal efficiency.