Steam Heating: Steam is produced in a boiler and then distributed through pipes into the kiln. The steam transfers heat to the air in the kiln, which then heats the wood. This method is widely used in larger facilities due to its efficiency and ability to maintain consistent temperatures.

Direct-Fired Heating: In this method, a burner directly heats the air that is then circulated through the kiln. The fuel can be natural gas, propane, or wood waste. Direct-fired kilns can be more energy-efficient, but they require careful control to prevent uneven drying or overheating.

Indirect-Fired Heating: This approach uses a heat exchanger to transfer heat from a combustion source to the air in the kiln without direct contact. It provides a cleaner heat source since combustion by-products do not enter the kiln, which is beneficial for certain types of wood or end-use requirements.