IRRI's semi automated downdraft rice hull furnace (dRHF) provides hot air to flatbed dryers for drying grains, seeds, and other crops. The quality of hot air also affects the quality of the seeds and grains being dried. If the furnace's combustion chamber produces dirty and heavy smoke, it could negatively affect the aroma, taste, and color of the dried product.
Some units have been piloted in different areas in the Philippines to test the efficiency of this furnace. Some cooperators continued to manufacture dRHF units.