Radiant charbroilers have the burner positioned under an angled piece of metal called a radiant. This directs the heat up toward the grates and food. Their angled design helps channel grease and drippings away from the flame and into the drip pan. Radiant models will get some flare-up, but it's generally more controlled and smaller than a lava rock model. Radiant charbroilers are much easier to clean than a comparable lava rock model.