I use both, ifin all I got is chips, then chips it is, ifin I got both, I'll mix some chips in with the chunks, chunks will burn longer then chips, but chips will get goin quicker. That smoke towards the end is gonna be nigh onta invisible, ifin ya open the door, yall will see just a hint a the smoke. Besure ta shake yer pan ever now an again ta keep the wood in good contact with the pan.