No vent to use, but that’s where some say using a step or ramp help with this issue. Gently warm up the chunks vs. blasting them with high heat. I’ll say I have noticed a difference in the type of smoke coming out of the vent hole when I started ramping the temp, was much lighter and thinner.
They type of wood could play a part in the smoke as well, perhaps being too dry. Just a thought, lots of thoughts both ways on the wood, whether big box stores or specialty wood shops are better, but also thinking of shelf life for any type of wood.