the heat will lower humidity and raise temp, make sure you keep a close eye on the temp. I'd try maybe heating the room your closets in, or heating the air just outside the closet and trapping it in. Make sure your Rh is b/w 40%-50% or else your buds are gonna get crispy on the outside too quick, cause an uneven dry, and your buds will smell like hay/grass/clorophyll on the outside.
edit: And you need to make sure air is circulating through that room not directly blowing on buds.