don't sweat the temps man, i''ve personally grown hundreds of pounds of herb in the hot-as-fuck California summers, with the temps above 100, every damn day for like a month or longer, they grow just fine, as long as you keep the soil a good humid moistness
cardboard on top of the soil works great for that.
85 aint shit man
all these were grown in 100+ temps
The rh depends on the weather outside; right now the rh is between 20-30%. I was doing the towel method but didn't notice a difference. My apartment is an 108 yr old house converted into a triplex.
If your worried about heat get you a peice of 4" duct from home depot and hook it to one of the ac vents right there above it and run the duct to the pc.
Ps. pc cases are cool but server racks are better =)