where to vent
I think you can do it either way. The heat in the dryer shouldn't get above 160 then the stats cuts the power to the element until itcools down to about 120 when power is sent back to the element. In other words, the averae tempt should only be about 140. Older ones would average about 130, if I am thinking right. Been a few years, I may have those tempts backward. I suspect I do, seems like the older ones got hotter.
If I was going to cut a circle in the block, I would drill holes with a masonary bit and hammer drill in the outline of my circle as close together as possible then chisel or knock it out.
Girltech? Where are you?!