CeeBee thanks I was wondering if I needed a circulation fan and maybe a heat shield directly over the elements. The SSRs that I'm using are just on/off but are you saying on the variable output controllers the output is pulse width modulated ? neat if so . this is the first temp controller I have used and I got these in trade so they didn't cost me much. They are Omega CN9000As and run about $250 new. My first test was with it in the on /off mode so I have to exp. with the other modes when I have time. Will post up a dwg. of a fan/heat shield setup soon.