Ok guys with the oil heater I keep my hotspot and cool spot and temp gradient to specs. Because of the PVC enclosure I am able to keep them pretty constant as long as it wasn't an overly warm day "max cool side 83" maybe I need to monkey with my settings on the oil heater or look into that RHP. Problem being with either those or the lights is I won't see the results of my work until the end of the month plus I wouldn't put it past the power company to jack the rates up. North Carolina here...they make their own rules on a lot of things