fluoros are immensely cooler than CFL. My 32W T-8 tubes get about 98 lumens per watt, whereas most CFL range from 55-70 lumens per watt, so there's more light, less heat, and the emitter is much larger, so it has more surface area and has a lot less power put into it per square inch of surface. Plus the way I have them sitting, the ballast is at the top, and the tubes are sitting vertical, so natural updraft cools them too via the "chimney effect". I've been really surprised how gentle they are, and yet how they are producing good results thus far.