1) How warm do you keep them?
2) What is your optimal temperature and how much fluctuation do you allow?
3) What is your method of heating? (Please note I'm not all that curious to know what kind of heat you're providing in your racks, but what you use to heat the ambient air temps) Baseboards? Oil-filled heaters? Heated flooring? Anything else?
4) Do you provide a night-drop of ambient temps?
Let me know, I am thinking of making some modifications to our room.