Fortunately our building does have a backup generator so heat has been a minimal issue in our personal server room. But we have found keeping the lights off (we have these neat little lights we keep for walking in and out without need to reall turn lights on) and not haveing the monitors on makes a huge difference in itself. Every so often we pruchase a KVM to consolidate a few machines to a single monitor. Also we have a two sided room with electricitiy coming in from two ways. Generally when one side is out (which in itself is rare) the other is always up so if needs be we swing the plugs.