I've got my equipment in a AV cabinet with a glass door, and no backing. Obviously my equipment (especially my Yamaha HTR-5590 receiver) gets pretty hot in there. Instead of getting a new AV shelving system with no sides, what can I do to improve ventilation? I was thinking about adding some 80mm computer fans to the cabinet, either at the back or drilling holes above the receiver. But is there an easy way to power these 12V fans? Or else, what other options do I have? TIA.