Hello Bob...........my name is XXXXX XXXXX I will be happy to assist you with your electrical question. My goal is to exceed your expectations on Just Answer!
1) For optimum performance on a 15 foot ceiling, typically the blades of the ceiling fans will be anywhere from 9 feet to about 12 feet above the floor level. You can go lower or higher, but I would not recommend to install the fan blades any lower than around 8 feet 6 inches or so above the floor line.
2) The down rods come in 12", 24", 36" 48" and 72" versions. For your application, I would recommend using a 36" (3 foot) down rod and you should be fine. This will provide you with approximately 12 feet above the floor level (give or take a few inches due to the fan canopy) and using a 60 inch diameter fan will provide a good air movement. The 48" down rod is also an adequate length if you want the blades lower, but I would recommend to not go any smaller than the 36" size.
3) Since the ceiling is somewhat taller than normal ceiling heights and you are also using a larger diameter fan (60 inch), I would go with the 36" down rod, since this height will blend in better with the ceiling height as well as the diameter of the fan. I think this height is more appealing to the eye versus if the fan were lower.
Hope this helps.........If you have any additional questions, let me know and I'll be glad to answer them for you.
Otherwise, don't forget to rate me before you log Off.The next time you have an electrical question, you can also request for me at:http://www.justanswer.com/home-improvement/expert-your-electrician ..........Thanks..............Kevin!
Hello Bob............Thank you for the excellent service rating as well as the bonus.........much appreciated!
If you have any other questions, let me know and I'll be more than happy to answer them for you.
Take care and have a great day...............Thanks...................Kevin!