DHW Coil for Pocono

I am a new owner and have decided to add DHW. I have read that if you install horizontally rather than vertically, the coil should be tilted. The question is, how much tilt in inches from the top nipple to the bottom nipple?

Am I correct in assuming that the tilt is to facilitate the thermo-siphon effect?

Thanks for any info / insight to above.

This is a great site. I have already learned quite a lot about the "ins" and "outs" of burning coal in a stoker stove.

For good thermosyphon, your tank must be less than 10 feet from your stove. otherwise, you need a pump to help circulate it.

Is the 10 ft. the actual, straight line distance from stove to tank, or is that in "pipe feet", measuring the length of pipe to go from the outlet of the DHW coil from the stove to the inlet on the tank?

Here some good info that might help, been posted before...

http://mha-net.org/msb/docs/dhw2.PDF