Is there a word that could be used interchangably that would describe the proper direction to face that is away from the sun that would be appropriate for both the northern and southern hemispheres?

Antiheliotropic? Antiheliotactic?

Interestingly, Websters defines heliotropic as "turning toward the sun", but AHD defines it as "growth ... toward or away from the light of the sun". Comments?

http://www.dictionary.com/search?q=heliotropic