When focusing on short runs, people usually run Vault of the Ancients in Act 2 or Warrior's Rest in Act 1.
I did 20 runs of Skycrown Battlements to see if it can be a viable alternative.
- Start in town, use waypoint to Stonefort, enter Skycrown and kill all the elites you can find. The area layout is always the same so you can't really mess up the run.
- I got 109 elites (elite packs + goblins) in 82 minutes which averages to 31 Demonic Essences per hour
Detailed Run Info:
Would I do this run regularly? No. For an extra 5-6 Demonic Essences per hour I miss out on a lot of loot.