Fog Depth

Austin Arts

Mar 4, 2020
Hartford, CT
Would anyone have suggestions as to a good way to create a "moat" of fog utilizing the motorized orchestra pit (no actors or musicians would occupy the space)?
The pit preset would begin 10' below deck in order to hide, then reveal, scenery through a blanket of fog. I'm struggling with ways to fill that cubic space.

Ideas considered:
-foggers in the pit- concern being the control of the "billow effect"
-draping the space with fabric just below the surface to act as a layer for the fog to roll along ( fabric cost, anchor issues, and time make this difficult)
-fans in pit creating updraft that fog can travel "across"

Maybe someone knows of a high output unit(s) that would do this well??

Thanks for the input!


Well-Known Member
Jun 15, 2018
San Francisco, CA
I've never tried it but cold air is denser than warm air. Could have more A/C pumped into the pit a while before the effect is needed and then turn the heat on in the entire space minus the pit a few minutes before.
In theory the fog would fill and stay in the pit.

Easier, I like your fabric surface but not sure how you'd retract it.


Active Member
Jun 29, 2016
I've personally used just low-lying fog fluid in fog machines that take ice, but that fog does eventually warm up and starts to rise after some time. You'd have to keep the pit cooler than the rest of the auditorium to keep the fog low.


Renting to Corporate One Fixture at a Time.
May 28, 2009
Phoenix, Az
A few hot lights around the pit opening should suppress the fog.
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Dan Fischer

Nov 6, 2015
Rochester, NY
I agree with using fog chillers. Normally you want fast dissipating fog fluid with a chiller because when the fog is cooled it will hang longer. I’d try using standard fog fluid as well as fast dissipating fog fluid to see what works better. The standard fluid should hang even longer but you’ll want it really cold. Make sure to use dry ice in the chiller as it gets it much colder than water ice. Also the quality of the fluid matters a lot! We only use Ultratec or Froggys Fog fluids. Stay away from the cheap fluids. They don’t work well for this.

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