creating a screen of fog
- Thread starterinnovation88
- Start date
If you´re doing indoors in a space where you can shut off the aircondition/ventilation, you can try this: Use CO smoke and lead it into a pipe with holes drilled in a row on the underside. The pipe can´t be too long, ours was about 2m. The size of the holes you have try out. If you can use a compressor to press the smoke into the pipe the holes can be smaller, creating a thinner wall of fog. We didn´t use a compressor and the size of the holes was about 10mm in diameter. The distance between the holes were about 5cm. We didn´t use this with a back projection, but it worked fine with frontprojection.
innovation88
Member
My guess is that the "CO" smoke is really "CO2" (or dry ice fog). It can be used with a chemical fog generator or with heated water; a blower motor makes both work much better.
Of course, I'm thinking that you want this to be a fairly large veil to project onto. Might I suggest the use of a scrim with piped dry ice fog from above to give the illusion of a veil of fog? That would give a more consistent layer that would look "phantom" like.
Again, use of one of these Home Depot blower motors that are typically sold as floor fan units (our custodians use them to dry wet or waxed floors) really adds in allowing the fog to be forced out of the pipe. I would recommend at least a 3 in pvc pipe with holes drilled in it (probably 5/8 or 3/4 " holes). Use flexible plastic dryer vent pipe duct taped to the blower motor fan to transmit the pressure.
Hope this helps.
Of course, I'm thinking that you want this to be a fairly large veil to project onto. Might I suggest the use of a scrim with piped dry ice fog from above to give the illusion of a veil of fog? That would give a more consistent layer that would look "phantom" like.
Again, use of one of these Home Depot blower motors that are typically sold as floor fan units (our custodians use them to dry wet or waxed floors) really adds in allowing the fog to be forced out of the pipe. I would recommend at least a 3 in pvc pipe with holes drilled in it (probably 5/8 or 3/4 " holes). Use flexible plastic dryer vent pipe duct taped to the blower motor fan to transmit the pressure.
Hope this helps.
zuixro
Active Member
Dalamar
Member
Needing a blower, fan or forcing air into a conduit of any kind is a general misconception for creating fog walls with Low-Lying Fog.
a) Forced gas (air, CO2, N2..) into a conduit increases pressure. That’s a given. Increasing pressure augments temperature… on cold fog. That defeats the purpose.
b) Forced gas into a conduit creates turbulence. Turbulence breaks down the fog, reduces its density and, ultimately, becomes too thin to reflect sufficient light. Defeats the purpose, too.
What you need to do is use an ICE FOG Q, split conduits to each end of an isolated recipient, as long as required (no more than ~20’), let it fill with fog (which will settle and densify) and let the overflow fall off. The sheer pressure form the liquid refrigerated CO2 will be ample push for your purpose. Even then, the fog falling off will tend to expand as it warms up, so the lower wall will not be as straight as the top.
Also, front projection will give you higher image intelligibility than rear, which will create a “ghost-like” result.
For further help/ tips, contact me at the office.
a) Forced gas (air, CO2, N2..) into a conduit increases pressure. That’s a given. Increasing pressure augments temperature… on cold fog. That defeats the purpose.
b) Forced gas into a conduit creates turbulence. Turbulence breaks down the fog, reduces its density and, ultimately, becomes too thin to reflect sufficient light. Defeats the purpose, too.
What you need to do is use an ICE FOG Q, split conduits to each end of an isolated recipient, as long as required (no more than ~20’), let it fill with fog (which will settle and densify) and let the overflow fall off. The sheer pressure form the liquid refrigerated CO2 will be ample push for your purpose. Even then, the fog falling off will tend to expand as it warms up, so the lower wall will not be as straight as the top.
Also, front projection will give you higher image intelligibility than rear, which will create a “ghost-like” result.
For further help/ tips, contact me at the office.
my understanding is that fogscreen uses an ultrasonic water based system, not unlike in concept the units that are sold for misting plants
Ultrasonic Water Fogger-The Mist Maker
Obviously the fogscreen uses a setup where there is more control, but it is actually just plain water
Sharyn
Ultrasonic Water Fogger-The Mist Maker
Obviously the fogscreen uses a setup where there is more control, but it is actually just plain water
Sharyn
