# Fog still too difuse, not chilled enough?



## Caustic (Oct 16, 2012)

For last night's Halloween, I set up my fog chiller with about 20 lbs of ice. It started out as low to the ground, but as the night when on (and the fog machine got hotter?), the fog became increasingly difuse and billowing - not the effect I wanted of course.

So how do I maintain low-lying fog? Should I add more ice to chill it further?

I built my chiller from the 



. I don't have the specific model fogger with me right now, but it's a medium-sized model from Spirit and puts out a decent amount of fog.


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## Hippofeet (Nov 26, 2012)

The fog machine shouldn't be getting hotter. I would say the air temperature went down, and so there was less of a difference between the chilled fog and the ambient air. Not much, if anything, you can do about that. 

More ice might help, slowing down the fog moving through the ice might help, adding salt to keep the ice colder and intact longer might help.

I've had the same problem before, and I never did get it just where I wanted it. S'why some people (like the photography studio next door) still use dry ice. It's just colder, and less influenced by temperature changes throughout the day.


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## corey872 (Jan 10, 2010)

Several things can happen which make fog not stick to the ground as well. Lower outside air temp, higher humidity, less ice left in the chiller, tunnels or holes in the ice which allow fog to bypass can all cause the fog to 'stick' to the ground less.

More ice and keeping it evenly dispersed are easy to fix. But ultimately, you're up against the laws of physics with temperature. With ice, the best you can get is 32ºF air coming out of the chiller. So as outdoor temps fall into the 60's, 50's, and 40's there isn't much difference in fog temp to make it stick. Some have reported adding some dry ice to the chiller. Never tried that myself. 

I guess the other thing to keep in mind, that super low lying fog is really only a movie prop, you don't see that so much in nature. So even if your fog lifts some, it's a lot more natural than a 3" layer hugging the ground.


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## Caustic (Oct 16, 2012)

Aha! I didn't even think about the ambient air temperature, thank you! It was about 58 degrees by the end of the night, so that may have caused the billowing. I'll have to try more ice or perhaps dry ice.


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## goneferal (Sep 8, 2010)

I agree with corey872, the colder it gets out, the less your fog will stay low.


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## RoxyBlue (Oct 6, 2008)

We've found that adding some dry ice to the mix helps, but low ambient temperatures and wind are not your friends when it comes to fog.


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## ATLfun (Oct 12, 2012)

IMO, you need to add more ice and a box of ice cream salt/rock salt. My cooler chiller holds 60lbs of ice and after the first two hours I added 20lbs more.

You can find ice cream salt at any grocery store, just spread it evenly over the top of the ice. I know it sounds like an oxymoron, but the rock salt keeps the ice frozen longer and lowers the freezing temperature. In ice cream making, the rock salt lowers the ice temperature to near zero since milk does not freeze at 32 degrees. (Science Channel-source.)


Warning: table salt cause it to melt faster, do not use.


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