Fog Chillers, Low Lying Fog Machines, Vortex Chillers, Fog Curtains and Halloween Graveyard Fog with Vortex Chillers Low Fog Machines, The World's Most Economical Low Fog. Cold Fusion Cold Fog Ground Fog Halloween Graveyards In order for the fog to stay close to the ground, it must be colder than the surrounding air. You need a fog chiller to do this Economical, free standing chiller units for smoke machines of all sizes....Output can be compared to systems costing many times as much, such as some CO2 low fog systems with operating costs for the chilling system of more than $10 per minute, or $600.00+ per hour on their high settings. The Vortex chilling systems can operate for as little as .3c per minute resulting in up to 20,000% savings over refridgerated systems.