Buy the best fog machine and stop replacing it each year.
Like countless others, you may have bought a couple of fog machines from Spirit only to find that they break faster than a soup cracker in a sandblaster. They never last more than two years, even if you are exceptionally careful about installation and cleanup and storage. Spirit doesn’t give a damn, of course. Google yields thousands of reports from people with the same issue, which basically is a cheaply manufactured pump that you can’t buy anywhere outside of China in quantities of less than a thousand.
How much does a good fog machine cost?
Another good machine is the Chauvet Hurricane 1100 Fog Machine ($100).
Just to give you an idea on price versus quality:
Spirit: 1000W, 5,000 CFM of fog = $79,99
Chauvet 1300: 1300W, 20,000 CFM of fog = $149.99
The Chauvet will also last forever if you take care of it.
There’s a reason why pro grade fog machines cost hundreds of dollars…. they are designed for heavy use and are well built.
Using cheap fog fluid is also the kiss of death for some machines.
Generally the stuff you buy at the local Halloween store is designed to break after one season.
Look at Chauvet, Le Maitre, and Look Solutions for your machines, and Rosco for your fog fluid.
American DJ products are cheap, but would still be a step up from the Spirit lines.
Glycol based foggers tend to produce fog that sits in the air, or rises, depending on the temperature.
Creating Low Lying Fog
If you want a good ground-hugging fog, you can do it in two ways:
1) You could build yourself a dry ice fogger. CO2 fog is heavier than air and will hang on the ground very nicely. You can build a dry ice fogger pretty simply with a steel drum, an immersion heater, some sort of basket for the dry ice, and a computer fan.
2) Chill the glycol fog. You can make a simple chiller for glycol-based fog using an insulated beverage cooler. Cut a hole in either side of the cooler, duct the output of the fogger into one side, and out the other. Fill the cooler with ice, and you’re in business. You can employ a computer fan on the output side of the cooler to help pull the fog thorugh, and give it some “push” out the other side. It takes a bit to fill the ice chest with fog, but once the volume of the chest is filled, you should get a good output out the other side.
One word of warning when using dry ice fog. Since the CO2 vapor is heavier than air, it will displace the air at ground level, and will settle into low-lying areas. Beware of pets and children in low-lying areas, as they might find themselves somewhat oxygen-deprived. Although, outside it is less of a concern than in a stage environment, it bears mentioning nonetheless.