A: Water based fog machines generally use a mixture of very pure glycol and water as the fog fluid. This fluid is pumped by the machine into a temperature controlled heat exchanger that vaporizes the fluid into thick clouds of fog, projecting it out through a nozzle located at the front of the machine.
A: Wind is a fog machines enemy! The particles that make up the fog are very small, 1 to 2 microns in size, and even a light breeze will quickly disperse the fog as it shoots from the fog machine. Sometimes the fogger can be moved to compensate for wind. There is no guarentee of proper fogging when used outside. But we try our best.
A: Yes, no, maybe! It is possible that the small water-based particles could set some types of smoke detectors off. Usually, this is only a problem with optical type detectors, because they sense these particles as smoke. We always run a test with the fog machine(s) when used indoors to see if this is a problem. We don't recommend disabling smoke detector(s), but if you consider this, you should contact your local fire marshal and insurance company for advise. Sprinkler systems on the other hand are usually triggered by heat, so the fog in the air won't active heat-activated sprinkler systems.