Fog

Fog in the haunting world is a staple and helps add atmosphere as well as acts as a cloak to hide things and enhance lighting effects.

Fog Machines

Mineral Oil Fog Machines

These are the most widely available types of devices to create fog. They work off of a principal of cracking a light mineral oil by heating it up - much like dripping water onto a hot skillet, the fog juice is pumped through a heating element which then vaporizes the mineral oil and produces a white cloud of fog. These types of machines are inexpensive to run and easy and safe to operate. They are rated by wattage of the heating element.

Haze machines

These type of machines tend to run constantly in the background of a stage performance to produce a diffuse haze that helps enhance lighting effects and allows you to see the beams of lights.

Dry Ice

Adding a few pieces of dry ice to a liquid quickly sublimates the dry ice back to its original vaporous form and produces a thick, low lying fog - however the effect quickly dissipates and the dry ice effect only lasts a few minutes. It can also be a suffocation risk if used in enclosed spaces.

Nitrogen

Professional level equipment is required to use liquid Nitrogen as a fog element and is outside the realm of the home haunter. These are the types of devices that produce stage covering, low lying fog in rock concerts and plays.

Misters

These are small piezo electric disks that, when submerged in water, can produce a water vapor fog. They tend to be more expensive and highly dependent on ambient humidity levels to produce the desired effect. These are the types of devices often seen in small desktop waterfalls.