To start with, let’s make it clear as to what smoke is and the difference between smoke and a smoke-like effect. Real smoke contains tiny solid particles such as soot that make it harmful to breathe. Whereas smoke effects create tiny liquid droplets suspended in the air that give the illusion of smoke. For this reason, we shall call it fog as it is a dense and opaque moisture cloud.
Coming back to the difference between haze and fog, there is a lot of confusion when it comes to selecting a hazer or fog machine, they both have completely different jobs but often the terminology gets mixed up and it can lead to a venue saying no to its use which can have a detrimental impact on your event! In this blog, we are going to highlight a few key differences between haze and fog, one being able to enhance the effect of lighting features while the other creates a thick barrier that can disorientate and disguise for effect.
So what does a Haze Machine do?
Haze is the name given to a vapour that disperses throughout a space to create a subtle mask in the air. When lit it will highlight beams of light and colour. It’s used on nearly every event with professional lighting and in nearly every nightclub in town. It’s normally odourless but sometimes comes with funky scents like “apple blossom” or “pine trees” (or pretty much anything you could find for your car air freshener).
The key, to using haze is not to use too much. Under normal lighting, it should be barely noticeable. It’s meant to be subtle rather than thick. True, you can see the beams of light better when the room is completely saturated in haze but you also start to struggle to see 5ft in front of your own face if it gets too thick. (This tends to work to the dirty nightclubs advantage!) Haze has a long “hang time” where (provided the doors aren’t wide open creating a draft) it will remain in the air for a long time after it’s been pumped out of the machine.
Haze is typically created using a water-soluble glycol or highly refined oil-based fluid by using heating elements or compressed CO2 to vaporize the fluid. This cloud is then pushed out of the machine using a fan within the haze machine to disperse the vaporized particles. In most haze machines, the haze can be created almost as soon as you plug the machine in as the small heating elements heat up quickly to be able to produce the effect. The hazers that require compression can be fairly noisy as they have a built-in compressor.
It is advisable to isolate any smoke detector fire alarms within the room in which you will be using the hazer as although it shouldn’t, sensitive alarm systems could be triggered if the haze gets too dense. The key thing to remember with haze is there is no heat or smoke, it is water-based vapour that leaves no residue once it’s disappeared.
What Does a Fog Machine Do?
Fog machines create a thick white (or sometimes coloured) smoke which makes it more of a special effect and is very effective at obscuring the audience’s vision leading to a dramatic reveal or as often used in theatrical performances, to replicate the effect of a fire.
A Fog machine works by pumping special fluid into a heat exchanger that boils the fluid into its gas form before pushing it out of the machine under high pressure creating a dry, dense cloud that billows from the machine. Because the fog is heated, it won’t stay close to the ground, instead, it generally rises into the air and begins to cool. As it cools it disappears which makes it short-lived yet impressive effect. Once a cloud of smoke has been produced it will move with the general airflow. It can be controlled to some extent by using fans but generally, it will go wherever the breeze takes it!
There are some fog machines that use aerosol cans for the fluid and propellant so that you can create plumes of fog without the need of having a permanent power source. When using fog it is also advisable to isolate any smoke detecting fire alarms as the fog generated will set off a detector leading to an unwanted evacuation.
When should I use a haze machine?
Haze is used a lot during events that require creative or colourful lighting such as music events or awards ceremonies as it is unobtrusive and doesn’t obscure the audience’s view of the stage but offers a great atmosphere at the event. It adds an extra dimension to lighting effects as the beams can be seen in mid-air. You can see our haze machines here.
When should I use a fog machine?
Fog machines create a smoke effect. They are most effective in theatre, TV dramas and occasionally for music and live events where smoke is suitable. They are commonly used in homes for Halloween and can be cheaper to buy and run than haze machines.
What do you get if you cross a Fog Machine with a Hazer?
The answer is a Fazer! It’s a new breed of machine which can replicate many aspects of both a fog machine and a hazer. They are a bit of a compromise so generally produce a haze type effect but is not as fine and long-lasting as a good hazer.