Smoke Machines Vs. Hazers

There are a variety of smoke machines and hazers available on the market.  What are the advantages and disadvantages of the two types?  Which is best for laser shows?  This article attempts to provide answers based on both theory and field experience.

Smoke machines and hazers are important to laserist as light is invisible to the eye.  What the eye sees is the reflection of light from surfaces.  In order to create spectacular laser beam effects, we need particulate matter in the air in order to reflect or scatter the light towards the viewer's eyes.

Definitions

We should start by defining our terms.  Smoke machines are defined as machines that operate using water based smoke fluids.  Common examples are the Rosco, Gem, American DJ, Lightwave, AquaFog and other similar types.  These are very common, popular and usually low priced.

Hazers, also sometimes called crackers, use oil based fluids and some form of compressed gas to force it through a fine nozzle or nozzles thus 'cracking' the fluid into very small particles. Common examples are the MDG machines, DF50, Compass and other similar types.  These types of machines are less common and tend to be more costly.

Smoke Machines

Smoke machines generally operate by pumping the water based smoke fluid, usually with an electrical pump, into a heated evaporation chamber.  Here the fluid is evaporated and ejected from the nozzle at the front of the machine.  What comes out is a thick cloud of white 'smoke' which consists mostly of water vapour and some carbonized particles from the smoke fluid.  Typical particle size in the smoke are 150 microns or more.

Since the output contains lots of water vapour, this adds to the humidity in the room which can cause increased condensation on cold plates and inside the head of water cooled laser systems.

Hazers

Hazers operate by using a compressed gas, commonly CO2 or compressed air, to force the oil based fluid through a very fine nozzle (or nozzles).  This breaks the fluid down into very fine particles.  In some systems, those particles are then sent through a heated evaporation chamber, while in others, a fan is used to blow the particles directly into the air. What comes out is usually a very find haze or a cloud of white 'smoke' which typically has particle sizes in the 5-10 micron range. The output rarely contains water vapour so hazers do not add to the humidity in the venue.

Particle Size

Particle size is an important consideration as we shall see.  Most smoke machines using water based fluids pump out vast clouds of smoke that look impressive. The size of the particles in this smoke are usually over 50 microns and often even larger.  These particles 'clump' in the air forming heavier clumps that soon fall to the ground. This is why you have to have to use frequent blasts of smoke from water based machines to keep up the haze levels - not enough small particles are produced. The cloud of dense smoke often blocks the laser beams absorbing power and cutting down on the effect the audience sees until the smoke disperses.

Hazers produce particles in the under 10 micron range, typically around 5 microns. These particles also clump but produce smaller clumps.  Since the particles are smaller to start with, it takes much longer for the larger clumps to reach critical mass and fall to the floor.  The smaller particle sizes make a fine haze - perfect for laser shows. The fine haze spreads evenly making the laser beams highly visible without absorbing all of the laser power.

Hang Time

An important consideration for laserists is 'hang time' or how long the particles stay suspended in the air.  As mentioned above, larger particle fall to the ground rapidly necessitating frequent bursts of smoke from water based machines to replenish them.  Hazers produce very fine particles that hang in the air four or five times longer then those typically produced by water based machines. A 30 second burst of smoke from an MDG machine will remain suspended in the air far longer than a 30 second burst of smoke from the typical water based smoke machine.

Dispersal

The smoke or haze from a hazer disperses rapidly and evenly through the room producing a fine almost invisible haze, while water based smoke tends to produce a large clouds that dissipates rapidly . You can blow the smoke from a hazer directly into an air-conditioner intake; the particles are so fine that most of the haze will be be redistributed by the air system. If you do this with water based machines, most of the particles will be trapped in the filters and very little is re-circulated.

Fire Alarms

Most water based smoke machines also emit significant amounts of carbon particles from burning that takes place in the evaporation chamber. The carbon particles can trigger smoke detectors and fire alarms causing havoc at shows and ill-will from clients.

A clean and well maintained hazer emits almost undetectable levels of carbon. Laserists have successfully used MDG machines at venues equipped with smoke detectors and had plenty of haze for the show with no false fire alarms.

Due to the fine, well dispersed haze produced by hazers, and the long hang time of the haze, they have a clear advantage over water based machines with their thick clouds of smoke and shorter hang time.  However, because hazes often cost considerably more, some opt for the lower cost smoke machines which may not be such a good option .

OUR EQUIPMENT....

HP-2S Haze Machine

(recommended where fire alarm systems are in operation)

 

The HP-2S allows the user to bring their lighting to life whether it is used with a few lights or a full lighting system. The front mounted fan forces the haze to expand while pushing it outwards, this disperses the haze so that the lights can be seen while not being obscured in a cloud of smoke. From ground level, the haze expands upwards to provide effective coverage in any venue. The HP-2S can haze continuously. For timer control there is a simple timer button that controls the duration of haze blasts. Using this function, the interval between blasts is set for 10 seconds and the duration can be set between 3 seconds and 3 minutes by holding the button down for the amount of time desired for each blast.


Features:

Haze Effect Machine
Built in Timer Control
Warm up time: 4 minutes
700 Watt Heater
1500 cu.ft per minute Output
0.8 Litre Tank Capacity

Specification:

Power supply: 240v
Dimensions: 526 x 207 x 173mm
Weight: 10.0kgs

DOWNLOAD HP-2S FLUID SAFETY DATA SHEET HERE

 Chauvet Hurricane 650 Smoke Machine

(not recommended where fire alarms are fitted)

The Hurricaneâ„¢ foggers by CHAUVET combine reliability, performance, and value into one package.

Each machine features a fluid level indicator located on the front of the unit, and comes with a specific heater, fluid capacity, and wired remote that is particular to the ordered unit.

 

DOWNLOAD Chauvet Hurricane 650  FLUID DATA SHEET HERE