Marioff HI-FOG Water Mist

Marioff HI-FOG Water Mist
HI-FOG Water Mist

HI-FOG, by Marioff, is the world’s leading water mist fire protection technology. HI FOG systems use high pressure to produce a fire water mist with average drop size of 50 – 120um. This ultra-small droplet size increases the fire suppression capabilities while at the same time reduces the amount of water need to suppress a fire significantly. The HI-FOG system is fire protection which is fast, efficient and totally safe for people and the environment, as well as giving virtually cost free clean up or recharging. 
Now a version of HI-FOG has been developed specifically to combat the primary risk associated with fires in computer rooms, telecom exchanges and other areas with sensitive electronic equipment.  Not only will Marioff’s HI-FOG system extinguish any fire, it will also reduce significantly the primary cause of damage to a mission critical facility, SMOKE.

  • Factory Mutual* states that “The use of plastics with varying degrees of fire retardancy for computer or related equipment internals creates the potential for very large amounts of smoke to be produced in the early stages of a fire and can have very damaging effects.”
  • The HI-FOG System, activated at an early stage by a fast acting detection system, effectively scrubs the smoke from the sub-floor, equipment or room, preventing costly contamination and damage to electronic circuits.  Even if the fire is outside the space, the system provides this vital protection.  If there is a fire left it will also extinguish it.
  • An accidental discharge is no danger to equipment or people.  Unlike a gaseous system any dust dislodged will be absorbed rather than spread around the room.
  • The system will operate effectively even if the door is temporarily open, allowing people to safely evacuate or enter the space without harm from the fog.

Room Extinguishing System
Room Extinguishing System
Room Extinguishing System

Room Extinguishing System

  • A well engineered high pressure water mist fire protection system provides superior extinguishing properties, cooling to prevent re-ignition and further damage and radiant  heat absorption to prevent fire spreading. 
  • The HI-FOG Room Extinguishing System consists of ceiling mounted HI-FOG Spray Heads connected to the self-contained water\nitrogen Cylinder Unit.  The system is designed to extinguish fires in the room as well as remove smoke which is absorbed by the fog, falling to the floor for later clean-up.
  • Substitute for pre-action/double interlock sprinklers,
  • Or used in conjunction with sprinklers.
  • HI-FOG is a Class I (NFPA 750) water mist which is accepted by the U.S. EPA (Environmental Protection Agency) as being environmentally benign and suitable for use in all manned spaces.

Amount of water used

  • In the FM approved HI-FOG Sub-Floor System a high density water fog is produced in the first 30 seconds.  However, this water is virtually all kept in the scrubbing pipe work, absorbing the smoke, and collecting as waste water in the drain pipe work.  In the second phase, when the fog is being discharged in the sub-floor or room, the same amount is used during the next 10 minutes.  This much finer ‘dry-fog’ provides cooling and extinguishing as well as smoke scrubbing.

Safe for People

  • HI-FOG is totally safe in the event of an accidental discharge, and unlike halocarbon gases, produces no dangerous decomposition products in the event of a fire.  Moreover the smoke scrubbing and absorbing capability mean reduced danger within and outside the protected space.

Safe for equipment

  • HI-FOG systems actually discharge very little water into the sub-floor or the room so no damage is done even to sensitive electronic equipment.  After a discharge the air is quickly dehumidified when the ventilation is restarted.


  • HI-FOG systems are easy to recharge.  Cost of replacement ‘agent’ – water and nitrogen is negligible, unlike a gaseous system.

HI-FOG spray headsHI-FOG spray heads

  • Precision engineered stainless steel spray heads designed for minimum water flow and maximum smoke scrubbing and fire suppression efficiency. 

How does HI-FOG work?

Sprinkler Sprinkler

  • Conventional sprinklers and water spray systems fight fires by the inefficient process of wetting or cooling combustible surfaces.  But HI-FOG, a high pressure mist technology, uses water in the most efficient way, extinguishing by using three primary mechanisms described below.  The combination of the right drop size distribution and high velocity ensures efficient penetration and the rapid cooling of the fire plume and adjacent gases. 


  • Water absorbs more heat (.2 MJ/kg) than any other extinguishing agent when turning to vapour.


  • The atmosphere is locally inerted by displacing oxygen (Water expands >1760 times in volume when vaporized).

Radiant Heat Blocking

  • Small droplets efficiently absorb and scatter the heat radiation.

Marioff HI-FOG Applications
Marioff HI-FOG Applications:

Marioff HI-FOG Applications:

  • Computer rooms, telephone exchange rooms and electrical switchgear rooms
  • Archives and store rooms, especially those containing flammable liquids
  • Machinery space, engine driven generators and turbine protection
  • Transformer protection
  • Oil and gas production facilities for offshore and petrochemical industries
  • Cruise ships, passenger vessels, cargo and other ships
  • Hotels, public and commercial buildings and offices
  • Heritage buildings, museums and archive stores
  • Metro stations and train carriages
  • Traffic tunnels