Fire Suppression Systems


A commercial fire suppression system

Ahern is your single-source provider for all of your fire suppression system needs. From basic design, installation, and service to complex specialized systems, we have the NICET-certified designers, in-house fabrication resources, and experienced field teams to meet your project needs. Our Special Hazards Department specializes in fire suppression and detection using non-water based systems, to protect mission critical equipment and data. Ahern designs, installs, and services the following partial list of fire suppression systems. If you don't see the system you're looking for, please contact us for further information.

Ahern also offers services for Fire Protection Inspection, Fire Equipment/Life Safety and Fire Protection for Special Hazards in existing buildings.

Fire Sprinkler Technology

A deluge sprinkler system refers to open sprinkler heads attached to system piping. The system is activated through a separate detection system. Following system activation, water will discharge from all sprinkler heads. Deluge systems are installed to protection high-hazard areas, such as aircraft hangers.

Dry pipe fire sprinkler systems refer to sprinkler heads attached to piping containing a gas (nitrogen or air) under pressure. Following system activation, the gas will be expelled and allow water to travel through the system piping to the affected areas and control fire growth. Dry pipe sprinkler systems are commonly installed in areas subject to freezing temperatures.

Fire pumps are utilized to boost the water pressure for use with sprinkler systems.

Preaction sprinkler systems refer to sprinkler heads attached to piping containing a gas (nitrogen or air) under pressure with a separate detection system. Since two trigger conditions need to occur before activation, this type of system is used when water damage from false system activation could cause significant or non-repairable property damage.

Piping installed on private property that supplies sprinkler systems, private tanks, or private fire hydrants. This piping may or may not be buried underground.

The Quell Design Method was created by Tyco Fire Protection Products to protect cold storage warehouses. This method is desirable to these facilities because it eliminates the need for in-rack fire sprinklers.

Standpipe systems are an arrangement of piping that supply fire hose connections installed in high-rise buildings.

Wet pipe fire sprinkler systems are the most common type of fire protection system. Wet pipe refers to sprinkler heads attached to piping containing water, that when activated will immediately begin to control fire growth. Contrary to movie depictions, fire sprinklers for these systems do not all activate simultaneously; only sprinklers covering a high heat area will activate.

Fire Alarm and Control Technology

Conventional fire detection and control systems provide the basic functions needed for most fire protection scenarios. Early units were very rudimentary in their function, as they typically used relay logic. Today, through integrated circuitry, they contain single board processors to provide input and output logic. They are not as versatile as the Intelligent type of panel, but do have limited modification to their logic through predefined function modes. All input and output devices are contact style or yes/no style units, thus they are not classified as Intelligent. This allows for any brand of device matching the parameters of panel circuitry be used for replacement.

Intelligent fire detection and control systems get their name from the fact that they contain a processing system or on-board processor. This processor is uploaded with a defined set of actions to make the system perform output functions based on a defined input. To keep the systems operating within the requirements and parameters of NFPA codes and UL Listing, there are limits set to how, what, and when these functions happen. In general, they are less customizable than a typical process control system due to the life safety factors of their function. These units can function as stand-alone fire alarm systems, release suppression agents or systems, and provide fire detection and control to protect critical spaces and equipment. Input and output through analog Intelligent devices allow communication to the processor through a dedicated circuit using proprietary protocols between each device. This communication requires devices matching the processors protocols be used when replacing devices.

Fire Detection Technology

Air Sampling Smoke Detection (ASSD) is also known as High Sensitivity Smoke Detection (HSSD) or Very Early Warning Smoke Detection. This type of fire detection system works by actively drawing air through a piping or tubing system to a centrally located detection assembly. The principle of the detection unit is very similar to a traditional smoke detector, which uses a light source projected across a small box and measures how much of the known amount of light is scattered or not allowed to pass to the other side of the box. By utilizing higher end light sources, such as multi-spectrum lasers, and more sophisticated light measuring devices, these units go beyond seeing the smoke. They can also determine the smoke color and particle sizes, as well as discriminate between dust, dirt, and smoke. Using these high-tech components along with data modeling and learning components, these systems can be programmed to be up to 1000 times more sensitive than traditional smoke detectors. This allows for warning of a prefire condition, which gives personnel time to investigate or correct the situation before smoke, heat, and flame can damage the protected property.

Analog intelligent smoke detectors look like typical smoke detectors; however, they are designed to report their information to an addressable fire detection panel. Where a traditional spot type smoke detector can only interpret a preset volume of smoke exceeding a set point, an analog intelligent detector can send the panel data beyond ‘on’ or ‘off.’ The detector can also be given a unique identifier so the fire panel can interpret not only the condition and state of the detector, but also exactly which unit is reporting its information to the fire panel.

Gas detection systems are electronic devices designed to detect various types of combustible or toxic vapors. Common uses are the detection of vapors from cleaning solvents; fuel and other hydrocarbons; ammonia; carbon monoxide; and other poisonous vapors.

Most units utilize an electronic element calibrated to change state as an amount of product vapor is introduced to the point at where the detection unit is placed. This detection element’s change of state is interpreted by a small controller that can then provide a digital readout, dry contacts, or 4-20 milliamp output for integration into process control or building automation systems. Today, the more high tech units measure changes in wavelength transmission of a beam of infrared light across a small detection chamber to determine an amount of vapor near the detection unit. This provides a more robust unit capable of being washed or flooded without causing permanent failure.

Basic linear heat detection is designed to detect a fire through heat buildup from a fire event. Most systems work on the principal of a pair of wire conductors separated by a membrane that will melt at a defined temperature. This allows the wires to come in contact with each other, which causes an alarm. This wire bundle is then wrapped in various types of outer jackets, depending on the environment the wire will be used in.

Although this system can be used in any application requiring heat detection, typical applications include interiors of electrical cabinets, tunnels, freezer and refrigerated warehouses, aircraft hangers, and many other large areas. Ease of installation makes this system ideal of large areas requiring cost effective fire detection.

Today, these systems simulate the twisted wires with fiber optic cable. By measuring the changes in the way light transmits through a fiber optic cable, an exact temperature at a precise point over the fiber optic cable can be interpreted into an alarm.

Optical flame detection utilizes electronic detection assemblies measuring a spectrum of light that can in turn be interpreted by on-board processors or controllers. By comparing the spectrum, intensity, and flicker or pulsing of the light, and processing it with a program of manufacturer algorithms, it can be compared to a known signature of a type of flame. The processor will then trigger an alarm or action. Many of the original flame detection technologies were prone to false alarms caused by other types of light that looked similar to the flame the unit was designed to see. The lack of intelligence or processor technology limited these original units. There is little comparison of today’s technology and those of years past.

Video Image Fire Detection is the newest technology to be added to the fire detection technology options list. At its simplest form, think of the way your eyes see flame or smoke. You see an image, which is interpreted by your brain based on past knowledge and learning from previous situations. From that data, you make a determination of what action to take. These systems analyze each pixel of a video camera’s digital image, and compare them to a base image using manufacturer algorithms to determine differences. Actions can be programmed to create warnings and alarms. Not to be confused with optical flame detectors or beam type smoke detectors, these units are truly utilizing the full visual image - not just electronically analyzing them for a spectrum of light specific to a flame. The advantage of these systems over other detection technology is the ability to have a recorded history of the video image. This video image can be marked, tagged, flagged, stored, archived, and played back. It can also be remotely viewed over the internet or sent to smart phones. The best units are approved by Factory Mutual; UL Listed, and meet all requirements of NFPA 72 for fire detection devices.

Fire Suppression Technology

Argon suppression is similar to other inert gas clean agents such as Argonite, Proinert, or Inergen, except it is not a blend of gases. Argon’s advantage is that it is truly inert and does not react with most combustible elements. It is very effective on burning metals, and is one of the few products that can suppress a fire of that nature.

These suppression agents are systems designed around naturally occurring atmospheric gases, and are classified as Inert Gas Clean Agent Systems. Argonite from Kidde and Proinert from Fike are a blend of Argon and Nitrogen. Inergen from Ansul is a blend of Argon, Nitrogen, and a small amount of Carbon Dioxide. These critical blends are designed to suppress a fire by reducing the oxygen in the protected space to a level that will not support combustion but still allows occupants to breathe. They take advantage of the body’s ability to recognize a low oxygen environment, much like being at a high elevation, and raise the respiration rate to draw in more air volume containing low quantities of oxygen. This small detail makes the design of these systems critical to maintain the window of life safety.

As Argointe, Proinert, and Inergen gas blends cannot be compressed into liquid format, they are required to be stored in high pressure spun steel cylinders. As such, they require several cylinders of agent to displace the required volume of natural atmosphere in a protected space.

Explosion protection systems are a product line many will never deal with or even knew existed. Explosion risk is present with many industrial process facilities involving food, grain, pharmaceuticals, power generation, aerosol filling, wood, or other flammable vapors or combustible dusts in confined vessels or spaces. These sophisticated systems are designed to detect an event within milliseconds by watching for either a flame, with high speed optical flame detectors, or the pressure wave in front of the flame with pressure detectors. By rapidly injecting a suppression agent into the space or volume, the heat is removed from the flame front as it consumes the fuel, thus stopping the event.

Other methods of dealing with explosion risks are venting of explosion pressures and flame to a safe area outside via explosion relief vents; containing explosion pressures with vessels capable of withstanding the expected pressures; or isolating the explosion pressure and flame with special dampers and isolation valves.

F-500 is a multi-purpose, Micelle Encapsulator Fire Suppression agent that is used worldwide for various applications. The fire suppression mechanics and technology utilized by F-500 are vastly different than conventional foam. F-500 forms and maintains micelles, "chemical cocoons," around the hydrocarbon fuel to neutralize the fuel leg of the fire tetrahedron rather than forming a blanket depriving the fire of oxygen. Typical uses are fire suppression of flammable liquids, coal, tires, and other rubber products that would typically create difficult-to-fight fire situations. It can be applied via a special sprinkler system, added to hose streams, or manually sprayed via premixed spray tanks of agent and water.

F-500 Encapsulator Agent has been proven in the field, and tested by numerous certification and regulatory agencies around the world.

FE-13 (Trifluromethane), or HFC-23, is a product of DuPont. It is primarily used as a total flooding clean fire suppression agent in industrial situations where large volumes, changing volumes, or low temperatures are involved. It functions as a fire suppressant similar to that of FM-200, FE-25, or Novec in that it is stored as a liquid under pressure and flashes to vapor upon discharge. Its fire suppression is mainly a function of cooling.

FE-13’s biggest advantage is its naturally higher vapor pressure. This allows for suppression in applications as low as -40˚F, and in areas where nozzle heights to 25 feet are beneficial. This high vapor pressure also requires that the agent be stored in high-pressure cylinders, making them different than those of the other fluorinated agents. It does have a higher Atmospheric Lifetime than the other agents, but still has Zero Ozone Depleting Potential. As with all of today’s new clean agents, it has been approved for applications in occupied areas, and is safe for humans.

FE-25 (Pentafluoroethane), or FE-125, is a DuPont product that is similar to the other fluorinated agents (FM-200, FE-13, and Novec 1230). It suppresses a fire primarily via cooling, as it has a massive ability to absorb heat as it flashes from a liquid to a vapor in the protected space. It is approved for occupied areas, is safe for humans, and has Zero Ozone Depleting Potential. With a slightly higher natural vapor pressure than FM-200, FE-25 is an ideal retrofit agent to Halon 1301 systems.

FM-200 (Heptafluoropropane, HFC-227 or HFC-227ea) , the first commercially viable clean agent alternative to Halon 1301, was introduced in the early 1990's, and has since become synonymous by many for the entire family of clean agent fire suppression. FM-200 mainly suppresses fire through cooling (see Fire Triangle), as it is also from the refrigerant family of chemicals. It is stored as a liquid under pressure, and instantly flashes to vapor when discharged into a room. It does not remove oxygen from the space, other than the small amount of normal air displaced from the room. It has been tested and approved as safe for people (occupied spaces) when properly designed. 

Foam fire suppression agent has a long history with many methods of application. There are various types of agent compounds, all work by using a wetting agent or surfactant to create a blanket of bubbles that can separate the fuel and oxygen, as well as cool the source of heat. Some types of Class A foams work on the theory of allowing water to penetrate easier and deeper into wood, paper, or other products to stop a fire event.

Foam systems are typically classified as low expansion (under 20:1 expansion), medium expansion (20-200:1), or high expansion (over 200:1). A newer addition to the foam family is CAF or Compressed Air Foam. This product introduces a compressed air stream into a mix of foam agent and water to create a foam stream with the dry consistency of shaving cream. This specialized type of foam is well suited to dimensional fires, as its dry consistency allows it to cling to vertical surfaces.

Foam systems can be integrated into fixed sprinkler systems, fixed spray nozzles, fire hose streams, or introduced into a space by special foam-making equipment designed just for the purpose of making large quantities of foam.

Halon 1301 [Bromotrifluromethane] was considered the first clean agent fire suppression product commercially utilized as an alternative to fire sprinklers and carbon dioxide. Halon 1301 has been mainly used to protect high value assets, and has found its way into many applications where water-based fire protection is not desired. Contrary to popular myth, Halon is safe for people. It does not “suck the oxygen out of the space or your lungs.” Halon 1301 mainly stops a fire by breaking the way oxygen and carbon (fuel) molecules come together. As it is from a family of chemicals used for refrigerants, it also has the ability to remove heat (see Fire Triangle). Because Halon is a Chlorofluorocarbon (CFC, an ozone depleater), production of new Halon ceased in 1994. There are no cost-effective methods for safely and effectively disposing of Halon. Therefore, recycling and reusing the existing supply is recommended. Systems in good functioning order are still allowed to be recharged in most U.S. locations.

Carbon Dioxide is considered by many to be the original clean agent. First used for fire protection in the 1940’s, it is a colorless, odorless, non-corrosive, and non-conductive inert gas. It suppresses a fire through oxygen displacement and a small amount of cooling as the liquid flashes to vapor. Its biggest detraction is the fact that when large quantities are taken into the lungs, it is an asphyxiant or inhalation hazard, blocking oxygen from being absorbed by the bloodstream.

High pressure CO2 is stored as a pressurized liquid in a spun steel cylinder. By keeping the agent at 850 psi at 70˚F, it remains a liquid without any additional equipment or systems.

Ideal for suppression of fires with most types of combustibles or flammables, most applications today are industrial process and equipment protection, where the space is either unoccupied or unoccupiable.

Industrial Dry Chemical fire suppression systems are the larger cousin of the standard portable fire extinguisher. Utilizing the same types of dry chemical powders found in typical fire extinguishers, they are designed and engineered to apply the agent to the fire via a network of pipes and nozzles.

When integrated with a detection system, they can automatically actuate to suppress a fire event.

The powders used include Sodium Bicarbonate, Monoammonium Phosphate, Potassium Bicarbonate with the type being determined by the fuel to be suppressed.

Typical applications for the systems are flammable liquid storage buildings, fuel loading truck racks, and pumping facilities where the volume of water necessary for a foam water sprinkler system is not available.

Low pressure CO2 has all of the same fire suppression characteristics as high pressure CO2, with the exception that it is stored in an insulated, refrigerated vessel to keep the product in liquid state. The target internal pressure for the vessel is 300 PSI. Agent storage units range in size from 750 pounds to 50 tons of liquid weight. This large volume of agent storage and low cost of refill via direct bulk truck delivery, make it ideal for protecting multiple hazards or hazards requiring large quantities of CO2. These systems can also be used to provide constant inerting of process or storage vessels to maintain a low oxygen atmosphere non-conducive to fire.

Novec 1230 (Pentafluoroethyl ketone) is a clean agent developed by 3M. Its use and function as a fire suppressant are similar to that of FM-200 or FE-25, in that cooling is its primary method of suppression.

The product has zero ozone depleting potential, and has a Global Warming Potential of 1 – a level below that of other fluorinated agents.

Spark/Ember Suppression systems are typically used to stop small sparks and embers traveling in industrial ducts used to carry flammable dusts and materials to processes or filters and collection equipment.

Working with a system of very sensitive optical sensors and water spray assemblies within the ducts, the small glowing embers or sparks are detected as they travel down the duct or pipe in the airstream. Before they can make their way to the process or filter, a curtain of fine water is injected into the duct or pipe to quench and remove the heat or energy from the particles. The systems are designed to cycle on and off as needed, only stopping the process when excessive quantities of sparks or embers are seen. The systems are designed to remove the sources of energy, as a preemptive strike that could result in a fire event or explosion if not addressed.

Watermist systems are one of the newer methods of fire suppression utilizing water. What differentiates these from standard fire sprinkler systems is the water droplet size and volume of water needed for fire suppression. By breaking the water into smaller droplets, the water has a greater ability to absorb heat quickly. As the water turns to steam instantly upon hitting a flame, there is also the residual effect of some oxygen displacement from the fuel and the general wetting effects on objects that have not become involved in the fire situation. Being able to suppress a fire with very little water, the systems are ideal for critical spaces, flammable liquid spaces, equipment spaces, and even light hazard spaces such as hotels and offices where limiting damage from large volumes of water can offset the added costs associated with the watermist.

These systems can be broken into two major categories of either Single Flow or Twin Flow. Single Flow systems consist of a single piping network feeding special nozzles with a high-pressure stream of water that is pressurized by either pumps or high-pressure nitrogen. Twin Flow systems utilize a separate pipe network for the water at a low pressure and high pressure inert gas. These networks are combined at the nozzle to atomize the water into a stream of fine droplets and inert gas, typically nitrogen. Both types of systems can be supplied water either by a potable continuous source or via pressure tanks holding a finite water supply. Systems are manufactured by many fire equipment providers.

Each system has various pros and cons relating to the following attributes: droplet size, operating pressure, piping types and complexities, nozzle layouts, pumping or pressurizing methods, and listings or approvals for certain applications.

Fire Equipment

Emergency lights are connected to a backup power source (battery or generator) for use during power outages. Emergency lighting will include all illuminating lights for path of egress, as well as illuminated exit signage. Typically these lights will be located in occupant areas, such as hallway commons, bathrooms, confined spaces, computer rooms, equipment rooms, etc. Windows do not eliminate the need for illumination, due to the fact occupants may be on site after day light hours.

Fire extinguishers are a supplemental form or first aid extinguishing tool, used to extinguish small fires. Fire extinguishers are placed throughout a building for small first response situations. They are not intended for firefighting applications.

Kitchen hood systems are mechanical pre-engineered wet chemical systems that work in conjunction with equipment for the removal of smoke and grease laden vapors. Kitchen hood systems are designed to provide fire protection for cooking appliances, hoods, and ducts. These systems have two ways to release the agent: manual operation or automatic actuation. The detection designed by the manufactures for these systems, heat detection, will automatically release at a pre-determined heat range; however, it is recommended that if there is a fire on an appliance, the first action taken is to pull the manual pull to release agent, and also shut down all fuel sources. The system suppresses fire by spraying the plenum area, filters, cooking surfaces, and exhaust duct with a low PH solution that will cool and extinguish the fire. The agent will also saponify, or foam up, to create an insulation barrier between the hot grease and air, thus helping to prevent the escape of combustible vapors.

This range or system design includes small industrial dry chemical systems that have been designed to protect industrial applications categorized as local application, tank side, total flooding, vehicle, and open front spray booths. The system is a pre-engineered design having predetermined flow rates, nozzle pressures, and quantities of dry chemical, or flow rates. The system is self-contained and uses dry chemical agents for fire suppression. The automatic activation of the system has three variations of release: mechanical release, pneumatic release, and electric release. The system can be released or actuated manually or automatically. Each system has a manual pull station for discharge.

Vehicle systems are designed for use on mobile and self-propelled equipment such as earth moving, land cleaning, forestry, farming, buses, and collection vehicles, to name a few. These systems are available in dry chemical and wet chemical suppression agents for extinguishing fires on mobile equipment. The system is designed with electric detection and actuation. System design works on a total flood application of hazards identified on each specific piece of equipment. The system has capability to operate in extreme weather and environment conditions that range from -65˚F to upwards of 140˚F.

While Knutson has partnered with Ahern in the past, this was my first project working with their team, and they've definitely exceeded my expectations. This project had a very aggressive schedule. Ahern's team did a good job not only catching up early on, but keeping up with the job moving forward as well. The biggest thing that's stood out to me with Ahern is their ability to quickly identify and discuss potential problems. Working in an existing facility, they were good at making us aware of building issues right away. They've shown great communication and technical knowledge, which was very beneficial to the job.

Ryan Rydberg

Project Engineer

Knutson Construction

Ahern was instrumental in bringing this project in on time and to budget for our company... We could not be more pleased with the way Ahern managed this project for our company.

Steve Peterson


Mid-States Aluminum

Ahern did an outstanding job getting our project completed and operational under what were, at times, very adverse conditions. The team installed pipe during winter weather of -40˚F, and handled all the accompanying challenges effectively.

Jack Williams

Vice President of Operations

Central Storage & Warehouse Company

The staff at Ahern was a great asset to have on the team. Permitting and construction issues were tremendously difficult to work through; however, when it came to the fire protection, Ahern was ready to step up to the plate with their skill and knowledge. As a result, this was one area that was easier to work through.

Peter Nemmetz

Project Manager

Design Structures, LLC

Ahern did an outstanding job giving us a high quality job while still maintaining our very tight schedule. They did a great job working within our high standards of safety and being a real team member. They always kept the project goals on the forefront while maintaining their high standard of work. It was a very positive experience working with Ahern.

Curt Schleicher

Project Manager

The Samuels Group

Ahern has consistently provided us with professional, quality workmanship and project management for their portion of our projects. In today’s world of construction where sometimes other contractors come in with a lower price, we have found that we wound up with more headaches and extras, which makes companies such as Ahern a value to any project.

Dan Peters


Peters Construction Services, Inc.

It was critical that the sprinkler system be installed as quickly as possible so that the other trades could continue with their work. Ahern did not disappoint us. Their layout, fab work ,and installation were completed as they promised, when they promised. It was a great pleasure to work with a Company that devoted so much effort to ALL of the details involved in their work.

Phillip Koesterer

Vice President of Operations

Phoenix Building Group, Inc.

Ahern did a great job on the Flair project and I was impressed with their fire protection code knowledge. The project was completed on schedule, within budget, and without complications.

Kip Golden

Project Manager

Keller, Inc.

Ahern was a pleasure to work with. We were very impressed with the forethought that the team brought to each project meeting. This attention to detail helped to keep the entire project on schedule, and provided a full understanding of what needed to be done. We are very happy with the work that Ahern performed.

Joe Englebert

Project Manager

Portside Builders, Inc.

Ahern performed excellently on our project schedule and cost, while exceeding my expectations in respect to design and coordination with other disciplines for the ESFR Sprinkler Systems. Ahern’s communication was very up-front and thorough throughout the process. I recommend Ahern without any hesitation.

Scott Zola

Senior Project Manager

Clayco Construction