Extinguishing forest fire.Firefighter extinguishes a fire.Extinguishing the fire. Fill the foam with a fire. Resolute firefighters.

Fire suppression systems are activated by heat, smoke, or a combination of the two.
Because suppression systems use chemicals, foam, gas and O2 deprivation to stop fires from spreading, they are often used in sensitive areas such as museums or data centers.

Let’s review the different types of Fire suppression systems and their uses.

Clean Agent
Clean agent systems use inert gases such as CO2 and nitrogen or non-oily Fluorocarbons to reduce the oxygen in the air and choke out the fire. These gasses, unlike water, are electronically nonconducting and are therefore safer for electrical components. Because of this they are most often used in data centers and electronic repair centers where electrical discharge can be as damaging as smoke, fire or water damage to sensitive components.

CO2 Systems are specific clean agent systems using carbon dioxide to suffocate a fire.

Wet Chemical suppression systems are specific to commercial kitchens and put out grease and high-hat fires using cooling chemicals that interact with fats to create a foaming suppression agent.

Dry Chemical uses a large, pressurized tank of dry chemicals that are released in the event of fire and also work to choke out a fire through O2 reduction.

Fire Sprinkler Systems use water to put out fires in areas where chemical suppression would endanger the people in the space.
Some of the types of fire sprinkler systems that are frequently used are:
• Wet Pipe
• Dry Pipe
• Pre Action
• Deluge
• Foam Water Systems
• Fire Pumps
• Fire Backflow

Whatever type of fire suppression or sprinkler system you have installed, proper maintenance, adherence to NFPA code and an understanding of fire protocols are the most important elements of a total fire safety strategy. To learn more about reasons fire protection systems fail, read our article here:

technician in white hard hat looking at specs in a room of red and white pipes

It is common practice to remove the solenoid when testing and maintaining water-based fire protection systems. While the NFPA does not expressly state that this practice is dangerous, there is ample anecdotal evidence that many inspectors and maintenance workers forget to replace the solenoid after the testing.

With pre-action and deluge solenoid valves, removing the valve during testing in order to prevent accidental trip of the system is par for the course. As all building owners know, deluge systems must be fully flooded every three years, and a partial trip test performed on the off years. If the solenoid is left off after the system is tested then the entire system is, of course, impaired.

As we discussed in our article, Why Sprinkler Systems Fail, the leading cause of sprinkler system failure is human error and the removal and failure to replace a solenoid is a great example of that.

NFPA 25, The standard for Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems does not state that the solenoid cannot be removed but rather suggests a far more complex process of triggering the fire alarm panel and then resetting the system during scheduled testing and maintenance. Time constraints and the hustle of daily life often inspire shortcuts and shortcuts can increase the chance of human error. Recent changes to NFPA 13 2019 – 8.3.1.2.1 require the coil on a releasing solenoid of pre-action systems to be monitored. A fairly new product called the “CoilKeeper” can be added to a protection system and then when a solenoid coil is removed it activates a set of contacts that sends an alert to a control panel, alerting personnel that the system is being tested.

Effective January 1, 2021, NFPA 13, the Standard for Installation of Sprinkler Systems, does require that solenoids send an audible and visual signal to the panel when they are removed.

For many business owners the opaque nature of testing and inspection makes all fire protection seem shrouded in complexity and mystery. With XL Fire Protection, your testing and inspection are transparent and done according to all the latest NFPA regulations (and then some). Our teams are union installers, testing and maintenance and designers and as such adhere to the highest standards.

Urban development downtown, upwards shot of skyscrapers with a red crane on top

When it comes to commercial fire sprinkler systems, the common causes of failure include poorly installed systems, aging systems and lack of maintenance.

In residential fire sprinkler failures, improper use of fire sprinklers is more often to blame with stories of lawn sprinklers that are misused as indoor fire protection in carports or home warehousing situations, to sprinkler pipes used to support heavy cables and other pipes that collapse under the weight,.

Whether commercial or residential, the single greatest cause of fire sprinklers failing to protect life and property is human error. Ignoring activated sprinklers, turning the system off because of frequent alerts, fear of water damage that outweighs fear of fires and lack of understanding of how to operate the sprinkler system are among the reasons that systems are turned off. The National Fire Protection Association (NFPA) reports that fire sprinklers fail approximately 7% of the time—and often, those failures are a result of human error.

Properly installed sprinklers are 92% effective in the face of a real fire incident, according to the NFPA. Additionally, the rate of firefighter injuries per home fire in which sprinklers were present was 78% lower than in locations without sprinklers. In addition to loss of property, loss of life within your family or organization and the loss of life of firefighters should be enough to inspire business owners and homeowners to take sprinkler system activation more seriously.

Source NFPA


The chart above would indicate that 18% of fire situations in which sprinkler systems fail to stop the fire are caused by a manual override of the automatic sprinkler system while 57% of situations are caused by the system being shut off which, in cases of both commercial and residential fires are human error.

The most common reason that sprinklers failed to operate was that the system was shut off at some point before the fire. So, while regular maintenance of fire protection systems is essential to ensuring that the sprinkler system works in the event of fire, education and awareness within the organization is the single greatest impact outside of equipment maintenance and repair, that a business owner can take.

Taking human error off the table, the second-highest reason for fire sprinkler failure is poor or improper maintenance and inspection. Maintenance and inspection of existing systems would address 25% of sprinkler failure (referencing the above chart). A licensed inspector and maintenance team would identify and alert a business owner or homeowner to the improper use of sprinklers, the need for repair of pipes of sprinkler heads or the needed maintenance of pipes and alert systems.

As a business owner, fire safety may seem like an unnecessary hassle, yet another regulation that has to be addressed. But the protection of your property and your greatest asset, your people, is not just another box to check.

Read on to learn more about the design-build process for retrofitting buildings with the most up to date AES and fire sprinkler systems.

fire extinguishers

Renovating a historic building in the heart of a major metropolis always will cause some heartburn for the principals.

The Wilshire Grand Center and the city of Los Angeles was no exception for Brian Callahan, president of Santa Ana, California-based design-build firm XL Fire Protection.

Callahan, in partnership with Xylem Bell & Gossett were A-C Fire Pump, worked for three years to provide the 2.1-million-square-foot Wilshire Grand Center with an enhanced, sustainable fire-protection system during the hotel’s expansive $20 million makeover. Today, the 73-story glass-and-steel Wilshire Grand Center is valued at $1.35 billion and is the tallest building in the United States west of Chicago’s Willis Tower.

The Wilshire Grand Center — originally known as the Hotel Statler when it opened in 1952 — selected Callahan and XL Fire Protection because of the strong working relationship Callahan’s company has with Starfire, an Anaheim, California-based Xylem A-C Fire Pump distributor.

“Starfire worked with us to meet the requirements of the job,” Callahan states. He adds that XL was responsible for the design, calculations, testing and installation of all the Wilshire’s sprinkler systems.

Starfire’s Paul Bennett says the Wilshire Grand Center was no ordinary job for all parties involved in the design and installation.

“Because of the staging of the pumps, it took a lot of fine-tuning of the product to meet the customer’s requirements,” he says. “It was an involved process, much more than typical jobs. High-rise projects in Los Angeles are far more demanding than a warehouse project. We have to spend a lot more time to make sure the pumps properly perform.”

Los Angeles and the state of California have strict fire-safety building codes. The facility’s design was driven by NFPA 20: Standard for the Installation of Stationary Pumps for Fire Protection, according to Brian Buscher, global product manager — fire protection with Xylem.

“Because of the requirements of the city of Los Angeles for maximum pressure, we had a lot of back and forth on pump selection,” Buscher notes.

Buscher states city officials would immediately fail the facility’s acceptance test if one gauge read even one hair more than 600 psi as the pumps are churning.

“This is a hard ceiling,” he says.

Callahan, Buscher and their respective teams designed a system featuring two pumps working in series. “(Therefore), both pumps need to be spot-on the factory curve when operating in the field,” Buscher says.

He adds: “This is a tall building, so that factor alone got us close to the 300-psi limit per pump. Because it was so close, we had to hit the design point. NFPA 20 requires shutoff head to not exceed 140% of the design pressure and can’t be below 65% at 150% of the rated flow.”

In the details

Callahan says he sketched out the Wilshire Grand Center design on a napkin and impressed decision-makers with the ability to create a system that required only one fire-pump room.

“By getting the number of pumps down to six there was no need for an additional emergency generator, saving project cost,” he explains. 

After the design was ready to go the team had to make sure it would work as planned. There is a high zone with vertical turbine pumps and a low zone with A-C Fire Pump 8200 series horizontal split-case pumps that are specified in the building. It required plenty of sizing and theoretical planning on the pump curves, especially in the high zone. Los Angeles code requirements demanded an exact set of redundant fire pumps on each level, meaning six total pumps were installed.

“We had to run a lot of calculations to predict that we could meet the requirement,” Buscher says. “Then there was a lot of coordination between our Morton Grove, Illinois, plant where we make the split case pumps and the Lubbock, Texas, plant where we make our turbine pumps. We had to be sure that together we actually delivered the combined performance.”

The vertical pump and the horizontal split pump were a perfect tag team for the Wilshire Grand Center. “The vertical was a bit over psi, but the horizontal was under psi,” Buscher states. “So we met the requirements.”

Bennett adds: “One pump services the low zone, but the high-zone portion requires two pumps in series to create the 600 psi that was required.”

The only specific modification made was to adjust the standard impeller trim diameter, Buscher says.

“(We made the change) so it was not overpressurizing the system components downstream of the pump,” he notes. “We retained that information in our records in case the customer ever needs a new impeller.”

Additionally, Callahan used pressure-reducing valves to control the pressure throughout the fire-sprinkler system.

“We were able to control the static pressure the turbine pumps generated,” he says. “Even at churn, the pumps were generating 77 psi, so we needed a pressure-reducing valve on the standpipe.”

The innerworkings

The original Wilshire Grand’s HVAC system accounted for as much as 50% of the building’s commercial building energy use, thus designing a new, efficient heating and cooling system was important to meeting the LEED Gold sustainability goal.

The system specified Bell & Gossett pumps featuring a central plant with high-efficiency chillers and condensing boilers to supply chilled and hot water throughout the facility. Los Angeles-based ACCO Engineered Systems designed the HVAC system and John Boncich, the firm’s senior vice president, noted they had to design obstacles to overcome.

“A major challenge on the project was the construction had to begin prior to the completion of the design,” he says. 

The Wilshire Grand Center stands 1,100 feet high, anchored by a seven-level podium structure featuring retail, restaurants, meeting rooms, ballrooms and a swimming pool. On top of the podium is 400,000 square feet dedicated to office space.

The podium and office levels are supplied chilled and hot water by Bell & Gossett 300-psig working pressure VSX and e-1510 pumps. The thermal energy storage system is served standard working pressure VSX pumps on the podium’s second level. That thermal energy storage system charges a large water tank overnight to lower the number of chillers needed to operate the building throughout the day.

Other elements of the Wilshire Grand’s HVAC system include Bell & Gossett AHRI-400 certified plate-and-frame heat exchangers that isolate the facility’s pressure zones from each other. Also, the HVAC system includes air separators and expansion tanks that adjust pressures in the hydronic system in response to building temperature changes.

More VSX pumps are used to provide comfort to guests at the Intercontinental Los Angeles Downtown hotel, which covers floors 31-66, has nearly 900 rooms, a sky lobby on the 70th floor, and bars and restaurants on floors 69 and 71. Bell & Gossett e-90 inline pumps provide radiant floor heating and cooling in the ground-floor lobby and in the sky lobbies. 

Pomona, California-based manufacturers representative Dawson Co. supplied the HVAC system and vice president of commercial sales Manuel Masso notes how the units provided benefits beyond energy efficiency.

“Besides the versatility and robustness the VSX brings to a high-efficiency hydronic system, it’s easily serviceable and its compact design takes up less space in the pump room,” he says. “De-creasing the size of mechanical rooms means more saleable space.”

Cohesive unit

Despite all the elements of the Wilshire Grand Complex it covers only 2.8 acres and it did not offer extra space to store materials during or after construction. Products were lifted by cranes when needed.

During testing, the fire-protection team adjusted sequencing with the pump controller and was able to close the startup gap from 10-15 seconds to seven.

“In the end, everything worked as designed,” Callahan declares. “It’s not just putting in products; everything had to properly perform as a system and meet code.”

The new beacon of the Los Angeles skyline stands out for reasons beyond height and, according to Bennett, it was because of a coordinated team effort.

“Customer service is so important in our industry, especially on high-profile projects such as the Wilshire Grand Center,” he says. “Having those personal relationships with customers such as XL Fire Protection means they know we will do what needs to be done to meet the requirements of the job.”

This article was originally titled “Fire protection grand slam” in the May 2018 print edition of PM Engineer.