Photo courtesy of RentFirePumps.com
Renovating a building that already has a fire sprinkler system comes with challenges that are easy to underestimate. When the permanent fire pump is taken out of service, the building loses its fire protection coverage, disrupting building operations and business. What many project teams don’t realize is that a temporary fire pump can be rented and tied into the existing system, keeping the building protected and occupied, and allowing business to continue while the permanent pump is replaced or the system is reworked. Here’s when a temporary pump makes sense, how it works, what to consider, and why a fire protection engineer belongs in the conversation early.
Why Temporary Fire Pumps Are Useful
A renovation can take the permanent fire pump offline for any number of reasons: it’s being replaced or upgraded, its electrical service is being reworked, or the surrounding structure is under construction. Whatever the cause, the moment it’s out of service, the building has no fire protection, and that’s where a temporary pump earns its place. Building owners are generally the biggest advocates for temporary fire pumps because they keep the system functional so the building can maintain occupancy and resume business while the work gets done.
Downtime is the biggest consideration during sprinkler system renovation. Replacing a fire pump or installing new pipe is not a quick job; a contractor may have the permanent pump out of service for weeks or even months. For that entire period, the building has no active fire suppression, and in most cases, the authority having jurisdiction (AHJ) won’t allow it to remain occupied and function as usual. A temporary pump allows work that may have required weeks of system downtime to be reduced to a couple of hours to tie in the temporary pump and switch the system over.
That downtime is expensive in more ways than one. Any time a water-based fire protection system is taken out of service, the impairment procedures of NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems (Chapter 15 – Impairment, 2020 edition) come into effect: an impairment coordinator must be designated, the system tagged, and the fire department, insurance carrier, alarm company, and other AHJs notified. When the system is out of service for more than 10 hours in a 24-hour period, the impairment coordinator must arrange one or more of the following precautions: evacuation of the affected area, an approved fire watch, establishment of a temporary water supply, or a program to eliminate ignition sources and limit available fuel.
For a pump replacement typically lasting weeks, most of these options are disruptive at best. Evacuation halts business entirely, and a fire watch adds cost without restoring protection. A temporary fire pump provides an ideal solution as it allows the system to remain functional and unimpaired, except for the isolated work area itself. Renting one is often far cheaper than the business delays an owner would otherwise absorb. In complex facilities like hospitals, industrial complexes, and airports, curtailing operations is not only costly but also halts critical services that the community depends on. Underlying all of this is basic life safety. If a fire breaks out mid-renovation, occupants, tradesmen, and first responders will all be depending on the suppression and standpipe system, at the very moment hot work, open construction, and accumulated debris make fire most likely.
How Temporary Fire Pumps Work
Temporary fire pumps can be rented, rather than purchased, which makes them straightforward to acquire on a project timeline and considerably cheaper; additionally, rental companies specialize in this service and can help with planning and provide support through design and construction.
A temporary fire pump is typically delivered in a trailer or on a skid, positioned near the system it serves, and tied into the existing piping, often through the fire department connection. It needs a reliable water supply on the suction side and an electrical connection to power its auxiliary devices. Diesel units are the most common, since fuel can be stored with the pump, which doesn’t require high-powered electrical service. Modern rental units come well-equipped, with fire alarm system integration, cellular communications, lighting, and ventilation, and carry many of the same requirements expected by NFPA 20 on permanent pump installations such as, monitoring for water flow, trouble, valve tamper, low fuel, and power issues, and communicates those alerts to the building’s fire alarm panel, so the facility staff are notified and can inspect the issue, or the fire department can be dispatched in the event of a fire.
The pump must be sized to match the system demand, the same flow and pressure the permanent pump was selected to deliver; however, consideration must be made to account for the changes in piping size and type, elevation, and any other differences that may have added or subtracted elevation or friction pressure loss compared to the original pump. Devices such as pressure-reducing and relief valves that may have been installed on the original system must be accounted for in the temporary system installation to avoid overpressure. The temporary pump system is then connected to the existing piping network, its on/off pressure levels are set, then the system is tested and brought online. Once operational, building activities can carry on as usual. The permanent pump is then turned off, and the part of the system needing work can be drained down. Crews can then take their time to do the job properly, rather than rushing under the pressure of a building owner who needs their system back up and running before they can resume business.
Considerations for Temporary Fire Pumps
Bringing in a temporary fire pump can be more involved than selecting a unit off the shelf. The requirements are anchored in code: the 2022 edition of NFPA 241, Standard for Safeguarding Construction, Alteration, and Demolition Operations (section 4.3.3.3), sets out the essentials: adequate water supply, adequate electrical service, and adherence to a fire prevention program that the AHJ will typically require. Within that framework, several factors need to be met:
- Correct sizing. The pump must meet the system’s original hydraulic demand; this means reviewing the basis of design, not guessing from the existing pump’s nameplate.
- Connection and sequencing. The tie-in must be strategic, and the construction work staged optimally so sections of the building are never left unprotected longer than is absolutely necessary.
- AHJ approval. Most jurisdictions require sign-off before a permanent pump is taken offline, as detailed in a Fire Prevention Program outline in NFPA 241.
- Weather and security. An outdoor unit in a cold climate needs freeze protection and security to stay operational.
- A clear interim period. The project should be clearly laid out in a phased plan so everyone, especially the fire department, is aware of any system interruptions or gaps in suppression coverage.
Each carries code and life-safety implications, and getting any one wrong can leave a building protected on paper but not in reality.
Why You Should Hire a Licensed Fire Protection Engineer
A temporary fire pump is a useful tool during suppression system renovation and modification. The temporary system demands hydraulic calculations, sizing, connection details, an interim protection plan, and AHJ coordination that is strategically planned out and provides comprehensive protection meeting the same level of safety as the original design.
A licensed fire protection engineer will verify the system demand and specify a pump that meets those requirements. They will also ensure code-compliant tie-in to the existing system, and prepare the documentation for the AHJ so they will be confident the system will meet their expectations, and will allow the building to remain occupied and carry on business as usual. An independent fire protection engineer works for your project independently, not for a vendor or contractor, and as a result, the project design is driven purely by the life safety of the building occupants and the needs of the building owner. If your project involves taking a fire pump offline, the first step is hiring a fire protection engineer who can keep the building safe, compliant, and operational from the first day of work to the last with minimal interruption.
Vedder Engineering Ltd. provides independent fire protection engineering consulting to architects, developers, and project teams across British Columbia. If your renovation involves a fire pump or any change to an existing sprinkler system, get in touch.