Life safety systems and fire alarm verification

The fire alarm for the East Wing was the most nerve-racking system on the project, because it was not really the East Wing's system. It was a new node on the hospital's campus fire alarm network, which also served the Main Building's emergency department, inpatient units and operating rooms. Any change to the network's programming could affect how the whole hospital responded to a fire. When the fire alarm subcontractor, Sentinel Alarm & Controls, connected the first new panel in phase 1, a programming error made every smoke detector in the East Wing report to the switchboard as 'Main Building level 4'. The error was caught during testing, before the panel was put into service, but it showed why life safety systems in occupied buildings are tested more thoroughly than anything else on a project.

Life safety systems protect people when something goes wrong: they detect fire, warn occupants, control smoke, guide people out and suppress fire. In a hospital, where many occupants cannot leave on their own and the strategy is often to defend patients in place behind fire separations rather than evacuate them, those systems must work together perfectly. This lesson covers how fire alarm and related systems are verified and tested, how fire protection is kept in service during renovation, and how fire separations are checked before they are closed in.

The systems involved

Verification of fire alarm systems

In the United States, NFPA 72, the National Fire Alarm and Signaling Code, sets requirements for installation, acceptance testing and periodic inspection, testing and maintenance of fire alarm systems; its current edition is 2025, though jurisdictions adopt editions at different times. Acceptance testing of a new or modified system tests every device and function: each detector, pull station, notification appliance, supervisory device, annunciator and output. The results are recorded on a record of completion and inspection and testing forms, which the authority having jurisdiction expects to see before occupancy. When an existing system is modified, the parts affected by the change are tested, and for a networked system that can extend well beyond the new devices.

Verification is meant to be complete, not sampled. Every device is tested in place by actually operating it: smoke detectors with test smoke or a heat source, heat detectors with heat, pull stations by pulling them, waterflow switches by flowing water, signals by listening and measuring sound levels. The technician checks that the panel receives the correct signal, displays the correct location and triggers the correct outputs. On Ashgrove, that meant 612 devices in the East Wing and every programmed output linked to them, plus a check of the network interface and the Main Building panel programming affected by the new node.

Planning verification in an occupied hospital

Testing a fire alarm system makes noise and sends signals. In an occupied hospital, unannounced alarms frighten patients, disrupt care and, if signals reach the fire department, send trucks. Verification on Ashgrove was planned like a series of shutdowns: Sentinel's technicians worked at night in areas not yet occupied, the switchboard and fire department monitoring were put on test for defined zones only, signals in occupied areas were silenced or reduced where the authority allowed, and Helen's fire safety officer was present for every session.

# Nights needed for fire alarm verification
import math
groups = [('Empty areas', 380, 45), ('Next to occupied areas', 232, 25)]
window, setup = 6.0, 1.0            # hours per night, hours lost to set-up and restore
hours = 0
for name, devices, rate in groups:
    h = devices / rate
    hours += h
    print(f'{name:24s} {devices:4d} devices at {rate}/h = {h:4.1f} h')
nights = math.ceil(hours / (window - setup))
print(f'Total {hours:.1f} h -> {nights} nights for one team, {math.ceil(hours / (2 * (window - setup)))} for two')

Empty areas               380 devices at 45/h =  8.4 h
Next to occupied areas    232 devices at 25/h =  9.3 h
Total 17.7 h -> 4 nights for one team, 2 for two

Simone decided to use two teams for the phase 4 verification, finishing in two nights, because the clinic opening date was fixed and every night of testing near occupied areas carried a risk of disturbing patients.

Integrated testing of life safety systems

A fire alarm can pass acceptance testing and the building can still fail when a real fire happens, if the fire alarm's outputs do not produce the right responses in other systems. NFPA 4, the Standard for Integrated Fire Protection and Life Safety System Testing, sets out how to plan and carry out integrated testing, with an integrated testing agent, a written test plan and documented results, and NFPA has also published a standard on commissioning fire protection systems. On Ashgrove, Kwame Asante acted as the integrated testing agent, working with Sentinel, the mechanical and controls subcontractors, the elevator contractor and Helen's staff.

The integrated test found three problems that no single trade's test would have found: a smoke damper wired to the wrong relay, so it closed when the level 3 detector operated instead of level 2; card readers on one exit route that stayed locked because the access control contractor had expected a dry contact the fire alarm did not provide; and an elevator recall that worked on normal power but not on emergency power. Each was fixed and retested before the dialysis unit opened.

Keeping protection in service during renovation

While systems are being replaced, the building still needs protection. When part of a fire alarm or sprinkler system is taken out of service, the system is impaired, and fire codes and the owner's insurer require the impairment to be managed: the owner and fire department are told, the area is patrolled by a fire watch, hot work in the area is stopped or tightly controlled, and the system is restored as quickly as possible. Hospitals often add measures from their own policies, such as extra fire drills, extra fire extinguishers and stricter housekeeping, while protection or exits are compromised.

Ashgrove's procedure used an impairment permit: before any device or sprinkler valve was taken out of service, Sentinel or the sprinkler contractor completed a permit with the hospital's fire safety officer, stating the area, the reason, the start and end times and the fire watch arrangements, and the hospital assessed whether interim life safety measures were needed under its accreditation requirements. The permit was posted at the fire alarm panel, the monitoring company was told, and the permit was closed only when the system was restored and tested.

Sprinklers, standpipes and water tests

New sprinkler and standpipe piping is hydrostatically tested before it is concealed. The sprinkler installation standard used in both countries, NFPA 13, commonly requires new systems to be tested at 200 psi or at 50 psi above the maximum working pressure, whichever is higher, for two hours without loss. Flushing removes debris from underground and feed mains before the sprinklers are connected. Waterflow switches, tamper switches on control valves and the fire department connection are tested, and the installer completes a material and test certificate. Because the East Wing's sprinklers were fed from the campus fire main, the main drain test also confirmed that the existing water supply could meet the new system's demand.

Fire separations and firestopping

Renovation punches holes. Every new pipe, duct, cable tray and conduit that passes through a fire-rated wall or floor creates an opening that must be sealed with a tested firestop system, and existing separations damaged by demolition must be repaired. In a hospital, where patients are protected in place behind those separations, a missed penetration can let smoke into a patient area during a fire.

In the United States, firestop systems are tested to ASTM E814 or UL 1479, and each penetration must use a listed system that matches the type of item, the size of the opening and the rating of the assembly. On Ashgrove, every penetration was labeled with a number, the system used and the installer's name; the firestop installer photographed each one before the ceiling was closed; and an independent inspector reviewed a sample using the ASTM inspection standards for penetrations and joints. The hospital required the same labeling so that its own maintenance staff could track penetrations made after handover.

The inspection found 31 problems among the first 400 penetrations checked: mostly cables added after sealing, sealant applied too thinly and two ducts with no fire dampers where the drawings required them. Because the ceilings were still open, the fixes took a few days. Finding them after the ceilings were closed would have meant opening finished work in an occupied clinic.

Emergency lighting and exit signs

Emergency lighting is easy to forget because it only matters in the dark. Each new fixture on Ashgrove was tested by switching off the normal supply to its circuit and confirming that it lit at the required level along exit routes and stayed lit for the duration required by code. Self-contained battery units were tested for their full rated time; fixtures on the generator circuits were tested during the emergency power transfer test described in lesson 8. Exit signs were checked for visibility from every point along the route, including the temporary routes used during each phase. A light meter walk at night, with normal lighting off, found two stretches of corridor below the required illumination where a fixture had been placed behind a new ceiling bulkhead. Both were moved before the area opened.

Inspections and occupancy

Before people can use renovated space, the authorities must be satisfied that it is safe. On Ashgrove, before each phase handover, the building official reviewed the fire alarm verification report, the sprinkler test certificate, the integrated test results, the firestopping report and the emergency lighting tests, inspected the space with the fire prevention officer and then allowed occupancy of that area. Harborline kept a life safety turnover binder for each phase with every certificate in one place, because a missing document on the morning of an inspection could delay the opening of a clinic patients were waiting for.