Fire Safety

Fire Alarm System for a Factory: Addressable vs Conventional, Device Count and Cost Drivers

Name: Secured Engineers Private Limited — Noida (Delhi NCR)
Address: Supertech, Astralis Supernova, Sector 94, Noida, Uttar Pradesh, 201301, IN
Telephone: +91 70099 85817

22 October 2026 · 5 min read · by Secured Engineers Editorial Team

Title card reading Fire Alarm System for a Factory with a floor plan, detector symbols and an alarm panel outline. — Title card. Not a photograph of a Secured Engineers site.

A factory fire alarm system costs what its device count, panel and loop architecture, cabling and interfaces add up to. Addressable systems cost more per device but locate a fire to one detector; conventional systems report by zone. Count detectors from the floor plan and ceiling heights, divide them into zones or loops, then price the panel, devices, cable, interfaces, commissioning and annual maintenance as separate lines.

Which rules decide whether a factory needs a fire alarm?

The National Building Code, Part 4 (Fire and Life Safety), covers fire detection and alarm in clause 4.9 and sets the requirement for each occupancy in Table 7. It also says the detection system shall follow accepted standards, and that alarms should be planned to operate other life-safety equipment, such as air-handling units, pressurisation, fire-door hold-opens and the monitoring of fire water tanks and pumps. Your state fire law and the fire NOC set the final requirement for your building; see our factory Fire NOC guide.

The design standard is IS 2189, the BIS code of practice for automatic fire detection and alarm systems. BIS's standards page lists the 2008 edition as withdrawn, and a 2026 fifth revision is reported, so ask the fire authority which edition it applies. The figures in this article come from the 2008 text and are examples of how detector counts are built; verify them against the edition in force.

Addressable or conventional: how do they differ?

A conventional panel monitors zones: when a detector trips, the panel shows the zone, and someone walks it to find the device. An addressable panel gives each detector, call point and module an identity on a loop, so it reports the exact device. IS 2189 still expects zoning indications on addressable systems, because a zone shows the spread of a fire at a glance.

	Conventional	Addressable
What the panel reports	The zone	The individual device, plus zone
Wiring	One cable run per zone, ending at a line resistor	A loop, wired so a single break still leaves every device working
Zone or loop limits (IS 2189:2008)	A zone should not exceed 2,000 m² of floor; search distance within a zone should not exceed 30 m	Per-loop device limits set by the maker; keep to about 90% of capacity; fault isolators every 20 to 30 devices; loop length within 3,000 m
Cost pattern	Lower panel and device cost; more home-run cable in a big plant	Higher device and panel cost; less cable and faster fault finding
Fits	Small, simple buildings and warehouses with few zones	Larger plants, multi-building sites, integration with other systems

Hybrid systems use addressable modules to connect conventional detectors where they are needed, for example in a hazardous area. A conventional system in a large plant can still cost more over its life because every fault is found on foot.

How do you count the devices?

Start with a plan showing every room, ceiling height and ceiling type. Then lay detectors out by the standard's rules and cross-check the total.

Coverage distance. Under flat ceilings, IS 2189:2008 keeps any point in the area within 7.5 m of a smoke detector, or 5.3 m of a heat detector. Beams deeper than 10% of the ceiling height form separate bays, and detectors stay clear of walls and deep obstructions.
Cross-check. After laying out spacing, check that the compartment has at least one smoke detector per 100 m², or one heat detector per 50 m².
Selection. Smoke detectors suit offices and stores. Heat detectors suit dusty, steamy or smoky processes where smoke detectors would false-alarm. High bays need beam detectors or aspirating systems, and paint, solvent and battery areas need hazardous-area rated devices.
Manual call points and sounders. Put call points at exits and along escape routes. The 2008 text sets sounder levels of 65 dB(A), or 5 dB(A) above any persistent ambient noise, whichever is greater, so noisy production floors need extra sounders or beacons.

As an arithmetic illustration, a 4,000 m² flat-ceiling production hall needs at least 40 smoke detectors or 80 heat detectors by the cross-check before you add electrical rooms, ceiling voids, stairs and offices. Real counts exceed the minimum.

What else moves the cost?

Cost driver	How it moves the number	How to specify it
Panel and loops	More loops mean larger panels, power supplies and enclosures	State loop count and spare capacity; ask for panel networking if the site has several buildings
Detector type	Smoke, heat, multi-sensor, beam and aspirating devices differ widely in unit cost	Give a type per area on the schedule
Ceiling height	High bays need beam or aspirating detection and access equipment	List heights and the access method for testing
Cable and containment	Fire-resistant cable and conduit can be a large share of a big plant	Ask for cable lengths in the BOQ and the cable type
Hazardous areas	Certified devices and barriers cost more	Mark classified zones on the plan
Interfaces	Pump status, AHU shutdown, door release, access control and BMS links add modules and testing	List each interface and who tests it
Power backup	Larger panels need larger batteries	State the required standby and alarm duration
Commissioning and handover	Programming, testing, drawings and training are real work	Make the test certificate and as-built drawings part of the scope
Maintenance	IS 2189 describes weekly user checks, quarterly tests and annual tests, with a share of detectors tested each year	Price the annual maintenance contract with the capital cost

How should you compare fire alarm quotes?

Ask every bidder to price from your device schedule, not their own. Check that the quote lists device counts by type per area, loop count with spare capacity, cable type and length, every interface, sounder coverage, the commissioning tests and documents, warranty, training and the first-year maintenance. A quote that omits interfaces or testing looks cheaper and is not. Our fire-fighting BOQ guide and RFQ template show how to structure the request. We quote no price here because the number depends on the plant.

How Secured Engineers helps

We design fire detection and alarm in-house with the rest of the fire-fighting scheme, and file the Fire NOC ourselves. MEPF and solar can sit under one contract, so alarm interfaces with HVAC, electrical and pumps are coordinated in one design. We work from Noida (Delhi NCR) and Ludhiana, across 535+ projects in 18+ states, with 89.77% repeat clients. We do not sell audits; we review a budget or design and can carry out the rectification works.

If you hold a fire alarm quote or BOQ, send it with the floor plans and we will check the counts, zoning and interfaces against the drawings. See our fire detection and alarm systems page, message us on WhatsApp, call +91 70099 85817, or ask for a free proposal.

Frequently asked

Is an addressable fire alarm system worth the extra cost in a factory?

For a large or multi-building plant, usually yes. An addressable panel shows the exact device in alarm, so responders reach the fire faster, and a loop needs less cable than many zone circuits. For a small shed with a few zones, conventional can be sufficient. Compare lifetime cost, including fault-finding time and maintenance, not only the panel price.

How many smoke detectors does a factory need?

It depends on area, ceiling height, beams and obstructions. IS 2189:2008 keeps any point within 7.5 m of a smoke detector under a flat ceiling and cross-checks at no fewer than one per 100 m² of compartment. High bays use beam or aspirating detection. Count from a plan, room by room, and confirm the edition your fire authority applies.

Does a factory fire alarm have to connect to the sprinklers and pumps?

The National Building Code says detection and alarm should be planned to operate related life-safety systems, such as air-handling shutdown, pressurisation, fire-door release and monitoring of fire water tanks and pumps. The interfaces needed for your building depend on its occupancy and fire NOC. List each interface in the tender so it is priced and tested.

Why are fire alarm quotes for the same factory so different?

Usually because the scope differs. Bidders may count different device numbers, leave out interfaces, use cheaper cable, exclude commissioning tests or omit maintenance. Ask all bidders to price from one device schedule and compare line by line. A quote materially below the others often removes scope rather than saving money.

How often must a fire alarm system be tested?

IS 2189:2008 describes a weekly test by the user, a quarterly inspection and test, and an annual inspection in which a share of detectors is checked each year so that all are tested within five years. Your fire NOC and insurer may add requirements. Include the maintenance contract and test records in the budget from the start.