Design of a fire alarm system (FAS)

Why is an incorrectly designed FAS more dangerous than its absence?

A fire alarm system developed without taking into account the current regulatory framework, real characteristics of premises and algorithms for interaction with protection systems creates a false sense of security. The detectors are installed, the wires are laid, the control device blinks green - but at the time of a real fire, the system either does not recognize the threat in a timely manner or does not generate control commands in the required sequence. The most common reasons for such situations are the choice of the type of detectors without analyzing the fire load of the room, incorrect zoning FAS control zone, the use of a fire confirmation algorithm that does not correspond to the class of the object, and the lack of the required redundancy for power and control.

AYU-Project designs fire alarm systems for residential, public, commercial and industrial buildings in strict accordance with SP 484.1311500.2020 (with Change No. 1, approved by Order EMERCOM of Russia from 27.03.2025 No. 252, effective from 01.09.2025) and current requirements Federal Law No. 123-FZ. Our design documentation and working documentation undergo internal regulatory control before transfer to the customer and are accepted by state and independent expert review, as well as by EMERCOM authorities from the first presentation.

Classification of fire alarm systems: which one to choose?

The FAS type is determined at the DD stage and directly determines the cost of installation, the possibility of integration with FPSA and the accuracy of the source localization. AYU-Project designs all types of systems, applying each according to its advantages.

Threshold (addressless) systems - the simplest architecture: detectors are combined into loops, the alarm signal identifies only the loop, not a specific detector. Justified for small facilities with a uniform functional purpose of the premises and minimal requirements for localization accuracy. When reconstructing buildings with existing addressless infrastructure, they can be used to reduce the cost of replacing the cable network.

Address systems - each detector has a unique address; The control device displays the exact location of the trigger. Significantly reduce personnel response time and provide accurate localization for FPSA. They are used on objects of medium and high complexity.

Analogue addressable systems - the most informative class: the detector transmits to the control device not just the fact of an alarm, but the current measured value of the controlled factor (smoke level, temperature, CO concentration). The device analyzes the dynamics of changes in parameters and makes a decision about a fire using customizable algorithms, rather than a rigid threshold. This ensures minimal time before an alarm is declared in a real fire and maximum protection against false alarms.

Aspiration systems (IPDA) - highly sensitive detectors that actively take air from the controlled area through a network of tubes with air intake holes and analyze it in an optical chamber. Provide detection at the earliest stage of a fire (pre-fire condition, “invisible” smoke). Indispensable in server rooms and data center, historical buildings, rooms with intensive ventilation, cold warehouses with condensation and in areas where the installation of conventional detectors is structurally difficult. From 1 March 2021 the arrangement of IPDA is carried out according to the requirements SP 484; For addressable analog IPDAs, the transmission of the current smoke level and advanced diagnostics to the fire station is standardized.

Types of fire detectors: how is the type selected for each room?

The choice of detector type is the first and main engineering task when designing an emergency fire alarm system: it is determined not by the preference of the installer, but by the nature of the fire load and environmental conditions in a particular room.

Optical smoke detectors - the most common type: they react to suspended smoke particles in the infrared spectrum. They are used in administrative, residential, commercial, warehouse and most industrial premises. Not recommended in rooms with process steam, dust or combustion products (boiler rooms, kitchens, woodworking shops) - in such conditions thermal or multi-criteria detectors are used.

Heat detectors - react to exceeding the threshold temperature (maximum) or to the rate of its growth (differential) or to both parameters (maximum-differential). They are used in areas where smoke detectors are inoperative: garages, boiler rooms, kitchens, cable shafts, technical undergrounds.

Flame detectors respond to optical radiation from an open flame in the UV or IR spectrum. They are used in high industrial premises, where the speed of smoke growth to detectors under the ceiling is insufficient, as well as in open installations in the oil and gas and chemical industries.

Multi-criteria and multi-sensor detectors - analyze several fire factors simultaneously (smoke + heat + CO + flame) with correlation logic for signal processing. Provide the best balance of sensitivity and protection against false alarms. Optimal for facilities with high reliability requirements and rooms with difficult environmental conditions.

Manual call points (IPR) - manual fire reporting buttons installed on escape routes. According to Amendment No. 1 to SP 484.1311500.2020 (clause 6.4.1) the triggering of the IPR is an independent basis for making a decision about a fire, regardless of the algorithm used in this ZKSPS.

Fire confirmation algorithms A, B, C: what has changed in SP 484 since 2025?

The fire confirmation algorithm is a regulated logic for making a decision about a fire by a control panel based on signals from detectors in a given ZKSPS. Change No. 1 to SP 484.1311500.2020 (effective from 01.09.2025) clarified and formalized three algorithms:

Algorithm A - the decision about a fire is made based on the signal from one detector in FAS control zone. It is used when using aspiration IPDA or multi-criteria detectors that independently provide high signal reliability, or in high-risk areas where confirmation delay is unacceptable.

Algorithm B - a decision is made when two detectors are triggered in one ZKSPS (temporal or spatial cross-check). The most common algorithm for analog addressable systems: provides a balance between detection speed and protection against false alarms.

Algorithm C - a decision is made when one detector is triggered, followed by confirmation through a repeated poll (re-query) within a specified time. Used for addressless loops with smoke detectors.

Change No. 1 further confirmed: for different FAS control zone of the same object it is allowed to use different algorithms; triggering of IPR always generates a “Fire” signal, regardless of the algorithm used in FAS control zone; different rooms of the same FAS control zone can be served by different algorithms - which significantly expands design flexibility.

Zoning FAS control zone and fire protection zone: what is the difference and how does it affect the project?

Correct zoning is the basis of the FAS project SP 484.1311500.2020 (ed. with Amendment No. 1). ZKSPS (fire alarm system control zone) and ZPZ (fire protection zone) are different concepts with different functions.

FAS control zone - a zone for which the ATP generates a separate “Fire” signal: one or more premises, united according to the principle of the same type of response. The size of the ZKSPS is standardized: for addressable systems - no more than one floor or other restrictions on SP 484. The more accurately FAS control zone corresponds to a real planning unit, the more accurate the fire localization.

fire protection zone - a part of a facility in which a similar fire protection system operates independently of other parts. The size and composition of the fire protection zone determines which actuators of the emergency protection zone are controlled simultaneously when a “Fire” signal is received from this fire protection zone. Change No. 1 to SP 484 introduced the independence requirement of fire protection zone: a single fault in one fire protection zone should not disrupt the functionality of other zones.

Incorrect zoning is one of the most common reasons for the expert’s comments: premises with different fire loads are combined into one ZKSPS, or the ZKSPS does not correspond to the actual engineering systems of the facility.

Power supply redundancy FAS: regulatory requirements

Power redundancy FAS is a regulatory requirement, not an additional option: SP 484.1311500.2020 establishes that the system must remain operational in the event of a failure of the main power source for at least 24 hours in standby mode and one hour in alarm mode (for most facilities). Calculation of the capacity of backup batteries is performed based on the power consumption of all system devices in both modes and is a mandatory attachment to the DD.

For particularly critical facilities (facilities with large numbers of people, buildings with a height of more than 28 m), power is provided from two independent power supply inputs with automatic reserve input (ATS) and additional battery backup. The power supply diagram FAS is developed as part of WD, indicating the ratings of protective circuit breakers, cable sections and capacities battery bank.

Integration of SPS with ASPS, SOUE and building engineering systems

Modern FAS is not an independent system, but a source of the primary signal for the entire fire protection complex. Integration is designed at the level of control algorithms: the “Fire”, “Start”, “Extinguishing” and “Fault” signals, generated by FAS in a specific FAS control zone, enter FPSA and initiate a given chain of reactions.

WD includes an interaction matrix: a table that determines which signal from which FAS control zone triggers which control commands for each actuator. Integrated systems and devices:

• SOUE - launching voice notification for the corresponding broadcast zones;
• Smoke ventilation - opening smoke exhaust valves and closing fire suppression valves of the required zones;
• AUP - launching the fire extinguishing installation in the protected area after confirmation of the fire;
• Elevators - transfer to the “Fire danger” mode: the elevators return to the main landing floor and are blocked;
• Air conditioning and ventilation systems - shutdown of general ventilation in the fire zone;
• ACS - unlocking emergency exits when an alarm is declared;
• BMS (building dispatch systems) - transfer of the status of all ATP devices to the central control station.

What is included in design documentation and working documentation on FAS?

Documentation is developed in accordance with Government Decree of the Russian Federation No. 87 dated 16.02.2008 No. 87 (as amended on 21.10.2025) “On the composition of sections of project documentation and requirements for their content” and SP 484.1311500.2020 (with Change No. 1).

Design documentation stage includes:

• an explanatory note describing the adopted system, justification for the type FAS and types of detectors;
• ZKSPS and ZPZ zoning plan;
• description of fire confirmation algorithms for each ZKSPS;
• block diagram of the system with designation of the control device, zones and actuators;
• description of algorithms for interaction of FAS with FPSA, EVAC and engineering systems;
• power supply diagram with calculation of the capacity of backup power supplies.

Working Documentation Stage (WD) contains:

• plans for the placement of detectors, IPR, control devices and sirens with reference to building axes;
• circuit diagram FAS with the designation of all loops, address lines and control lines;
• equipment layout diagram in the cabinet or on the control device rack;
• cable log and cable routing diagrams;
• calculation of the number of detectors and the control area of each;
• calculation of autonomous operation of power supplies;
• interaction matrix FAS - FPSA - EVAC;
• power supply diagram FAS with parameters battery bank;
• specifications of equipment and materials;
• statement of quantities.

Regulatory design basis FAS

• SP 484.1311500.2020 with Amendment No. 1 (EMERCOM of Russia Order dated 27.03.2025 No. 252, valid from 01.09.2025) - basic set of rules: design standards FAS and FPSA, zoning, A/B/C algorithms, redundancy requirements;
• SP 486.1311500.2020 - list of objects to be equipped with FAS;
• Federal Law No. 123-FZ “Technical Regulations on Fire Safety Requirements” - requirements for fire protection systems;
• GOST R 53325-2012 (ed. 2014) - technical means of fire automatics: general requirements for detectors and control devices;
• GOST R 34.13130.2022 (SP 7.13130.2013) - regarding the interaction of FAS with smoke ventilation;
• GOST R 21.1101-2020 - requirements for working documentation (WD) formatting;
• Government Decree of the Russian Federation No. 87 dated 16.02.2008 No. 87 (as amended on 21.10.2025) “On the composition of sections of project documentation and requirements for their content.”

Pricing and how to order

The cost of developing design documentation and working documentation on the SPS depends on the area of the facility, its functional purpose, the number of ZKSPS, the type of system (addressless, addressable, addressable analogue) and the composition of the integrated subsystems. When ordering SPS, SOUE, ASPS and AUP simultaneously under a single contract, a cost reduction is provided. Approximate calculation - through the online calculator on the website.

To receive an accurate commercial proposal, leave a request: indicate the type and area of the property, number of floors and available initial data. The initial consultation is free, and we work remotely across Russia.