The ISU File for Smoke Extraction Systems: What the Inspector Checks and What Gets Your Project Rejected

You have finished the smoke extraction design. You have selected the fans, calculated the airflows, drawn the schema. You submit the file to ISU.

And it comes back: rejected.

Not because the dimensioning is wrong. Not because the fans are unsuitable. But because a certificate is missing, a declaration of performance is in the wrong format, or the normative reference is the old one.

This happens frequently since P118-1:2025 came into force (Order no. 267/2025, published in the Official Gazette, in force from 9 May 2025). ISU inspectors now apply stricter and more clearly defined criteria. Any missing or non-compliant document means restarting the procedure — with delays of 30–90 days and additional costs for the client.

This article gives you the exact list of required documents, what the inspector checks for each one, and where to get them for fans available at ventilation.ro.

Which Fan Classification Does P118-1:2025 Require — F400, F300 or F200?

This is the first question you must answer correctly before selecting the product and before submitting the documentation.

Art. 8.4.2 (1) of P118-1:2025 states explicitly:

"Fans for smoke evacuation in case of fire by mechanical ventilation shall be fire-resistant class F400/120."

F400/120 is therefore the general rule — not F300. Two exceptions are provided in the same article:

Art. 8.4.2 (2): In buildings equipped with automatic water-based fire suppression systems (sprinklers), fans class F200/120 may be used instead.

F300/120 applies to fans installed in the risk zone — meaning fans located inside the protected space, in direct contact with smoke (for example, Jet Fans in underground car parks, in accordance with the normative).

Quick reference table for classification selection:

Always verify with the fire safety designer which classification applies to the specific configuration of your project.

Why the ISU File Has Become Stricter After P118-1:2025

P118-1:2025 completely replaces normative P118-99 — a document over 25 years old. The new regulation requires that documentation must be complete at the first submission, and smoke extraction equipment must be explicitly identified with conformity documents, not mentioned generically.

Two concrete changes directly affect smoke extraction fans:

1. The reference to EN 12101-3:2015 is mandatory, not optional. It is no longer sufficient to write "fire-resistant fan 400°C/2h". The document must specify conformity with EN 12101-3:2015 and include the certificate number from the notified body.

2. The Declaration of Performance (DoP) must be in CPR format (Construction Products Regulation — EU Regulation 305/2011), not simply a technical datasheet. A catalogue or product brochure does not replace a DoP.

Complete Document List — What Goes in the File

Document 1: EN 12101-3:2015 Certificate Issued by a Notified Body

What it is: Proof that the fan has been physically tested at the certification temperature (F200/120, F300/120 or F400/120) by an independent European laboratory, accredited and notified by the European Commission.

What the inspector checks:

• The certificate number 
• That the classification in the certificate matches the classification required by the project (F400, F300 or F200 — per the table above)
• That the certification duration is 120 minutes — not 60 minutes
• That the notified body is recognised (APPLUS has code 0370 — visible in the certificate number)
• That the certificate has not expired

Common mistake: A technical datasheet or catalogue is submitted instead of the actual certificate. The inspector rejects it — a datasheet has no legal standing in place of the certificate.

Where to get it: EN 12101-3:2015 certificates for Casals products are available on each product page under "Technical Documents". Download directly or request them at the time of ordering.

Document 2: Declaration of Performance (DoP)

What it is: The document by which the manufacturer declares that the product meets the essential characteristics required by the harmonised standard (EN 12101-3) and the Construction Products Regulation (CPR 305/2011). The DoP underpins the CE marking of the product.

What the inspector checks:

• That the DoP exists and has an identification number
• That the product reference in the DoP corresponds exactly to the model specified in the project — not "axial fan 63" but exactly "Casals HBF 63 T4 0.75kW (A2:9) F300, cert. 0370-CPR-2402"
• That the essential fire characteristics are declared: operating temperature, duration, classification type
• That the DoP references the same notified body that issued the certificate

Common mistake: The DoP is old, referencing EN 12101-3:2002 (the superseded standard) instead of EN 12101-3:2015. The product may be technically identical, but the document is no longer valid under P118-1:2025, which requires conformity with the 2015 version of the standard.

Document 3: Technical Datasheet with Performance Curves

What it is: The document demonstrating that the selected fan delivers the airflow and pressure required by the smoke extraction calculation — at the specified operating temperature.

What the inspector checks:

• That the airflow in the datasheet covers the airflow calculated in the project
• That the available static pressure covers the system resistance
• That performance is declared at the certification temperature — not at 20°C. An F400 fan delivering 20,000 m³/h at 20°C delivers less at 400°C, because air density decreases with temperature. The datasheet must clarify this, or the calculation must include the correction factor.

Common mistake: Performance data at 20°C are used without the correction factor for emergency temperature. The airflow calculation is incorrect, and the system does not achieve the required extraction in a real fire.

Document 4: Installation Schema with All Equipment Identified

What it is: The installation plan showing the positioning of all components — fans, ductwork, fire dampers, smoke extraction outlets, and automatic and manual controls.

What the inspector checks:

• That each smoke extraction fan is identified with its exact model — not "F400 fan" but for example "Casals HBF 63 T4 F300, cert. 0370-CPR-2402"
• That smoke extraction ductwork is from materials class A1 or A2-s2,d0, with fire integrity rating E600/30 — a specific P118-1:2025 requirement
• That there is electrical supply from two independent sources (Art. 8.4.3 P118-1:2025) — generator + public grid, or UPS + public grid. A single backup source is not sufficient
• That there is mandatory dual control — automatic (from the fire control panel) and manual centralised control from the UCMS (Unitatea de Comandă Manuală centralizată de Securitate / centralised manual security control unit). This is a new requirement introduced explicitly by P118-1:2025, systematically checked by inspectors
• That activation of the smoke extraction system automatically interrupts normal ventilation and air conditioning (Art. 8.1.5 P118-1:2025)

Common mistake: UCMS manual centralised control is missing from the schema. Electrical supply provides only one backup source, not two independent sources.

Document 5: Smoke Extraction Airflow Calculations per Zone

What it is: The calculation demonstrating that the total airflow of the smoke extraction fans meets the normative requirement for the building type.

What the inspector checks:

• The calculation methodology (analytical or CFD)
• That the correction factor for air density at operating temperature has been applied
• For car parks with more than two levels or complex geometry (atriums, shopping centres): CFD study in accordance with SR CEN/TR 12101-5 — P118-1:2025 explicitly recommends this. ISU may request CFD validation even when the analytical calculation appears sufficient

Common mistake: Simple analytical calculation for a car park with columns or asymmetric geometry, without CFD validation. Without simulation, there is no proof that smoke evacuation actually occurs in a real fire.

Document 6: Commissioning Report

This applies to the authorisation phase (after construction), not the design approval file. However, many designers confuse the two stages:

• ISU design approval (aviz) = obtained on the basis of the project, before construction
• ISU operating authorisation (autorizație) = obtained after construction, on the basis of the commissioning report

The commissioning report must attest that the installed fans correspond to those in the approved project and that the system has been tested and operates in accordance with the designed parameters.

The 5 Main Reasons for Rejection — and How to Avoid Them

Reason 1: F300 fan instead of F400 (or incorrect classification) → Check Art. 8.4.2 of P118-1:2025 for the specific configuration. General rule: F400/120. Exception with sprinklers: F200/120. F300/120 for fans in the risk zone. Do not assume — verify with the fire safety designer.

Reason 2: EN 12101-3 certificate missing or referencing the old standard (2002) → Request the certificate from the supplier before writing the specification. If the supplier cannot provide an EN 12101-3:2015 certificate, do not buy from them. All products in the fire smoke extraction category at ventilation.ro have their certificates available immediately.

Reason 3: Only one backup electrical source instead of two independent sources → Art. 8.4.3 of P118-1:2025 requires two independent sources. Include both the public grid and a generator (or UPS) in the schema, with automatic switchover.

Reason 4: UCMS missing from the schema → Centralised manual control from the building's fire dispatch centre is mandatory under P118-1:2025. Verify that it appears explicitly in the installation schema — ISU checks this systematically.

Reason 5: Performance data without temperature correction factor → Smoke extraction fan performance must be corrected for air density at the certification temperature. The Casals datasheet includes performance curves at the certification temperature — use those values, not the figures at 20°C.

What You Receive from ventilation.ro at the Time of Order

All fans for fire smoke extraction are supplied with complete documentation, ready for the ISU file:

On request, we also supply:

• CE declaration of conformity signed for a specific batch
• Technical datasheet with performance data at the certification temperature (F300°C or F400°C)
• Support for completing the specification document in accordance with P118-1:2025

Permanent stock:

• F300 axial fans — HBF 50–100 T4 series
• F400 axial fans — HBF/HMF 50–125 T4 series
• F400 roof fans — DHUMAT, RDM full range
• F300/F400 centrifugal Jet Fans for car parks — SYBILO, JFCB full range

Specification Template — Correct Wording for ISU Submissions

Copy and adapt this wording directly into your specification document:

Fan [axial / roof / Jet Fan] for fire smoke extraction, type Casals [full model name], fire-resistant class [F400/120 or F300/120 or F200/120 — per Art. 8.4.2 P118-1:2025], in accordance with SR EN 12101-3:2015, certified by notified body APPLUS (code 0370), certificate no. [0370-CPR-XXXX]. Asynchronous motor [IE3], protection class IP55, insulation class H. Maximum airflow: [X] m³/h. Connection diameter: Ø[X] mm. Electrical supply: from two independent sources, per Art. 8.4.3 P118-1:2025. Manufacturer: Casals Ventilación S.A.U., Spain. Authorised distributor in Romania: Ioannina Impex SRL — ventilation.ro.

If you would like the full editable Word template with standard specifications for the complete Casals F300, F400 and F200 range, send us an email with the subject line "Request P118 standard specification" — you will receive it free of charge the same day.

Further Reading:

• Normative P118-1:2025 — what changed for designers
• Jet Fans for underground car parks — complete guide
• F400 vs. 250°C continuous — the difference nobody explained

📞 +40 722 667 239 — We confirm the correct classification (F400/F300/F200) and certificate availability for your model on the same day.

✉ ioannina@ioannina.ro — Send the model reference and project configuration

🌐 ventilation.ro/category/evacuarea-fumului-in-caz-de-incendiu — Download technical datasheets and certificates directly from the product page.

Note: This article summarises requirements from P118-1:2025 (Art. 8.4.2, 8.4.3) and EN 12101-3:2015 for information purposes only. It does not replace consultation with an ISU-certified fire safety specialist. The smoke extraction project must be prepared and signed by a qualified designer, who verifies the applicability of each provision to the specific building configuration.

ventilation.ro — Ioannina Impex SRL | Authorised Casals importer in Romania All products supplied with EN 12101-3:2015 certificate, DoP and CE declaration of conformity.