Each type of construction product has its own way of expressing fire performance. Through this series, we explain how to read and interpret classification codes according to the relevant European standards.
Part 2 – Fire Resistance Classification of Fire Dampers
Applicable standards
- Testing: EN 1366-2:2015
- Classification: EN 13501-3:2025
- Extended application of test results: EN 15882-2:2022
| Designation | Meaning | Note |
|---|---|---|
| E | Integrity | |
| EI | Integrity and Insulation | |
| ttt | Classification period | 15, 20, 30, 45, 60, 90, 120, 180, 240 minutes |
| ve | Vertical orientation of supporting construction | Into horizontal duct |
| ho | Horizontal orientation of supporting construction | Into vertical duct |
| S | Smoke leakage | Valid for duct A only |
| without designation | Pressure on the unexposed side in the connecting duct is -300 Pa during the test | If a higher negative pressure is applied during the test, this shall be stated in the conditions of use |
How to read the classification of fire dampers
The fire resistance classification of fire dampers according to EN 13501-3 defines how long the damper maintains its integrity (E) and insulation (I) during a fire exposure. The classification also specifies the orientation of the supporting construction (ve/ho) and—where relevant—the smoke leakage criterion (S). All these elements of the classification code determine the use of the product in construction works.
Indication of the direction of fire exposure (e.g. i↔o) was used in the past as part of the classification code, but it has since been withdrawn and now each fire damper must be tested from both sides.
Example
EI 120 (ho) S
This represents the classification of a damper for horizontal supporting construction, tested from both sides, fulfilling integrity and insulation criterion as well as smoke leakage for 120 minutes.
