Smoke control

Calculation to UNE 23585:2017 (trial version)

Trial application. Check results against known designs and share your feedback with the Eurisko team.

No project data: it will be requested when generating the PDF. Missing: Project, Client, Location, Engineer.

Ambient conditions: 20 °C · 101,325 Pa

1. Design objectives (4.1)

Choose one or several objectives (chapter 1 and 4.1 a). They condition the minimum height, the layer temperature limit, the design criterion, the atrium data and the requirements list; they can be changed at any time and the remaining options adjust.

Protection of the means of escape (life safety)Clear height above the escape routes per table 2 and a layer at 200 °C at most (1.1.1, 6.2.2 and 6.6.2.2). Gas temperature controlAllows designing to a maximum layer temperature to protect the structure, facades or glazing (1.1.2 and 6.6.2.3). Assistance to fire-fighting operationsSmoke-free layer for the fire-fighters. The standard sets no specific parameters: they are agreed with the competent authority and the fire service (1.1.3 and annex J). Property protectionLayer above the vulnerable goods or mean temperature limited to 550 °C; either design criterion is acceptable (1.1.4, 6.5.1 and 6.6.2.2). Depressurisation (6.11, annex I)Prevents smoke passing into the spaces adjacent to the atrium through gaps and small openings. It combines with the other objectives (hybrid designs of annex I) and enables the atrium data of section 8; it does not protect large openings or escape routes open to the atrium above the layer.

2. Geometry

Reservoir or zone nameIdentifies this calculation in the results, the PDF and the multi-reservoir project. Ceiling height (m) Building use (Table 2)Minimum clear height above the escape routes: 2.5 m for public assembly, industrial and other uses; in car parks, the lesser of 2.5 m and 0.8·H (table 2). 0.5 m is added if the layer is less than 50 °C above ambient (6.2.2 f). Smoke reservoir area (m²)Required with a mechanical system and sprinklers: it weights the cooling of the layer (E.1). Maximum per reservoir: 2,600 m² (6.6.2.6). Fire location

The fire is below a mezzanine or gallery of the same space (6.6.2.7) Small compartmentUnder A.1 of UNE 23585:2017, its largest dimension is at most five times the design fire diameter and air can enter from only one direction.

Optional geometric checks (6.6.2.6, 6.6.2.8, 6.6.2.17 and E.2)

Rectangular reservoir: length (m) Rectangular reservoir: width (m)Optional. Length and width fill the area, the longest dimension and the width perpendicular to the flow (correct it if the flow does not follow the long side). Maximum reservoir length (m)Optional. Longest dimension of the reservoir; enables the 60 m limit to be checked (6.6.2.8). Reservoir width perpendicular to the flow (m)Optional. Enables the minimum layer depth for unidirectional flow below the ceiling to be checked (E.2).Maximum distance to an extraction point (m)Optional. Greatest distance from any point of the reservoir to the nearest vent or intake; with the reservoir width it allows the three-widths limit to be checked (6.6.2.17).

3. Sprinklers Sprinklers presentSprinkler type (7.1.2)In property-protection designs it sets the activation required of the smoke control system (7.1.2 b): automatic by water flow with manual control, or manual only with CMSA or ESFR; with life safety the activation is by detection (7.1.2 a). ESFR sprinklers are always fast response.Sprinkler responseSets the table 1.1 fire for retail < 1,000 m² and the table 3 opening heat flow; the fire models are shown with the response already applied. If unknown, normal response is assumed (more conservative). For offices and hotel bedrooms table 1.1 only distinguishes the normal-response case.

Activation temperature (°C) Design operating area (m²)

4. Design fire Fire modelDisabled options show the reason: building use (section 2) or sprinklers (section 3). Racks (table 1.4) also in retail premises (6.1.2 e). Storage present

Fire area (m²) Fire perimeter (m) Lower HRRPUA (kW/m²) Upper HRRPUA (kW/m²)

Heat release: 20.25 m² × 250 / 625 kW/m² = 5.06 / 12.66 MW

5. Clear height design criterion

Recommended minimum height: 2.5 m (initial criterion for use · Table 2).

Specify a height freely, overriding the minimum for use or storage

Mandatory range: 1.35–12.15 m (1/10–9/10 of ceiling height). Always checked, including when specifying a height freely.

Design criterionThe temperature criterion is offered with the gas temperature control or property protection objectives (6.2). Enable them in section 1 if you need it.Smoke-free height (m)Height from the floor to the base of the smoke layer.

6. Ventilation System

Hydraulic diameter of the extraction point (m)For plug-holing (E.9 / E.10); for rectangular points 2·a·b/(a+b). Rectangular point: width × length (m)Optional: computes the hydraulic diameter of a rectangular grille.

Extraction point at the ceiling

Layer depth below the extraction point: 8.00 m (ceiling height − distance to the extraction point − clear smoke height).

Is the extraction point near a wall?Select the vent position to evaluate plug-holing (E.9 / E.10).Extracted gas temperature (E.1)By default the flow rate is calculated without cooling credit. The weighted mean requires the reservoir area and a justification that it represents the extracted gas.

Air inlet (6.8)

Top level of the air inlet (m)Optional, from the floor. Enables the maximum inlet velocity and the minimum geometric inlet area to be calculated.

To check each inlet (Ci, velocity by distance to the layer, escape routes, inlet fans and vents of adjacent reservoirs: 6.8.2.11 to 6.8.2.16) add the inlets one by one. The list replaces the single level: the first inlet takes the level and the escape-route flag given here.

7. External conditions, curtains, suspended ceiling and pressure differential

Wind and adjacent buildings (6.7, Annex F)

Evaluate the wind overpressure and suction zones

Free-hanging smoke curtain (6.9, Annex G)

Calculate the deflection and length of the curtain bounding the reservoir

Suspended ceiling and plenum chamber (6.10, Annex H)

There is a suspended ceiling below the structural ceiling

Pressurised space in contact with the layer (7.3, Annex K)

There is a pressurised stair or lobby with leakage paths to the smoke layer

8. Exhaust slot, atrium and transient filling

Slot exhaust at the reservoir boundary (6.6.2.13, E.3 and E.4)

There is a powered slot exhaust instead of a boundary curtain

Transient filling of the reservoir (informative)

Estimate the filling time down to the design clear height

Not calculated

Calculation to UNE 23585:2017 (trial version)

Project details

Environmental parameters