IFC showcase: Sprinklers in the ceiling plenum

3D model

The viewer opens sprinkler-plenum.glb, the glTF that NativeBIM writes from the IFC file. The IFC file is sprinkler-plenum.ifc.

What is in the model

Requirements

The model does not yet meet every requirement of an interior. Each is measured on the model’s geometry by casting rays at it from sample points 0.355 m apart.

Drawing set

Draft drawing set generated from the model: sprinkler-plenum-drawings.pdf (PDF, 4 sheets).

• G-001 COVER SHEET AND SHEET INDEX
• A-101 LEVEL 1 FLOOR PLAN
• A-102 LEVEL 1 REFLECTED CEILING PLAN
• A-601 DOOR, ROOM FINISH AND AREA SCHEDULES

Elevations are not generated yet, so this drawing set has plans and schedules only. Sections are not generated yet, so this drawing set has plans and schedules only.

Sprinkler layout, hydraulics and clashes

Preliminary, not engineering and not for construction (ADR-012). Preliminary sprinkler layout and hydraulic screening, not engineering and not for construction. Heads, pipe sizes and pressures come from simplified rules and configurable default values taken from public summaries of NFPA 13, not from the standard itself; a qualified fire protection designer lays out and calculates the system under the edition the authority having jurisdiction adopts. Outputs are drafts for review by the licensed professional of record.

The numbers on this page are computed by the build, not typed in. Reproduce them with node tools/showcase/build.js sprinkler-plenum; a second run writes the same bytes.

26 heads in five spaces, 99.8 m of sprinkler pipe. The clash detector tested every element with a body against every other: 0 hard clashes and 0 clearance violations at 50 mm with the heads and pipes in place. Straight branch lines at one elevation that ignore the ducts, from the same risers to the same heads, have 68 hard clashes.

Most remote area. The governing room is 105 Break room: the area of operation is 6 heads over 99.8 m2, the sprinkler flow 586.9 liters per minute and the demand with the hose stream 965.4 liters per minute (255.0 gpm). The calculation needs 3.49 bar at the riser; the assumed supply gives 4.92 bar at that flow, a margin of 1.43 bar.

Each room is smaller than the 139.4 m2 design area, so the area of operation is the whole room. A real calculation would extend the area into the next room and the demand would be higher; the engine calculates one room at a time and treats each as its own zone. The rooms are not calculated together.

Obstruction rules. On the built floor the beams, the supply ducts, the cold and hot water pipes and the cable tray all hang above the deflectors, so they obstruct the branch lines and not the spray; the router passes them with 50 mm clearance. The diffusers hang below the ceiling and the light panels sit in it: the layout moved 8 heads clear of them, and 0 heads sit inside a light panel. In the what-if with the ceiling left out, the beams that run across a room cut it into bays (3 extra bays over the five rooms) and the ducts push heads out to the three times rule's distance (9 heads move, with 32 heads in all). The what-if is a layout only and is not clash-checked.

The op reads beams, members, ducts and cable carriers as obstructions to the heads, and not lights or air terminals. This showcase hands the diffusers and light panels to the layout while the op runs (scenario.js, withCeilingObstructions): a head keeps 0.1 m clear of a light panel and 0.6 m clear of a diffuser, and a tie between two ways out of a panel is broken toward the nearest wall. These two rules are choices made for this sample, not NFPA 13 rules.

NFPA 13 values are recalled from public summaries and cited by section. None is checked against the publisher's document (verified: false). The authority having jurisdiction adopts the edition that applies, and a qualified fire protection designer lays out and calculates a real system. The water supply is an assumption. The engine is a preview.

Colors in the 3D model: the sprinkler heads and pipes are yellow (an IFC surface style), apart from the supply air, cold water, hot water and cable tray colors of the plenum showcase.

Out of scope: gridded and looped systems, dry and preaction systems, other hazard classes, the standard's rectangle of operation along the branch lines, pumps and tanks, hangers and seismic bracing, and head-to-ceiling-tile detailing.

• Hydraulic report (text), the notice at the top and the end
• Hydraulic report (JSON), the notice in the notice field
• BCF of the clashes of the straight-line layout (68 clashes in 15 topics), the notice in every topic
• IFC of the straight-line layout the BCF refers to

Sources

Where each dimension comes from. Anything marked as chosen for the sample is an assumption, not a measurement.

• Sprinkler engine: head layout per room, the router for the branch lines, Hazen-Williams most remote area balanced by Newton's method, and the layoutSprinklers op. packages/core/src/mep/sprinkler, packages/core/src/edit/ops/sprinkler.js; docs/MEP-AUTHORING.md, section Sprinkler layout and hydraulics.
• Light-hazard layout and design numbers: protection area per head, spacing, distance to walls, density, design area, hose stream allowance, minimum head pressure, the three times rule for obstructions. NFPA 13 (2019 edition numbering), sections 10.2.4.2.1, 10.2.5, 10.2.7.2.1.3, 19.3.3.1 and 28.2.4.10.1, recalled from public summaries and not checked against the publisher's document (verified: false). The tables on this page list each value with its section. The authority having jurisdiction adopts the edition that applies..
• Pipe friction: Hazen-Williams with C 120 for black steel; fittings as equivalent lengths from L/D ratios. Williams and Hazen, Hydraulic Tables; Crane Technical Paper 410, Flow of Fluids Through Valves, Fittings, and Pipe.
• Water supply at the riser: static 5.5 bar, residual 4.2 bar at 1500 liters per minute. Chosen for this sample as an assumption. It is not a flow test of any building's supply. A flow test at the real site sets the real curve..
• Building: the 24 m x 16 m office floor of the plenum showcase with five steel beams, 45 recessed troffers, eight diffusers, supply ducts, cold and hot water pipes and a cable tray routed through the plenum. showcases/clash-free-plenum (floor.js, scenario.js). No real building is represented..
• Ceiling lights and diffusers as obstructions to the heads: a head keeps 0.1 m clear of a light panel and the three times rule's distance from a diffuser. Chosen for this sample. The op reads beams, members, ducts and cable carriers; lights and air terminals are handed to the layout by showcases/sprinkler-plenum/scenario.js..
• BCF 2.1 file of the clashes of the straight-line layout. buildingSMART International, BCF 2.1.

Built 2026-10-28 with node tools/showcase/build.js sprinkler-plenum. Re-running the command gives the same bytes.

Notices