Fire Protection
One building
This 23-room industrial program contains 52,200 square feet and generates 452 schematic sprinkler heads. Area, room use, occupant load and water demand all come from this same building.
Scroll from the whole building into a room and back out to its water supply. The drawing changes scale while the demand and pump comparison stay in view. Drag the building edges to resize it, the pipe mark to change its internal diameter, or the riser top to raise the sprinkler plane. Heads, branches, pressure losses and pump ratings follow the same building. Your edits stay with the building; Play follows the article’s examples around them.
What the separations change
Assume, for comparison, that the marked seams qualify as separations. The room graph divides into 11 groups; the largest has 20,000 square feet. The whole building still has 52,200 square feet.
The archived seams are unrated or one- and two-hour fire barriers. This example does not turn them into verified fire walls. Under NCTCOG’s recommended 2024 IFC amendment, §903.2.11.9 Option B, fire walls do not define separate buildings for this provision. Its boundary includes exactly 6,000 square feet; qualifying open parking garages are excepted. Actual city adoption still matters.
Count without the separations
Switch off those separation assumptions. The rooms reconnect in the comparison and the largest group becomes 52,200 square feet. The physical room program, schematic head quantity and regional whole-building count stay the same. The demand and pump comparisons stay level too: changing the counting assumption does not change the hydraulic path.
Tap a seam to change its assumption. The group areas recalculate from the connected rooms. A smaller group is useful only when the applicable rule actually counts that group.
When evidence is missing
The building does not shrink when an adoption record is missing. Its area remains known; whether this selected amendment applies remains open. Changing that evidence leaves the modeled flow and pressure requirement unchanged.
Move the evidence marker between unknown, excluded and confirmed. A documented exclusion leaves this amendment out. Missing evidence leaves its answer unresolved. Neither establishes the building’s overall sprinkler requirements.
Confirm the area rule
The confirmed teaching record can compare the same 52,200 square feet with the inclusive 6,000-square-foot boundary. The geometry has not changed; the evaluator now has enough evidence for this one comparison.
A jurisdiction’s actual adoption, applicable exceptions and other triggers still need their own basis. The original evaluator distinguishes inherited profile values, city records and session edits.
Raise an occupied floor
Lift this modeled program to an occupied floor 35 feet above fire-department access. Its 525 modeled occupants exceed the separate 30-person boundary. The teaching height check needs both conditions.
This generated example also raises the sprinklers from 30 to 65 feet above the pump, assumed at the access datum, preserving the 30-foot rise above the floor. Occupied-floor height and sprinkler elevation use distinct references; actual floor populations and pump location must establish the project case.
Move a room wall
Return the program to its original ground-floor position. Move the open office’s shared wall 15 feet: its area falls from 3,600 to 2,700 square feet, its modeled load from 24 to 18 people, and its grid from 16 to 12 heads.
The adjacent offices receive those 900 square feet and gain four grid heads. The building still totals 52,200 square feet and 452 heads. The receiving rooms remain visible as the drawing moves closer. With the same hazard criteria and hydraulic path, this transfer leaves the operating demand and pump screen unchanged.
Change the room’s use
Restore the wall and use the same room for meetings. The model factor changes from 150 to 15 square feet per person: 24 becomes 240. Its light-hazard grid remains at 16 heads; total modeled occupants rise from 525 to 741.
The occupant count changes; this example keeps the light-hazard sprinkler criteria and water path, so its operating flow and pump screen stay the same. This flags an assembly review candidate, not an automatic occupancy classification. Actual use, area basis, exceptions and egress need confirmation.
Grow the building
Stretch the envelope from 340 by 170 feet to 425 by 210 feet. The room program grows from 52,200 to about 80,603 square feet. Its sprinkler grid grows from 452 to 719 heads, and the governing drawn route grows from 499 to about 622 feet, including the 30-foot riser. The array keeps its design pitch as the rooms change size: 15 feet in the light-hazard rooms and 10 feet in the ESFR rooms. Smaller rooms shed rows and columns; their edge bays absorb the remainder. A room narrower than one pitch gets a centered head along that axis. Operating demand is a different calculation: each hazard family has its own assumed remote case and hose allowance. Those independent cases are not added together. Drag the storage-clear-height mark to change the archived storage probe and recalculate the family cases; it scales the storage spaces without moving the office ceiling or the sprinklers above the pump.
The archived ESFR example uses twelve K25.2 heads at 50 psi, giving about 2,138.3 gpm plus 250 gpm for hose: 2,388.3 gpm at the pump. Commodity, storage arrangement, ceiling and sprinkler listing must establish the actual design. The archived model supplies these schematic assumptions.
Increase the pipe size
Keep the building and demand; increase the equivalent internal pipe diameter from 6 to 8 inches. On the enlarged building’s approximately 622-foot C120 route, the ESFR case loses 23.2 psi instead of 94.1 psi. Required boost falls from 122.8 to 51.9 psi. Drag the diameter mark on the highlighted pipe: its thickness, color, adjacent loss bar and pump comparison change together. Blue-to-orange color records cumulative friction and elevation loss along the route on a fixed 0–150+ psi scale. Moving water markers show direction; their speed is illustrative. Play and Pause control both the markers and the article examples.
The pressure stacks keep the same axis. They show terminal pressure, friction, elevation and an 8 psi device allowance against available water plus required boost. The example supply is 70 psi static and 50 psi at 2,000 gpm, referenced to pump suction. The comparison extrapolates beyond that test flow. The U.S. Fire Administration’s water-supply text describes the Hazen–Williams relationship used here.
Raise the sprinklers
Keep the 8-inch pipe and raise the sprinklers from 30 to 70 feet above the pump. Drag the top of the riser upward. The sprinkler plane lifts above the pump datum. Forty more feet adds 17.3 psi of elevation pressure and about 1.5 psi of pipe friction, raising required boost from 51.9 to 70.7 psi. The room program and operating demand stay the same.
Among five archived Aurora 913 diesel-pump ratings, the enlarged building’s 6-inch route points to 130 psi, the larger pipe to 55 psi, and the higher sprinklers to 75 psi, each at a rated 2,500 gpm. These are rating screens to investigate. A full curve, pressure limits, driver capacity and current listing still need qualification; a rating is not the available head at every flow.
Improve the water supply
Keep the 8-inch pipe and 70-foot sprinkler elevation. An illustrative 125/110 psi test at 3,000 gpm provides 115.2 psi at the critical demand against 113.0 psi required. Every modeled case is covered without added pump head; the baseline stays visible beside it.
Drag the water, pipe or elevation marks and watch the pressure gap and archival rating change together. The persistent comparison uses the original building as its start; the detailed pressure stacks isolate the water-path changes within the current building. Inconsistent or exhausted supply inputs leave the duty unresolved. The colored line is the greatest-pressure-gap family’s longest generated route. Each family is checked separately, at full remote-case flow along its route and a uniform equivalent internal diameter. The faint branches show distribution, not solved branch flows. Fittings, actual branch sizes and network balance still need a detailed design; this comparison does not select listed equipment. Measured water data, the actual pipe network and manufacturer curves must establish the final design.