Level 2 · White space · Concept rev D · 12 kW air first
The existing second floor at 801–809 W 4th St, laid out to fill with 12 kW air-cooled server racks up to the 9.25 MW of power available in Phases I and II, in Halls 1, 2 and 5 on the existing raised floor, and then to add GB300 or Vera Rubin rack-scale systems with in-row liquid cooling in Halls 3 and 4, on the bare slab with their own cooling. Hall 1 stays air-cooled and is built so rear-door cooling can take it to 50 kW a rack in Phase III. The structure is being engineered for very heavy racks, with loads carried down to columns that run to bedrock. Hover any area or numbered marker on the plan to see what it is.
Letters mark the rooms and halls; numbers mark the equipment every pod is built from. Room codes in grey are the zone names on the original plan.
W2F
Three bays of four rows: 336 air-cooled server racks at 12 kW on the existing raised floor. The first rows open in Phase I and the rest in Phase II. Hall 1 stays air-cooled; its 5 ft hot aisles leave room for rear-door heat exchangers (RDHx) that can raise racks to about 50 kW in Phase III, on chilled water run under the raised floor.
W2C
Two bays of four rows: 224 air-cooled server racks at 12 kW on the existing raised floor, with contained 5 ft hot aisles. Phase I (March 31, 2027) with the network hall, on the existing chilled-water plant.
W2E
80 air-cooled racks (up to 12 kW each) for spine switches, storage and management servers. It sits beside the existing telecom room where carrier fiber arrives. Phase I (March 31, 2027) with Hall 2, before any liquid cooling is in.
W2H north strip
One A and one B power distribution switchboard (PDS) per pod, including Hall 3’s (Phase III). Busway leaves here and runs over every row, air and liquid alike. A new wall separates it from Hall 2.
W2E annex
Treatment and filtration for the rack coolant loop, expansion tank, glycol make-up, RO water for the humidifiers, a spare CDU and pump cart, and a coolant store with spill kit. It sits on the liquid side, beside Hall 4.
W2M
Air-cooled server racks and GB300 or Vera Rubin racks (up to 2.2 tons) ship fully built. They are unpacked, proven here on a load bank or test CDU, then roll into a hall. Next to the freight elevators.
Existing PDU room
Panels for lighting, pumps, CRAHs and other building loads, kept separate from IT power. Reuses the existing PDU room between columns 1 and 2.
W2J
Two liquid-cooled pods of 32 GB300 or Vera Rubin racks on the bare slab, with in-row CDUs and their own facility-water risers. Phase III adds 10–13 MW here and/or as rear-door upgrades in Hall 1; both pods fill by Phase IV.
W2L / G3
Two future liquid-cooled pods (GB300 or Vera Rubin) on the slab, fed from their own electrical gallery to the south. Phase IV, once the 90 MW expansion is in place.
W2G4
PDS A and B switchboards for Hall 5 (built in Phase II) and Hall 4 (Phase IV).
W2A / B / Z
Two bays of four rows: 208 air-cooled server racks at 12 kW, beside Hall 2 so the air halls stay together, with switchboards at the south end. About 130 of them reach 9.25 MW in Phase II; the rest is spare air space. It could convert to liquid pods later.
Standard 600 × 1200 mm racks of air-cooled servers at up to 12 kW each, four rows to a 36 ft bay. Fronts face the cold aisles; backs face contained 5 ft hot aisles.
Two rows of 16 racks facing away from one enclosed hot aisle, on the slab in Halls 3 and 4. GB300 draws about 132 kW a rack, Vera Rubin up to 240 kW (600 × 1200 mm overall); both are liquid cooled.
Coolant distribution units. They swap heat between the building water and the clean coolant loop to the racks. About 1,800 kW each, 6 per pod, one more than the load needs (N+1).
The enclosed 5 ft aisle behind each pair of air rows, with doors at both ends, returning hot air to the CRAHs and fan walls. In Hall 1 the width leaves room for rear doors; in the liquid pods it also carries the TCS manifolds.
Main building water pipes, overhead, feeding the CDUs in Halls 3 and 4 only, so no facility water runs over the air halls. The risers just inside Hall 3 are an assumed location to confirm. Hall 1’s future rear doors would take chilled water under the raised floor instead.
Plug-in power bars above each half-row. A and B come from separate switchboards, so a rack keeps running if one side fails (2N).
415 V switchboards that feed the busways, one A and one B per pod. At least 4 ft of working space in front of each (NEC 110.26).
Computer room air handlers and fan walls at the ends of the aisles. They carry all the heat of the 12 kW air halls (9.25 MW by Phase II) and the leftover air heat of the liquid halls. About 200 kW each; the air halls need about 45–50 CRAHs or 25–30 fan walls.
Adiabatic ultrasonic humidifier on RO water. Holds 20–80% RH: too dry builds static, too humid risks condensation on cold pipes.
Leaf switch rack at each row end, linking every 8-rack scalable unit (SU) to the cluster fabric.
Overhead tray carrying fiber from the NET racks to the network hall and the telecom room.
In the air halls each 36 ft bay holds four rows: a 6 ft 3 in cold aisle on each column line, 5 ft contained hot aisles and a 4 ft cold aisle mid-bay. The liquid halls keep 23 ft cold aisles for rolling in 2.2-ton racks. End aisles are 14 ft at the north (gallery) end.
The existing wall on column line 8, with a plenum dam under the raised floor and a 1:12 ramp (18 in) between the raised-floor air halls and the slab-level liquid halls. Halls 2 and 5 could later convert to liquid pods; Hall 1 stays air.
Two numbers matter here. Floor capacity is what every drawn rack position would draw if filled, about 41 MW of IT as drawn: ≈10.2 MW of 12 kW air-cooled positions in Halls 1, 2 and 5 and the network hall (the power caps Phases I–II at 9.25 MW), and 30.7 MW of GB300 or Vera Rubin positions in Halls 3 and 4. Anticipated IT capacity is what the power supports: 2.7 MW today. The facility already has 20.5 MW of raw power, but much of it is held back by legacy 2N failover switching and wiring. Rewiring and new UPS systems should free about 9–11 MW of IT with no new utility power. Duke Energy feed increases of 2.5 MW and 14 MW then bring the facility to just above 37 MW of raw power and 22 MW of IT by Phase III. There is no plan to go further until Phase IV, an additional 90 MW of raw power from Duke Energy expected around 2030. Like the earlier increases, it connects through new infrastructure rather than the legacy switching. It is planned at a PUE of 1.2–1.3, adding about 69–75 MW of IT, roughly 88–93.5 MW in all. The liquid halls are on busway sized for 240 kW Vera Rubin racks; Hall 1’s busway is sized for 50 kW racks, so its rear-door upgrade needs no new power distribution.
| Area | System | Racks | Floor IT capacity |
|---|---|---|---|
| Hall 2 · W2C · Phase I | 12 kW air-cooled servers | 224 | 2.7 MW |
| Network hall · W2E · Phase I | Air-cooled IT | 80 | ≈1.0 MW |
| Hall 1 · W2F · Phases I–II | 12 kW air, RDHx-ready | 336 | 4.0 MW |
| Hall 5 · W2A/B/Z · Phase II | 12 kW air-cooled servers | 208 | 2.5 MW |
| Air halls + network | 9.25 MW used by Phase II | 768 + 80 | ≈10.2 MW |
| Hall 3 · W2J · Phase III on | GB300 / Vera Rubin | 64 | up to 15.4 MW |
| Hall 4 · W2L/G3 · Phase IV, ~2030 | GB300 / Vera Rubin | 64 | up to 15.4 MW |
| Floor capacity as drawn | 768 + 128 + 80 | ≈40.9 MW | |
| Hall 1 on rear doors at 50 kW (Phase III on) | RDHx | 336 | ≈16.8 MW |
| Halls 2 and 5 converted to liquid pods | GB300 / Vera Rubin | 128 | up to 30.7 MW |
| Phase | Ready for service | Raw power | IT capacity |
|---|---|---|---|
| Today | Now | 2.7 MW | |
| Phase I | Mar 31, 2027 | 4.05 MW | |
| Phase II | Sep 30, 2027 | 9.25 MW | |
| Phase III | Apr 30, 2028 | 37+ MW | 22 MW |
| Phase IV · 90 MW expansion (Duke Energy) | ~2030 | +90 MW → ≈127 MW | +75 MW → ≈93.5 MW |
The new Duke Energy feeds (2.5, 14 and 90 MW, 106.5 MW in all) connect through new infrastructure, not the legacy 2N switching, so they are planned at a PUE of 1.2–1.3. Phase IV’s 90 MW is shown at 1.2 (90 ÷ 1.2 = 75 MW IT). At 1.3 it would be about 69 MW. After it, the anticipated ≈93.5 MW of IT is more than Level 2 can hold even fully upgraded (≈79 MW: Hall 1 on rear doors at 50 kW, Halls 2–5 as liquid pods), so Level 2 can be fully built out, with power left for the rest of the facility. Phases I and II allow only 12 kW air-cooled racks: Phase I uses all 4.05 MW on the network hall, Hall 2 and the first rows of Hall 1, and Phase II reaches 9.25 MW with the rest of Hall 1 and part of Hall 5, on the existing chilled-water plant. Phase III adds 10–13 MW, capped at the 22 MW the power supports: GB300 or Vera Rubin in Hall 3, and/or rear-door upgrades that take Hall 1 toward 50 kW a rack. Hall 4 follows in Phase IV.
Air-cooled server racks: up to 12 kW and about 1 ton each (CPU, storage or lighter GPU servers); Hall 1’s rear doors would take them to about 50 kW. GB300: about 132 kW a rack. Vera Rubin: up to 240 kW, four 110 kW power shelves, 600 × 1200 × 2300 mm overall (GIGABYTE, Aivres; the MGX body is 1,068 mm deep plus a 132 mm rear extension), ~1,800 kW in-row CDU (GIGABYTE). Footprints, weights (≈2.2 tons Vera Rubin, a planning weight with margin, since NVIDIA gives about 4,000 lb) and floor loads (row-area averages ≈134 psf air, ≈297 psf liquid pods, ≈500 psf peak) are estimates. Future halls are anticipated to come online in Phase IV, once the 90 MW expansion is in place. Phase IV is an additional 90 MW of raw utility power under the pending Duke Energy application, expected around 2030, bringing the facility from just above 37 MW at Phase III to about 127 MW.
2N. The UPS is on P1, three floors down. Medium-voltage switchgear, generators and other support equipment are on P1, P2 and in the Annex. UPS feeders rise to the A and B switchboards for each pod in the north gallery (D), and those feed 415 V busway over every half-row.
Air halls: chilled-water CRAHs and fan walls with contained hot aisles; at 12 kW a rack, perforated tiles on the 18 in floor can carry part of the supply. Hall 1’s rear doors later run on chilled water under the floor. Liquid halls: facility water to in-row CDUs, a clean TCS loop to the cold plates, and CRAHs for the residual air.
20–80% RH non-condensing, with loop supply kept above room dew point. Leak detection under every pod, plus VESDA. The halls are protected by a pre-action sprinkler system, so the pipes over the racks stay dry until the fire detection system releases water into them. The new containment, overhead wiring, cooling and networking are all built to fire code.
The post-tension tendon layout and tendon-free zones for openings, beam depths within the 14 ft slab to slab, elevator door height and sill level against the raised floor, the added slab support design, riser space for UPS feeders from P1, facility water risers and heat rejection, final Vera Rubin specs from NVIDIA, CRAH and fan-wall capacity for 9.25 MW of air, chilled water for Hall 1’s rear doors, and the plenum dam and ramp at the boundary.
Phasing
Phases I and II allow only 12 kW air-cooled racks, so the plan above fills Halls 2, 1 and 5 with dense air-cooled rows on the existing raised floor until the 9.25 MW of Phase II power is used. Halls 3 and 4, on the east side next to the liquid-cooling support room, are kept for GB300 or Vera Rubin pods with their own cooling on the bare slab. Hall 1 stays air-cooled and can step up to about 50 kW a rack with rear-door heat exchangers in Phase III.
| Hall | Floor | Phase I | Phase II | Phase III | Phase IV |
|---|---|---|---|---|---|
| Network hall | 18 in floor kept | Air · 1.0 | Air · 1.0 | Air · 1.0 | Air · 1.0 |
| Hall 2 | 18 in floor kept | Air · 2.7 | Air · 2.7 | Air · 2.7 | → liquid pods possible |
| Hall 1 | 18 in floor kept, rear-door ready | Air · 0.4 | Air · 4.0 | Rear doors · toward 50 kW | Rear doors · ≈16.8 |
| Hall 5 | 18 in floor kept | — | Air · 1.6 | Air · 1.6–2.5 | → liquid pods possible |
| Hall 3 | No raised floor, on the slab | — | — | GB300/VR · part | GB300/VR · 15.4 |
| Hall 4 | No raised floor, on the slab | — | — | — | GB300/VR · 15.4 |
| Level 2 IT in use, MW | 4.05 | 9.25 | 19.3–22 | up to ≈79 |
MW are nominal IT. Phase I: the network hall (≈1.0 MW), all 224 racks of Hall 2 (2.7 MW) and about 33 racks of Hall 1, using all 4.05 MW. Phase II: the rest of Hall 1 (336 racks, 4.0 MW) and about 130 racks of Hall 5, reaching 9.25 MW; about 78 air positions stay spare. Phase III adds 10–13 MW, capped at 22 MW, as GB300 or Vera Rubin in Hall 3 (7.7 MW a Vera Rubin pod) and/or rear-door upgrades in Hall 1. Phase IV: Hall 4, Hall 1 fully on rear doors, and Halls 2 and 5 can convert. Like the capacity table, this assumes each phase’s IT capacity is available to Level 2.
Four rows of 600 × 1200 mm racks in each 36 ft bay: a 6 ft 3 in cold aisle on each column line, 5 ft contained hot aisles and a 4 ft cold aisle mid-bay, with 60 ft rows (56 ft in Hall 5). The existing 18 in raised floor stays for cabling and some tile supply. 12 kW racks weigh about 1 ton, so these halls need no new steel.
Hall 1 stays air-cooled. Rear-door heat exchangers on chilled water, piped under the raised floor, can take its racks toward 50 kW in Phase III (about 16.8 MW for all 336). Its 5 ft hot aisles stay about 3 ft 8 in wide with doors fitted, and its busway is sized for 50 kW racks.
GB300 or Vera Rubin pods of 32 racks on the bare slab with no raised floor, in-row CDUs, a TCS loop and their own facility-water risers just inside Hall 3, next to the liquid-cooling support room. The new beams under the rows go in only here.
The existing wall on column line 8, with a plenum dam under the raised floor so the air halls’ plenum stays sealed, and a 1:12 ramp (18 in) with a door so people and racks move between the raised floor and the slab.
Phases I–II put 9.25 MW of 12 kW air-cooled IT on the existing plant, about 10.4 MW with fans and lighting. The ten existing roof chillers (3,570 tons, ≈12.6 MW) can carry it, but with little margin: about 11.3 MW with one chiller out. Phase I’s 4.05 MW alone is comfortable. Confirm the plant’s real capacity and what else it serves.
About 125 cfm per kW at a 25 °F rise, so 4.05 MW needs ≈510,000 cfm (about 12–14 fan walls of 350–400 kW, with spares) and 9.25 MW needs ≈1.17 million cfm (about 27–30), far more than the CRAHs drawn today. They have to fit along the cold-aisle ends; this is the main space check for the air zone.
Unchanged switchboards. 12 kW air racks use a small part of a busway tap; Hall 1’s busway is sized for 50 kW racks for the rear-door upgrade, and the liquid halls’ for 240 kW.
12 kW suits CPU, storage and lighter air-cooled GPU servers. Rack-scale GB300 and Vera Rubin NVL72 are liquid-only, so they go in Halls 3 and 4.
Earlier layouts. Rev B, liquid-first: page · sheet · layout PDF · floor loads PDF. Rev C, ≈30 kW air pods west, Vera Rubin east: sheet. First air-first draft: sheet.
Structure
Liquid-cooled rack-scale systems weigh far more than conventional IT, and the next generations will be heavier still. Level 2 is being engineered for them. Rack loads come off the slab onto steel and go down columns that run to bedrock.
How the steel works together: each rack row sits on its own beam, the beams run continuously across the girders on column lines C, D and E, and the girders frame into the existing columns. The slab and racks are drawn lifted so the steel can be seen; in the building they sit directly on the beams.
The WEC floors are post-tensioned: steel tendons under high tension carry the slab, so cutting one is dangerous and costly to repair. Every new anchor, core or pipe opening is placed only after the tendons are mapped, and the new steel takes its load at the columns and existing beams instead of being drilled through the slab.
The Level 2 slab has already been strengthened with carbon fiber, raising its original load capacity.
A steel beam in the Level 1 ceiling directly under each rack row, carried by girders on the column lines that frame into the columns, so the rows no longer depend on the slab span. See the steel layout on the floor-load map.
Racks and CDUs sit on steel frames that spread their weight and carry it toward the column lines. This applies to every floor option, A through E. Frames and steel are sized with margin above today’s 2.2-ton racks, so heavier future NVIDIA generations fit the same positions.
Engineers have confirmed the columns are large, run down to bedrock and can carry far more than the building will ever hold. They anchor the whole load path.
Steel plates or heavy-duty panels run from the freight elevators to each row, rated for a 2.2-ton rack rolling on casters.
Next engineering steps: scan the slab (ground-penetrating radar or X-ray) to map the post-tension tendons, the carbon-fiber strips and the rebar, check tendon condition and anchorages, confirm the strengthened slab’s rated capacity, mark tendon-free zones for anchors and pipe openings, and set a design load for each rack position with margin for future racks: at least 5,000 lb (2.5 tons) per rack is suggested, since Kyber-generation racks (2027+) have no published weight yet and will be heavier. Then size the new steel and base frames. All of it is designed and stamped by the structural engineer of record. Commissioning equipment fits within the same design: liquid-cooled load banks for testing weigh up to about 1.1 tons, roughly half a rack. See the estimated floor load map (PDF).
Commissioning
Every hall is tested under simulated load before any tenant equipment goes in. Testing follows the five standard commissioning levels, from factory checks to a full integrated systems test of each hall.
| Level | Stage | What is proven |
|---|---|---|
| L1 | Factory acceptance | Major equipment (UPS, switchgear, generators, CDUs, chillers) is tested at the manufacturer before it ships. |
| L2 | Site acceptance | Each item is checked on arrival and after installation: right equipment, installed correctly, ready for power. |
| L3 | Pre-functional | Each system is started on its own. UPS, batteries, generators and switchgear are run under test load. |
| L4 | Functional | Each system is run under controlled load across its full range, including the liquid-cooling loops. |
| L5 | Integrated systems test | The whole hall is run end to end under simulated IT load, with power and cooling together, including failures and switchover. |
AI loads can jump in seconds. As they do, pumps, CDUs and chillers ramp up and draw more power themselves. Testing power and cooling separately can miss problems that only appear when they interact, so each hall’s final test runs both at once.
The liquid halls (Halls 3 and 4) are tested with load banks that heat the coolant loop, proving pump performance, flow, temperature rise across the loop and heat rejection. Air-heating load banks test the 12 kW air halls (Halls 1, 2 and 5) and the network hall at full air load.
Testing follows the build-out. Every phase is commissioned to L5 before tenants use it, and is isolated so that testing a new phase never disturbs halls already in service.
Test data are logged throughout. Tenants can receive the reports as evidence of the capacity and redundancy they are leasing.
Commissioning is carried out by an independent commissioning agent using load banks sized to each hall. Specific equipment and suppliers are chosen when each phase is scoped.
Structure
Estimated equipment weight across Level 2 at full build-out (Phases I–IV), averaged over 4 × 4 ft cells, with the concept steel that carries the rack rows drawn over it. The GB300 / Vera Rubin rows in Halls 3–4 are the heaviest, at about 500 psf; the 12 kW air halls average about 134 psf over their rows. Hover any cell to read its load, or any beam or girder for its spans.
Averages over the row area: 12 kW air bays about 134 psf, liquid pods about 297 psf. Rack weights come from this page (Vera Rubin 2.2 tons, air-cooled server racks about 1 ton); CDUs, switchboards and other equipment use planning estimates, not vendor data. Equipment weight only: no floor system, slab self-weight or code live load. The structural engineer of record sets design loads. Full sheet with every assumption and the steel layout (PDF).
| Item | Footprint | Weight, lb each | psf on its footprint |
|---|---|---|---|
| GB300 / Vera Rubin NVL72 rack600 × 1200 mm overall; 5,000 lb design allowance recommended | 2.0 × 3.9 ft7.9 sq ft | 4,400 · 5,000 design | 558 |
| Air-cooled server rack, 12 kW600 × 1200 mm; Halls 1, 2, 5 (Hall 1 rear doors to 50 kW) | 2.0 × 3.9 ft7.9 sq ft | 2,000 | 254 |
| In-row CDU, filled≈1.8 MW; liquid pods only, three per row over the D girder | 4 × 4 ft16.0 sq ft | 6,000 | 375 |
| PDS switchboard line-up415 V busway switchboard, electrical gallery | 14 × 4 ft56.0 sq ft | 9,000 | 161 |
| CRAH / fan-wallchilled water | 8 × 3 ft24.0 sq ft | 3,000 | 125 |
| Network (NET) rackone at each end of every row | 2 × 4 ft8.0 sq ft | 2,000 | 250 |
| Air-cooled IT racknetwork hall | 2 × 4 ft8.0 sq ft | 2,000 | 250 |
| Support / staging equipment | 12 × 5 ft60.0 sq ft | 3,000 | 50 |
| Humidifier | 2 × 3 ft6.0 sq ft | 500 | 83 |
Dashed gold end on the GB300 / Vera Rubin bar: the 5,000 lb design allowance (≈635 psf on its footprint). Not in the map: hung loads (facility-water headers in the Level 1 ceiling, TCS manifolds, containment), MEP allowances and code live load.
| Averaged over | psf |
|---|---|
| On one rack’s own footprint4,400 lb ÷ 7.9 sq ft | 558 |
| Peak 4 × 4 ft map celldarkest cells in the Vera Rubin rows | 497 |
| Liquid pod average over the rowsracks, CDUs, NET racks and hot aisle | 297 |
| 62,000 lb pod over a 320 sq ft containerspread over its whole base, aisles included | 194 |
| 12 kW air bay average, for comparison4 rows of 28 racks per bay, aisles included | 134 |
Steel under the rows (concept). Every liquid-cooled rack row sits directly on its own north–south beam in the Level 1 ceiling, so the slab only passes the load straight down and never has to span it. The beams run continuously over the lettered column lines and are carried there by east–west girders framed into the existing columns: in Hall 3 over lines C, D and E (36 ft + 24 ft spans) and in Hall 4 over F, G and H, with each row ending on the E girder and each pod’s CDU cluster centred over the D girder. The rows stay where they are: centring pods on the column lines would put columns in the hot aisles and cost a pod in each hall, because the hall walls sit on column lines. Concept quantities: 8 row beams (4 by Phase III, 4 in Hall 4), 12 girder runs, about 35 tons of new steel (≈18 tons by Phase III), sized roughly as W24 beams and W27–W30 girders at a 5,000 lb rack allowance. Rack positions are fixed before the steel is fabricated, and base frames get slotted adjustment so later racks still land on the beams. The 12 kW air halls and the network hall stay on the slab; Halls 2 and 5 would get beams only if they convert to liquid pods. The structural engineer of record sizes and stamps all of it. Hover any beam, girder or column for details.
Level 2 is 14 ft slab to slab, and racks are about 88 in tall. Today an 18 in raised floor carries the wiring and air cooling, and all of it can be redone. Below are five ways to use the height, from keeping the floor to removing it entirely. Water and power are kept apart in each, and services sit side by side instead of stacked.
Option A
Keep the existing 18 in raised floor as a wet plenum. Coolant runs below, power and fiber above, and facility water over the cold aisles only.
| Zone | Allow | Top at |
|---|---|---|
| Raised floor (wet plenum) | 18 in | 1 ft 6 in |
| Rack, air-cooled or Vera Rubin | 88 in | 8 ft 10 in |
| Hot-aisle containment roof | 4 in | 9 ft 2 in |
| Clear to sprinkler deflectors | 18 in | 10 ft 8 in |
| Sprinkler branch lines | 8 in | 11 ft 4 in |
| Left for slab above + beams | ≈32 in | 14 ft 0 in |
Today the floor carries the wiring and the air cooling. In the new layout it carries no air: every perforated tile is closed. The CRAHs (8) blow straight into the cold aisles and the hot-aisle containment returns. In rev D this is the floor of the 12 kW air halls (1, 2 and 5): at 12 kW a rack, perforated tiles in the cold aisles can carry part of the supply, with CRAHs and fan walls doing the rest.
Coolant (TCS) pipes run under the floor from each CDU and rise into the hot-aisle manifolds. Every joint sits over a drip pan, leak-detection rope runs the full floor, and each pod gets a drain point. Water stays under the racks and power stays over them.
A 2.0–2.2-ton rack on four casters puts about 1,000–1,100 lb on each wheel. That is more than most access-floor panels are rated to roll. The slab has already been strengthened with carbon fiber, but the rack rows will likely need more support. Engineers have confirmed the columns are large, run down to bedrock and can carry far more than the building will ever hold. So rows and CDUs sit on steel frames that carry their weight toward the column lines, with new steel under the slab if needed, instead of relying on the slab alone. Because the slabs are post-tensioned, that steel bears on the columns and existing beams, frames use as few slab anchors as possible, and every anchor or pipe opening goes in a scanned, tendon-free spot. Heavy-duty panels go along the roll-in path. The structural engineer sizes the steel.
All of today’s underfloor wiring and cooling can be redone, so it comes out before anything new goes in: cable, power whips and any piping. Then the plenum is cleaned, sealed and re-levelled. Power and network cabling return overhead.
Access from the freight elevators to the raised floor is already handled within the facility.
Option B
Replace the floor with a 30 in floor so every water pipe, facility headers included, runs below the racks. Overhead carries only busway, fiber and sprinklers.
| Zone | Allow | Top at |
|---|---|---|
| Raised floor (all water) | 30 in | 2 ft 6 in |
| Rack, air-cooled or Vera Rubin | 88 in | 9 ft 10 in |
| Hot-aisle containment roof | 4 in | 10 ft 2 in |
| Clear to sprinkler deflectors | 18 in | 11 ft 8 in |
| Sprinkler branch lines | 8 in | 12 ft 4 in |
| Left for slab above + beams | ≈20 in | 14 ft 0 in |
Facility water headers run under the cold aisles and coolant (TCS) branches under the hot aisles, so there is no water overhead at all. Drip pans sit under every joint, leak-detection rope runs the full floor, and each pod gets a drain.
30 in is a new floor system, because the existing 18 in grid can’t simply be raised. Rows and CDUs still sit on steel frames that carry their weight toward the column lines.
Only about 20 in is left for the slab above and its beams. That works only where beams are shallow or run along the hot aisles, so the beam survey decides it.
The facility’s existing access from the freight elevators is built for the 18 in floor. A floor 12 in higher means that access has to be reworked.
Option C
Remove the raised floor. Racks sit on the slab at elevator level, and every service, water included, hangs from the slab above.
| Zone | Allow | Top at |
|---|---|---|
| No raised floor, racks on slab | 0 in | 0 ft 0 in |
| Rack, air-cooled or Vera Rubin | 88 in | 7 ft 4 in |
| Hot-aisle containment roof | 4 in | 7 ft 8 in |
| Clear to sprinkler deflectors | 18 in | 9 ft 2 in |
| Sprinkler branch lines | 8 in | 9 ft 10 in |
| Left for slab above + beams | ≈50 in | 14 ft 0 in |
Rows sit directly on the carbon-fiber-strengthened slab, on steel base frames that carry their weight toward the column lines. New steel goes under the slab from Level 1 wherever the structural engineer needs it.
Facility water runs over the cold aisles, and coolant manifolds run over the hot-aisle containment, dropping to each rack. Busway goes over the racks and fiber at the rack fronts. Every water line sits over a drip tray with leak detection, and none runs directly above busway.
About 50 in is left for the slab above and its beams, so this works even if the beams turn out to be deep.
Racks roll straight from the two 6,000 lb freight elevators into the halls, with no ramp or lift. It is the fastest way to move 2.0–2.2-ton racks.
Water runs above the racks, and leak protection relies on drip trays instead of a floor plenum. The overhead space is the busiest of the three options to coordinate.
Everything here hangs from the slab above, which has carbon-fiber strengthening. Hanger anchors have to land between the carbon-fiber strips and never cut through them, so the strips get mapped before any layout is fixed.
Option D
Remove the raised floor and carry every overhead service on a steel frame that stands on the floor, so nothing is anchored into the strengthened slab above.
| Zone | Allow | Top at |
|---|---|---|
| No raised floor, racks on slab | 0 in | 0 ft 0 in |
| Rack, air-cooled or Vera Rubin | 88 in | 7 ft 4 in |
| Hot-aisle containment roof | 4 in | 7 ft 8 in |
| Clear to sprinkler deflectors | 18 in | 9 ft 2 in |
| Sprinkler branch lines | 8 in | 9 ft 10 in |
| Left for slab above + beams | ≈50 in | 14 ft 0 in |
A steel frame stands on the floor at each row pair, with posts just outside the rack fronts and a beam over the row. It carries the busway, fiber trays, coolant manifolds and containment roof. Nothing is anchored into the carbon-fiber-strengthened slab above.
The frame posts sit on the same steel base frames as the racks, which carry the load toward the column lines. Engineers have confirmed the columns have capacity to spare.
Frames can be prefabricated and set row by row, with services pre-hung, so most of the overhead work happens at floor level. Each pod can be built out in step with its phase.
There is no raised floor, so racks roll straight in from the freight elevators. Water is overhead on the frame, over drip trays, as in option C.
The frame posts take some aisle width at the rack fronts, and the frame itself is extra steel to buy and coordinate.
Option E
Remove the raised floor, run coolant in a shallow grated chase down each hot aisle, and bring facility water up from the Level 1 ceiling. Nothing wet runs overhead.
| Zone | Allow | Top at |
|---|---|---|
| Racks on slab (10 in chase in hot aisle only) | 0 in | 0 ft 0 in |
| Rack, air-cooled or Vera Rubin | 88 in | 7 ft 4 in |
| Hot-aisle containment roof | 4 in | 7 ft 8 in |
| Clear to sprinkler deflectors | 18 in | 9 ft 2 in |
| Sprinkler branch lines | 8 in | 9 ft 10 in |
| Left for slab above + beams | ≈50 in | 14 ft 0 in |
Instead of a whole raised floor, a shallow 10 in grated chase runs down each hot aisle. Coolant (TCS) pipes run inside it and connect to the back of each rack. The cold aisles, where racks are rolled in, stay at slab level.
Facility water headers run in the Level 1 ceiling and rise through a slab core at each CDU. Nothing wet is overhead on Level 2, and there is no raised floor.
Overhead carries only busway, fiber and sprinklers, which leaves about 50 in for the slab above and its beams.
The chase is a lined, sloped pan with leak-detection rope and a drain. Pipes in the Level 1 ceiling run over drip pans so a leak never reaches the floor below.
Each CDU needs a core through the carbon-fiber-strengthened slab, placed between the strips and approved by the structural engineer. It also needs room in the Level 1 ceiling for the headers.
All five options use the same racks, pods and phasing. They differ only in where the water runs, what hangs from the strengthened slab above, and how much height is left over.
| A · Keep the 18 in floor | B · Raise the floor to 30 in | C · No raised floor, services hung overhead | D · No raised floor, free-standing service frame | E · No raised floor, hot-aisle pipe chase | |
|---|---|---|---|---|---|
| Left for slab above + beams | ≈32 in | ≈20 in | ≈50 in | ≈50 in | ≈50 in |
| Water above the racks | Facility water, over the cold aisles | None | Facility water + coolant manifolds | Facility water + coolant manifolds, on the frame | None |
| Leak containment | Floor plenum | Floor plenum | Drip trays overhead | Drip trays overhead | Chase pan + drip pans in the Level 1 ceiling |
| Anchors into the slab above | Busway, trays, water | Busway, trays | Everything | None | Busway, trays |
| Access from the elevators | Already handled in the facility | Existing access reworked for +12 in | Level with the elevators | Level with the elevators | Level with the elevators |
| Floor work | Strip, reseal, steel under the rows | All-new floor, steel under the rows | Remove the floor, steel base frames | Remove the floor, set service frames | Remove the floor, build chases, core the slab |
| Best if | Beams leave ≈32 in or more | Beams are shallow (≈20 in) | Any beam depth | The slab above should not take anchors | Level 1 ceiling has room and slab cores are approved |
The beam survey and the carbon-fiber layout decide it. These are planning allowances, not survey dimensions. 14 ft is taken as top of slab to top of slab, with about 8 in for the slab above.
Every short form used on the plan and in this guide.
Vendor and press sources for the equipment sizes, weights and ratings on this page. Weights for switchboards, network racks, humidifiers and support equipment are planning estimates where no published figure was found.