Level 2 · Raised-floor white space · Concept rev A
The existing second floor at 801–809 W 4th St, laid out for NVIDIA rack-scale systems with in-row liquid cooling and 2N overhead busway. 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
The highest-density hall. Three pods of 32 Vera Rubin racks, all liquid cooled, fed by in-row CDUs and overhead A/B busway. Pod 1A comes online in Phase III; pods 1B and 1C in Phase IV.
W2C
Two pods of 32 GB300 NVL72 racks, online in Phase II (September 30, 2027), when the new liquid-cooling loops are in. Same rack footprint as Vera Rubin, so the hall converts in place.
W2E
80 conventional air-cooled racks for spine switches, storage and management servers. It sits beside the existing telecom room where carrier fiber arrives. This is Phase I (March 31, 2027): it runs air-cooled on the existing chilled-water plant, before any liquid cooling is in.
W2H north strip
One A and one B power distribution switchboard (PDS) per pod. Busway leaves here and runs over every row. 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.
W2M
GB300 and Vera Rubin racks ship fully built at 2.0–2.2 tons. They are unpacked, connected to a test CDU and load bank, and proven here before rolling 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 · future
Two future pods, shown dashed. Space and routes are reserved; anticipated to come online in Phase IV, once the 90 MW expansion is in place.
W2L / G3 · future
Two future pods, shown dashed, fed from their own electrical gallery to the south. Anticipated to come online in Phase IV, once the 90 MW expansion is in place.
W2G4 · future
PDS A and B switchboards for Future Hall 4, built in Phase IV.
W2A / B / Z · future
Two future pods, shown dashed, with switchboards at the south end of the hall. Anticipated to come online in Phase IV, once the 90 MW expansion is in place.
The 16 hatched racks, the first GB300s to go in once the liquid-cooling loops arrive in Phase II, with their network racks. Each GB300 NVL72 rack is 600 × 1068 mm and draws 132 kW nominal, about 155 kW at peak.
Two rows of 16 racks facing away from one enclosed hot aisle. Each Vera Rubin rack draws up to 240 kW and is fully 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 pod, with doors at both ends. It traps leftover hot air and carries the TCS supply and return manifolds to every rack.
Main building water pipes, overhead, feeding every CDU in Halls 1 and 2. The risers at the west wall are an assumed location to confirm.
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 at the ends of the cold aisles. They take the leftover air heat, mostly from GB300. About 200 kW each, 8 per hall.
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.
Every building column sits inside a 24 ft cold aisle. It is wide enough to roll in a 2.2-ton rack. Hot aisles are 5 ft and end aisles 18 ft 10 in.
Two numbers matter here. Floor capacity is what every drawn rack position would draw if filled, about 32.6 MW of IT in Halls 1–2 and the network hall. 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 19 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. Every position is built for a 240 kW Vera Rubin rack.
| Area | System | Racks | Floor IT capacity |
|---|---|---|---|
| Hall 1 · W2F | Vera Rubin NVL144 | 96 | 23.0 MW |
| Hall 2 · W2C | GB300 NVL72 | 64 | 8.4 MW (9.9 peak) |
| Network hall · W2E | Air-cooled IT | 80 | ≈1.2 MW |
| Floor capacity, Halls 1–2 + network | 160 + 80 | ≈32.6 MW | |
| Future Halls 3–5 · Phase IV, ~2030 (with pods 1B + 1C) | Vera Rubin-ready | 192 | up to +46.2 MW |
| Floor capacity with Future Halls 3–5 | 352 + 80 | ≈78.8 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 | 19 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 with Future Halls 3–5 built (≈78.8 MW floor capacity), so Level 2 can be fully built out, with power left for the rest of the facility. Until then, the power supports 19 MW of IT, so of Level 2’s ≈32.6 MW floor capacity, Hall 2, the network hall and Pod 1A come first, and pods 1B and 1C wait for Phase IV. Phase I runs on the existing air-cooled plant, so it brings the air-cooled network hall online (≈1.2 MW). The new liquid-cooling loops arrive in Phase II, and all of Hall 2’s GB300 pods follow then. Together they come to about 9.6 MW nominal, slightly above Phase II’s 9.25 MW, so Hall 2 fills to the power available.
GB300: 132 kW nominal, ~155 kW peak, busway sized for 192 kW (HPE). Vera Rubin: up to 240 kW, four 110 kW power shelves, ~1,800 kW in-row CDU (Gigabyte). Footprints, weights (≈2.0 tons GB300, ≈2.2 tons Vera Rubin), floor loads (pod averages ≈281–302 psf over the rows, ≈550 psf on Vera Rubin rows) and the GB300 air/liquid split 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.
Facility water to in-row CDUs, a clean TCS loop to the cold plates, and chilled-water CRAHs for residual air through hot-aisle containment.
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, and final Vera Rubin specs from NVIDIA.
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.
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.
Steel beams in the Level 1 ceiling under each rack row, framed into the columns, so the rows no longer depend on the slab span alone.
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. 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.
Halls 1 and 2 are liquid cooled, so load banks that heat the coolant loop are used there. They prove pump performance, flow, temperature rise across the loop and heat rejection. Air-heating units cover the leftover air heat in Hall 2 and the air-cooled network hall.
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. The Vera Rubin rows are the heaviest, at about 550 psf. Hover any cell to read its load.
Pod averages over the row area: Hall 2 pods about 281 psf, Hall 1 pods about 302 psf. Rack weights come from this page (Vera Rubin 2.2 tons, GB300 2.0 tons); 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 (PDF).
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, GB300 NVL72 / 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. The small air load, mostly from GB300, doesn’t need an underfloor supply.
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, GB300 NVL72 / 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, GB300 NVL72 / 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, GB300 NVL72 / 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, GB300 NVL72 / 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.