Datacenter
Qualifying a data center for liquid-cooling retrofit work
Qualify the workload, water, power, access, and shutdown plan before pricing a liquid-cooling retrofit. Turn each unknown into a survey task with a named owner.
Direct answer
Qualify a data center for liquid-cooling retrofit work by confirming the proposed information technology (IT) platform and load, the complete heat-rejection path, usable electrical capacity, structural and service access, and an owner-approved shutdown and commissioning plan. Request the drawings, trends, equipment requirements, and operating restrictions before pricing construction. Exterior campus evidence starts a prospect list; internal records and a site survey establish the scope.
On this page
What makes a liquid-cooling retrofit worth a site survey?Which records do you need before the first visit?What can exterior campus evidence actually establish?Does the proposed rack platform fit the cooling concept?Can the facility water system carry the new load?Can power, structure, and access support the installation?Who controls the shutdown and the operating risk?Commissioning scope and handoff boundariesWorked example: an eight-rack qualification packageAssessment deliverables and exclusionsHow do you choose bid, survey, hold, or pass?What to documentCommon mistakesField qualification checklistStandards and referencesUnits and termsFinding retrofit accounts in your service areaMethodologyOpen the related tool for the calculation, checklist, or packet.
HydroTest DCPressure-test package math, hold timing, thermal drift verdicts, witness signatures, and PDF/CSV records.FieldOS by AnvilfieldOffline-first FieldOS for job photos, proof packets, property memory, calculations, teams, billing, and owner-ready reports.What makes a liquid-cooling retrofit worth a site survey?
Qualify a retrofit survey by identifying the proposed IT equipment, its room, the operating date and the person authorizing the review. Request the rack schedule and permission to investigate the cooling connection. A large outdoor cooling yard alone does not establish a retrofit project.
Track visible campus, verified operator, confirmed project need, scoped assessment and approved construction package separately. Offer a records review or walkdown when the project is not developed enough for a construction price.
Ask whether the job is a pilot row, a tenant installation, or a staged hall conversion. Those lead to different boundaries around shared plant, commissioning, and future capacity. Record the actual decision maker and procurement route. If the caller cannot identify the platform or obtain facility access, retain the account for follow-up and keep construction pricing on hold.
Which records do you need before the first visit?
Send one document request with a due date and an owner for each missing item. Ask for the revision used by operations, then compare it with the installed labels during the walk. Mark a drawing as unverified until that comparison is complete. A stale diagram can send your estimator to the wrong header or the wrong electrical panel.
Request representative operating trends, including the conditions the owner considers limiting. A quiet morning reading does not settle summer performance or performance with equipment unavailable. Record the measurement interval, instrument or sensor identity, operating mode, and which loads were running. If trends are unavailable, price a measurement plan separately rather than inventing peak demand.
| Record | Question it resolves | Requested owner |
|---|---|---|
| Rack schedule and vendor requirements | What load, fluid, flow, temperature, and connection are proposed? | IT lead and equipment supplier |
| Piping diagrams, plant schedules, and trends | Where can heat enter the facility system, under which operating conditions? | Facility mechanical lead |
| Electrical one-line and load study | Which power path can support racks and cooling auxiliaries? | Electrical engineer |
| Structural records and delivery drawings | Can the route, floor, and supports carry the installed and moving loads? | Owner and structural engineer |
| Operating procedures and work restrictions | Who approves isolation, outages, access, and restoration? | Operations manager |
| Commissioning requirements and scope matrix | Who furnishes, connects, tests, witnesses, and accepts each interface? | Project manager and commissioning agent |
What can exterior campus evidence actually establish?
Use dated exterior observations to locate campuses, note visible cooling or power infrastructure, and identify a reason to investigate. Keep the image date, observation date, location, and source with the record. Describe the observation narrowly: visible equipment yard, apparent addition, or construction activity. Do not turn an equipment shape into a capacity or condition finding.
Exterior evidence does not establish the internal cooling architecture, a usable water connection, the installed server platform, or a funded retrofit. Even a correctly identified cooling tower does not tell you which hall it serves or whether any capacity is available. Verify the site operator through public records or the operator's own information, then ask the authorized facility team about the actual project.
Keep one campus record with separate buildings and phases. Leave interior scope unknown until the facility team supplies dated evidence. Several views of one expansion should not create several forecast opportunities.
Does the proposed rack platform fit the cooling concept?
Start with the equipment requirements, then trace the heat outward. Direct-to-chip cooling moves heat through cold plates. Rear-door heat exchangers capture rack exhaust heat. Immersion changes the equipment and fluid-handling arrangement. DOE's 2024 design guide distinguishes these approaches; they are separate scopes, not interchangeable items on a quote.
Identify the coolant distribution unit, or CDU, and its rejection method. A liquid-to-liquid CDU transfers heat into a facility fluid system. A liquid-to-air CDU puts heat into the room, where the existing cooling must remove it. The latter can avoid a new facility-water connection at the CDU, but it does not create room-cooling capacity. Confirm that distinction before offering it as a retrofit shortcut.
Get the platform's heat split. NVIDIA's DGX GB compute-tray description identifies liquid-cooled CPUs and GPUs with air-cooled networking and storage components in those trays. That does not classify every network device in the rack. Obtain the proposed platform's liquid and air duties, operating limits, connections and service clearances.
Best Practices Guide for Energy-Efficient Data Center DesignDGX GB rack configuration, cooling, and accessCan the facility water system carry the new load?
Trace both fluid circuits on a marked drawing. The facility water system, or FWS, carries heat toward the building's rejection equipment. The technology cooling system, or TCS, serves the IT equipment. In the liquid-to-liquid concept considered here, the CDU heat exchanger separates them. Identify the actual connection points and the performance required on each side.
Ask for usable capacity at the required entering temperature and operating condition, not installed nameplate capacity. Identify the governing hot-weather and maintenance cases with the design engineer. Include the residual air load and the other equipment sharing the plant. Then ask whether the proposed branch can deliver the required flow at its available differential pressure. Thermal headroom alone does not answer the hydraulic question.
Vertiv's deployment guide treats existing cooling, piping, fluid compatibility, and physical routing as assessment items. Turn those into assigned tasks: verify valve positions and branch routing, obtain water samples, check filtration arrangements, and compare pump and heat-exchanger performance with the proposed duty. Keep facility-water samples separate from technology-coolant requirements.
Request an approved materials and fluid schedule. Do not prescribe a generic glycol concentration, filtration rating, pressure-test multiplier, or supply temperature during qualification. Obtain the selected equipment's limits and the project's acceptance basis. Include condensation protection and the permitted temperature relationship to room dew point in the controls review. Missing limits belong on the unresolved-items list.
Existing-facility assessment, CDU heat rejection, and compatible materialsCan power, structure, and access support the installation?
Put an electrical reviewer on the qualification team. Schneider Electric's power-retrofit paper recommends a load study and addresses distribution constraints and changing artificial intelligence (AI) load profiles. Ask for capacity through the complete proposed path, including the uninterruptible power supply, distribution equipment, rack feeds, and cooling auxiliaries. An empty breaker position is not a completed capacity study.
Record which power source serves the CDU, its controls, facility pumps, and rejection equipment. Have the design team define continuity through transfers and restart behavior. Do not infer cooling ride-through from the presence of standby generators. List the electrical study and integrated demonstration needed to close the question.
Walk the delivery and service routes with dimensions in hand. Include packaged and operating weights, concentrated support loads, moving loads, elevator limits, turns, thresholds, pipe supports, and removal space. Ask the structural engineer to approve the actual arrangement. A room's average floor loading does not settle a rack foot or a delivery crossing.
Check the rear service space against the selected rack, piping, and cabling arrangement. NVIDIA locates manifold connections and other access points at the rear of its documented GB racks. Photograph proposed obstructions with permission and mark them on the layout. A unit that fits in plan still needs room to connect, isolate, and repair.
Schneider Electric: Retrofitting Existing Power Systems for AI Clusters, PDFWho controls the shutdown and the operating risk?
Identify who controls each room, shared header, electrical feed, and maintenance window. In a colocation facility, the tenant requesting more compute may not control the building systems. ASHRAE's liquid-cooling white paper discusses service agreements that restrict water near racks. Read the site's actual agreement and obtain the responsible operator's position before developing an intrusive scope.
Ask operations to identify permitted isolation points, protected neighboring loads, change-control requirements, restoration checks, and the person who can stop the work. Record outage duration and scheduling as unapproved until operations accepts them. Price escorts, access delays, temporary arrangements, and additional mobilizations when the agreed work plan calls for them.
Treat the survey as a separate activity from functional testing. A walkdown does not authorize valve operation, pressure testing, sensor wetting, control overrides, or interruption of production cooling. Put those activities in a later approved method of procedure with boundaries, witnesses, and recovery steps. Qualification earns enough information to write that procedure.
Emergence and Expansion of Liquid Cooling in Mainstream Data CentersCommissioning scope and handoff boundaries
Use liquid-loop commissioning requirements to expose missing scope before tender. The Open Compute Project (OCP) integration and logistics guidance covers preparation, inspection, documented installation, and staged commissioning. Build a responsibility matrix around those interfaces. Name who owns facility piping, CDU startup, rack manifolds, IT connections, controls integration, and final acceptance.
Define the cleanliness and pressure-test boundaries with the equipment suppliers and engineer. Identify how sensitive components will be isolated, which procedure and fluid apply, where sampling occurs, and who accepts the result. Assign flushing equipment, temporary connections, consumables, drainage, and waste handling. Each needs a responsible party even when supplied under another contract.
Price leak detection as a complete response chain. Locate the detection and containment, identify the alarm destination, and document the approved operator or automatic action. Do not conclude every alarm should stop every pump. The approved response must consider the affected zone and the cooling consequence for other loads. Agree the proof method before anyone demonstrates it.
Specify the load simulation, instrumentation, test conditions, witnesses, and pass criteria. Include the failures and maintenance states the design must demonstrate, with an approved recovery plan. A successful startup is not evidence that a shared loop remains available during maintenance. Keep final acceptance separate from the earlier qualification decision.
Liquid Cooling Integration and Logistics White Paper| Boundary | Assign before pricing | Required handoff evidence |
|---|---|---|
| Facility branch to CDU | Piping installer, facility operator, and engineer | Marked connection, test limits, balance, and available duty |
| CDU to rack and IT | CDU supplier, rack integrator, and IT vendor | Approved fluid, cleanliness, connections, and flow requirements |
| Controls and leak response | Controls contractor and operations | Point list, response sequence, and witnessed alarm path |
| Loaded integrated test | Commissioning agent and all affected trades | Approved scenarios, measured results, exceptions, and acceptance |
For liquid-cooling retrofit, PorchRocket's Asset Search finds and monitors cooling towers visible from above anywhere in the lower 48.
Worked example: an eight-rack qualification package
Anvilfield research models a typical screening and pricing case in US dollars. The case uses eight new racks in currently vacant positions, each drawing 60 kW simultaneously at the screening duty. 80 percent of that heat reaches liquid and 20 percent reaches room air. Use no diversity, equipment removals, future growth, or energy savings credit.
The case uses a liquid-to-liquid CDU, 8 kW of pump input entirely added to the liquid heat path, and one shared plant serving both the new liquid branch and room cooling. Ignore piping heat gain and all other auxiliary heat for this preliminary balance. A provisional worksheet shows 500 kW of spare plant duty at the stated facility temperature; its maintenance condition has not been demonstrated.
The case uses single-phase water-like properties on both sides for the energy balance: density 1.00 kg/L and specific heat 4.18 kJ/(kg K), constant over the temperature range. Technology coolant enters racks at 32 C and returns at 42 C. Facility water enters the CDU at 28 C and returns at 36 C. Confirm these operating points with the vendor, then select coolant chemistry and equipment.
The rack load is 8 x 60 = 480 kW. Liquid takes 384 kW and air takes 96 kW. The CDU facility-water duty is 384 + 8 = 392 kW. The shared plant sees 392 + 96 = 488 kW before the omitted heat additions. That leaves only 12 kW against the provisional 500 kW spare figure, before engineering allowances or any correction to that figure.
Using mass flow = heat duty / (specific heat x temperature rise), the technology side needs about 9.19 kg/s, or 551 L/min, at its 10 K rise. The facility side needs about 11.72 kg/s, or 703 L/min, at its 8 K rise. These are energy-balance results. Vendor minimum flows and hydraulic calculations still control selection. Branch differential pressure, electrical capacity, structural acceptance, and the required maintenance case remain unknown. Hold construction pricing and propose an assessment.
For that assessment, use one local eight-hour daytime visit, with owner-provided drawings, trends, access, and an escort. The mechanical lead's 20 hours include eight on site and twelve for review and reporting. Two technicians each attend for eight hours. Controls and electrical reviews are remote, four hours each. The case uses two existing facility-water samples, one travel allowance, and no live-system manipulation. All amounts below are customer charges; hourly rates include labor burden, overhead, and profit.
| Assessment item | Quantity and rate | Charge |
|---|---|---|
| Mechanical lead | 20 hours x $165 | $3,300 |
| Two field technicians | 16 total hours x $115 | $1,840 |
| Controls review | 4 hours x $155 | $620 |
| Electrical review | 4 hours x $175 | $700 |
| Facility-water laboratory samples | 2 samples x $180 | $360 |
| Local travel allowance | 1 x $240 | $240 |
| Subtotal | All six charges | $7,060 |
| Assessment contingency | 10 percent x $7,060, applied once | $706 |
| Typical assessment price | Subtotal plus contingency, before tax | $7,766 |
Assessment deliverables and exclusions
The example price buys a marked layout and interface sketch, a record of available evidence, a preliminary duty reconciliation, a gap register, and a recommendation with the next study or measurement assigned. Deliver the two laboratory results with sample locations and the applicable comparison criteria. Include one remote owner review meeting within the lead's stated hours.
The example excludes construction, equipment purchases, design certification, structural engineering, permit fees, rental equipment, temporary cooling, intrusive testing, extended monitoring, outage execution, and tax. Additional visits or work outside the hours require a revised scope. Missing drawings do not become unlimited investigation under the same price.
If the owner instead requests an installed retrofit budget, obtain quotations and a developed quantity takeoff. Do not multiply the survey price by a guessed factor. In this example the narrow apparent thermal margin and unresolved interfaces are reasons to investigate further. They do not establish an equipment order or an installation allowance.
How do you choose bid, survey, hold, or pass?
Use the unresolved requirement to choose the next action. Spare thermal capacity cannot settle an unapproved shutdown or give a tenant authority over the shared plant. Assign each missing approval or measurement before releasing a construction bid.
Keep the account decision separate from the construction decision. A good customer may need an assessment before a bid. Record what would change your decision, who must provide it, and when you will review the file.
| Decision | Evidence available | Next action |
|---|---|---|
| Bid | Defined design, interfaces, acceptance criteria, access, and approved operating constraints | Price quantities, supplier quotations, execution, and commissioning |
| Survey | Confirmed sponsor and workload, with bounded technical unknowns | Agree assessment deliverables, access, price, and exclusions |
| Hold | Material capacity or permission question without a credible answer yet | Assign the missing evidence and review date |
| Pass | Required access or operating conditions cannot be obtained within your scope | Record the reason and conditions for reconsideration |
What to document
Keep the campus identifier, building and room, operator, sponsor, project stage, proposed platform, and target date together. Attach each drawing revision, source date, trend interval, sample identifier, and site observation. Give every capacity value its location, conditions, and status: reported, measured, calculated, or accepted by the responsible engineer.
A weak note says, 'Water available, quote eight racks.' A useful note says, 'Owner supplied a provisional plant worksheet for eight proposed 60 kW racks. Screened duty is 488 kW including the CDU pump input. Branch pressure and maintenance-state capacity remain unresolved. Construction price held pending engineer review and operator access approval.' The second note preserves both the calculation and its limits.
End the record with exclusions, open items, named owners, and a dated decision. Preserve the distinction between survey completion and construction acceptance. When a later revision changes rack count or heat split, update the calculation and reopen the affected decisions.
Common mistakes
- Treating a cooling yard, project announcement, or campus expansion as proof of an indoor retrofit requirement.
- Using total plant nameplate capacity while ignoring committed loads, operating temperatures, and the required unavailable-equipment case.
- Counting only heat captured by liquid and leaving residual air duty out of the plant and room review.
- Treating a liquid-to-air CDU as heat rejection outside the building.
- Copying another platform's coolant, flow, pressure, or temperature limits into the proposed scope.
- Pricing installation while leaving rack connections, controls integration, flushing, or commissioning assigned to nobody.
- Calling a survey successful without identifying the evidence needed for the next decision.
Field qualification checklist
Use this at the records review and authorized walkdown. Leave unresolved items open with an assigned person and due date. Checking an observation does not mean the proposed design has been accepted.
Want this checklist to run itself on every job — with photo proof and a signed record crews can hand the customer? That's FieldOS.
Standards and references
The six primary references linked in the relevant sections support the architecture, platform, assessment, power, operating-boundary, and commissioning discussion. DOE's guide is from 2024; the ASHRAE white paper is from 2021; the OCP document identifies revision 1.0. They provide background and workflow guidance. They do not approve this site's design.
For a November 2026 qualification, obtain the selected equipment's current requirements and the engineer's project basis. Confirm applicable code editions and permits with the authority having jurisdiction. This guide sets no universal pressure-test value, coolant specification, temperature class, redundancy claim, or construction price. Recheck the linked live manufacturer documentation when the platform or scope changes.
Units and terms
- CDU
- Coolant distribution unit; identify its rejection method and both connection boundaries.
- FWS
- Facility water system; the building fluid circuit serving the liquid-to-liquid CDU in this example.
- TCS
- Technology cooling system; the coolant circuit serving the IT equipment.
- kW
- Kilowatts; state whether the value describes electrical input or thermal duty.
- K
- Kelvin; a temperature difference of 1 K equals a difference of 1 C.
- L/min
- Liters per minute; volumetric flow, separate from the available differential pressure.
Finding retrofit accounts in your service area
Build the territory list around campuses your team can actually survey and support. Define travel limits, the facility types you understand, and the access and operating conditions your crew can handle. Use public records, operator information, and dated exterior observations to identify sites. Confirm the operator and project sponsor before committing engineering time.
PorchRocket Asset Search offers custom searches and monitoring of assets visible from above. Start with its cooling-tower search and describe the visible cooling equipment and campuses you want reviewed. Agree on geography, evidence dates and unresolved classifications before using the results for qualification calls.
Carry the resulting campus record into the qualification worksheet. Leave interior cooling, capacity, condition, and buying intent unconfirmed until the facility team supplies evidence. The useful handoff is an identified site and a specific technical conversation to pursue.
Methodology
Counts, prices, work rates, schedules and outcomes in typical cases are inputs to the Anvilfield research model. Calculations use the stated scope, formulas, cost inclusions and exclusions. Cited public records and technical documents support their attributed facts.
FAQ
Can an existing air-cooled data center be retrofitted for liquid cooling?
Yes, if the selected equipment, heat-rejection path, power, structure, access, and operating constraints can be made compatible. Confirm both liquid and air duties. Qualification determines which records and studies are needed before an engineer can approve the retrofit.
What is the first question to ask a liquid-cooling retrofit prospect?
Ask which IT platform and concurrent rack load are proposed, where they will go, and who can authorize the facility review. Those answers establish whether you can scope an assessment and identify the people responsible for shared infrastructure.
Does liquid cooling eliminate the existing air-cooling load?
No. Some platforms retain air-cooled components, and supporting equipment can add room heat. Obtain the actual platform heat split and include the residual duty in the room and plant review rather than presuming a standard percentage.
Can a liquid-to-air CDU avoid a facility-water connection?
Yes, at that CDU, but the room cooling must remove the heat it rejects. Check the available air-cooling capacity and the complete path outdoors before selecting that approach for a retrofit.
Can aerial images identify a liquid-cooling retrofit opportunity?
They can identify a campus to investigate, but they cannot establish interior cooling scope or a purchase requirement. Keep the evidence date and visible observation, then verify the operator, workload, and proposed work through records and an authorized site review.
What does a liquid-cooling retrofit survey cost?
The typical assessment here totals $7,766 before tax under its stated labor, sampling, travel, and contingency inputs. Build your own assessment price from deliverables, access, staffing, measurements, and exclusions; obtain a developed scope before pricing installation.
Is spare chiller capacity enough to qualify the project?
No. You also need the required operating temperature, branch flow and pressure, residual air duty, electrical capacity, physical fit, and approved operating conditions. Confirm usable duty in the required maintenance case rather than relying on installed capacity.
When should a contractor hold the construction bid?
Hold it when a material interface, capacity limit, acceptance criterion, or operating permission remains unresolved. Name the missing evidence and the person responsible for it. A separately scoped assessment may still be the appropriate next job.