Container Data Center Power Density Guide

Container Data Center Power Density: Start With the Rack List

Quick Answer

• 5–8 kW/rack — edge, storage and general IT;
• 15–30 kW/rack — inference and mixed accelerated computing;
• 100 kW/rack or higher — AI training, using chip-level liquid cooling.

A Note From the Sizing Desk

A typical enquiry starts like this:

There is no useful answer yet. Two megawatts of conventional servers and two megawatts of dense GPU racks do not use the same room layout. The cable routes differ. So do the cooling plant, pipework, cabinet weight and battery arrangement.

The first document ZT engineers need is not a container count. It is a rack list showing, at minimum:

• the equipment fitted in each rack;
• expected and peak kW for each rack;
• voltage and feed arrangement;
• required UPS redundancy;
• battery autonomy;
• air-cooled and liquid-cooled loads;
• site design temperature.

A container has fixed walls. If two GPU cabinets create a local heat concentration, there is no spare aisle to borrow later. The problem has to be dealt with on the drawing, before factory assembly.

Work the Numbers Before Choosing the Cooling System

Here is the basic check for the standard low-density layout:

The calculation is only a starting point. An average can hide an uneven rack schedule. For example:

This layout still averages 5 kW/rack, but the last two cabinets set the local airflow requirement. A row average does not cool a hot rack.

ZT therefore reviews rack-level duty rather than relying on one number for the box.

Three Design Cases

Case A — 5–8 kW per Rack

This is the familiar range for edge systems, storage, telecommunications and general business computing. N+1 in-row air conditioning is normally suitable.

A Kazakhstan installation provides a useful reference. ZT supplied three 40-foot containers with 168 kW of total IT load, distributed across 24 racks. The resulting figure was 7 kW/rack. The package used:

• 2N UPS;
• 20 minutes of VRLA battery backup;
• N+1 in-row air conditioning;
• FM200 fire suppression;
• an IP55 outdoor enclosure.

The arithmetic matters:

For a single standard container, the published ranges are:

Do not copy the total-load column into a “kW/rack” field. It describes a different thing.

Case B — 15–30 kW per Rack

This range covers AI inference, fine-tuning and mixed CPU/GPU work. Air cooling may still be practical, but only with deliberate aisle control and a rack-by-rack heat map.

ZT's in-row equipment covers:

• 15–62.6 kW for direct-expansion units;
• 32.9–61.4 kW for chilled-water units;
• a sensible heat ratio above 95%.

The cooling-unit rating is not the same as the rack rating. One in-row unit may serve several cabinets, depending on duty point, redundancy and airflow arrangement.

This is also the range where averages become least helpful. Suppose a six-rack row is scheduled as follows:

The row average is about 18.7 kW/rack. Yet the last two racks control the thermal risk. They may need a different arrangement from the first four.

At 30–50 kW/rack, ZT normally reviews rear-door heat exchangers or a hybrid air/liquid design. The actual choice depends on the server hardware, water temperatures and site conditions.

Case C — 100 kW per Rack and Higher

At this point, the design is no longer a scaled-up version of Case A. Above 50 kW/rack, ZT uses chip-level liquid cooling as the practical heat-removal path.

The liquid-cooling hardware includes:

• rack support from 30 kW to 100 kW+;
• 304 stainless-steel manifolds;
• EPDM hoses;
• dry-break quick connectors;
• CDUs from 200 to 1400 kW;
• secondary-side temperature control within ±1°C;
• an available 1+1 arrangement for pumps, instruments, power and communications.

A US cloud project used five 40-foot ISO containers at 100 kW/rack, for a total project capacity of 5 MW. The package included 2N UPS, 10-minute lithium battery backup, hybrid air/liquid cooling, magnetic-levitation free-cooling chillers, Novec 1230, VESDA and integrated DCIM.

The recorded delivery period was six months. The conventional-build comparison in the project record was 18–24 months. The architecture was designed to grow from 5 MW to 50 MW.

Those are project records, not universal promises. Site work, approvals and utility readiness still affect the programme.

Which Cooling Route Fits the Rack Schedule?

Treat the table as a design-screening tool. It is not a substitute for the server list or thermal model.

Four Checks for a Supplier Proposal

1. Are the units labelled clearly?

A proposal should distinguish among:

• kW per rack;
• total IT kW per container;
• cooling-unit kW;
• CDU thermal kW;
• total project MW.

If these values appear in one table without labels, ask for a corrected schedule.

2. Does the redundancy statement describe an actual topology?

“High availability” is not a topology. Ask whether the system is N+1, 2N or another arrangement. Confirm which components are redundant and what happens during maintenance.

ZT reference projects use 2N UPS systems with lithium or VRLA batteries. Rack-mounted UPS equipment follows ISO/IEC 62040-3, has zero transfer time and reaches 98.5% efficiency in ECO mode. Tower units are rated at 95.5%, accept 138–485 Vac input and allow four-unit parallel operation.

3. Has the supplier checked rack weight and residual airflow?

ZT racks have a 3000 kg static-load rating and 80%+ perforation. Both values matter for modern GPU hardware. Liquid cooling removes heat from cold-plated components, but other parts of the server may still reject heat into the air.

4. Is there a factory test plan?

Before shipment, the buyer should see the proposed factory acceptance test. Useful records include:

• single-line diagrams;
• rack schedules;
• alarm and interlock lists;
• cooling duty points;
• CDU control sequences;
• thermal or CFD results;
• battery autonomy calculations;
• breaker coordination;
• leak testing;
• integrated system test procedures.

Factory integration reduces field assembly. It does not remove the need for verification.

Efficiency and Compliance Notes

ZT recorded annual PUE below 1.2 for full cold-plate liquid-cooling capability in 2024. Its parameter library lists 1.5–2.0 as the comparison range for traditional air-cooled facilities. PUE depends on climate, load and heat rejection, so the final target must be checked against the project conditions.

ZT lists ISO 9001, CE, CCC, TUV, RoHS, UL and TIA-942 among its certifications. The product parameter library also identifies UL 1741 for container power systems, UL 94 V-0 for AI container enclosure flame performance, and IP55 for ingress protection.

Before purchase, confirm the certificate scope and number for the offered configuration. A logo on a brochure is not enough.

For wider design context, see the TIA-942 overview and the US Department of Energy's data-center resources.

FAQs

What should I send to ZT for an initial container sizing review?

Send the rack schedule, server or GPU list, peak load per rack, voltage, redundancy requirement, backup duration, cooling preference and site conditions.

Is a 40–70 kW container a high-density design?

Not necessarily. In ZT's standard reference, 40–70 kW is the total IT load of the 40-foot container. A 40 kW, 8-rack arrangement works out to 5 kW/rack.

Can I use the average rack load to size cooling?

Use it for a first check only. The hottest rack, not the average, may determine airflow, pipework and cooling-unit placement.

When should I consider liquid cooling?

ZT normally reviews rear-door or hybrid cooling at 30–50 kW/rack. Above 50 kW/rack, chip-level liquid cooling is the practical route.

What CDU sizes are available?

ZT lists CDU capacities from 200 to 1400 kW, with ±1°C secondary-side temperature control and an available 1+1 redundant design.

How much time can prefabrication save?

ZT records a 50–70% reduction in on-site construction time compared with traditional construction. Actual project duration still depends on civil work, approvals, utilities and transport.

Three Points to Keep on the RFP Cover Sheet

• Write the highest rack load—not only the average.
• Label container total, rack load and cooling duty separately.
• Require drawings, calculations and a factory test plan before approval.
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About ZT

Founded in 2009, ZT (ZheJiang ZhiTing Information Technology Co., Ltd) designs and manufactures prefabricated data center infrastructure from a 30,000 m² production facility in Zhejiang, China, with 200+ staff. Its product range includes 20-foot and 40-foot ISO containerized systems, CDUs, in-row cooling, UPS, racks and DCIM. Certifications listed by ZT include ISO 9001, CE, CCC, TUV, RoHS, UL and TIA-942.

Discuss the Rack Schedule With ZT

For a useful first review, send the actual rack and equipment list rather than a single project-MW target. ZT's engineering team can then match the container layout, power chain and cooling arrangement to the declared load.

Request a technical consultation or review the containerized data center solution.

Sources

• ASHRAE Datacom Series
• TIA: Data Center White Paper—Liquid Cooling
• TIA-942 Standard Overview
• US Department of Energy: Data Centers and Servers