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Modular data centres for small sites

By G2MAX · Updated 1 November 2026

A modular data centre can make a small first phase easier to define and repeat. It does not remove the need for a suitable site, a firm power supply or a complete cooling and operating plan. Treat the module as one part of the facility. Start by drawing the site boundary and the connections needed to make the first module useful.

Choose the right unit of growth

Define the opening IT load, the expected rack mix and the next likely increase in demand. A module might be a room assembly, a prefabricated enclosure or a repeatable group of racks and supporting equipment. State which meaning applies in the brief so the owner and suppliers are pricing and planning the same scope.

Choose a growth increment that fits available power and actual demand. For example, twenty racks planned at 8 kW each represent 160 kW of IT load before facility overhead. That arithmetic does not establish cooling airflow or electrical diversity, but it gives the team a clear starting point. Check whether future racks will have the same density; a few high-density racks can change the cooling arrangement substantially.

Survey the site and delivery route

Confirm boundaries, levels, drainage, ground bearing conditions and buried services. If the module will arrive assembled, check transport dimensions, turning radii, lifting positions and crane access. A module that fits the plot may still be impossible to deliver through the approach road or lift past nearby obstructions. Resolve the route before fixing the enclosure size.

Allow working space around the installed module. Doors, filters, electrical panels and cooling equipment need clear access. Keep escape routes and emergency access usable when the next module is added. If the module sits beside an existing building, check the effects on its drainage, fire access, outdoor plant and future maintenance routes. Small sites have little room to absorb late changes.

Define every utility connection

List the incoming electrical supply, earthing, communications, water where needed, drainage and any fuel system. State the exact point where each supplier's responsibility begins and ends. Include the controls and alarms required to make the module visible to the site operator. Factory installation does not guarantee that external interfaces have been designed or supplied.

Confirm voltage, fault levels and protection coordination before selecting incoming equipment. Match the opening load to the firm connection rather than the capacity requested for a later phase. If temporary generation is proposed, describe its duration, operating duty and connection arrangement. A temporary label does not remove the need for safe switching, fuel access, heat rejection and an operating procedure.

Keep cooling and power expandable

Use repeatable boundaries where practical: spare distribution ways, accessible cable routes and identified pipe connection points. Decide which plant serves one module and which plant is shared across the site. Shared equipment may reduce duplication, but it can also introduce common failures and make later expansion more disruptive.

Test the redundancy arithmetic at opening load and after each addition. A spare cooling unit in the first phase may become a duty unit in the second. The same applies to generators, UPS modules and transformers. Make these changes explicit in a capacity table so the owner does not assume the original resilience arrangement continues automatically as racks are added.

Review the complete footprint

The enclosure is only part of the required area. Include heat rejection, generators, fuel, electrical rooms or skids, maintenance clearances, deliveries and spare capacity. Check noise and exhaust paths relative to neighbours and outdoor air intakes. Equipment squeezed into the remaining space can create hot-air recirculation or make basic maintenance unsafe.

Inside the module, check rack clearances, cable management and the route for replacing heavy equipment. Consider who will service the installation and how quickly they can reach it. Standardised equipment and a manageable spare-parts list can matter more to a remote small site than a slightly smaller footprint. Keep the design understandable to the team that will operate it.

Test the installed facility, not only the module

Factory tests can establish assembly quality and functional behaviour within the supplier's scope. Site tests must also prove the external interfaces, earthing, protection, alarms, cooling performance and backup sequence. Agree which results carry over from factory testing and which must be repeated after transport and connection.

Handover should include drawings that match the final installation, settings, test records, equipment information and maintenance tasks. Record the permitted expansion envelope and the conditions for adding the next module. A repeatable design remains useful only while later additions preserve access, power capacity and the tested operating sequences of the live site.

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