Two constraints now shape every thermal design in Johor
Johor has become one of the fastest-growing data centre markets in Southeast Asia. But two conditions bound what any cooling design can realistically achieve there:
- A tropical climate. Ambient design temperatures above 30 °C year-round with typical relative humidity of 80%+ compress the hours available for air-side free cooling.
- A state-level water restriction. In November 2025, Johor signalled that data centre operators should hold off water-based cooling expansion for at least 18 months — effectively to mid-2027.
What the PUE gap actually looks like
In tropical conditions the two approaches separate clearly. The figures below are industry reference ranges for the Johor / Malaysia market rather than measured results from a specific facility.
(tropical baseline)
(target band)
(best-in-class)
The gap is structural, not an equipment-efficiency problem. Air-side systems in hot, humid climates spend more energy rejecting heat to ambient. Liquid cooling moves heat through a closed loop at a higher temperature differential, which is why the achievable band is materially lower.
Why water policy changes the selection
| Source | Date | Relevance to design |
|---|---|---|
| South China Morning Post | 18 Nov 2025 | Operators told to postpone water-based cooling expansion for at least 18 months |
| New Straits Times | 26 Nov 2025 | Tier 1 / Tier 2 approvals tightened; up to 50 million litres per day consumption cited |
| Mordor Intelligence | 05 Mar 2026 | Water cap drives adoption of dry coolers or closed-loop liquid systems, at 25–35% higher installation cost |
WUE is now an approval consideration. A design that depends on large volumes of make-up water carries schedule risk that a closed-loop design does not. Where a water-based design cannot proceed, conversion pathways to closed-loop or dry-cooler heat rejection should be evaluated early in the programme.
CDU selection: the dimensions that drive the decision
| Dimension | Typical options | Selection question |
|---|---|---|
| Capacity | 20 kW – 1 MW+ | Sized to rack density × redundancy factor |
| Architecture | In-row / in-rack / row-level CDU | Greenfield layout versus retrofit constraints |
| Coolant | Water-glycol (e.g. PG25) / treated water | Loop temperature and freeze risk at site |
| Redundancy | N+1 pumps, dual power feed | Target SLA tier and maintenance window |
| Controls | Modbus / BACnet, BMS integration | Compatibility with existing DCIM |
| Filtration | Micron rating of filter loop | Matched to cold plate channel width |
Cold plate
- Thermal coverage — per-socket TDP envelope for the AI/GPU class deployed, to 120 kW rack scale.
- Material and finish — copper, or copper with nickel plating for coolant compatibility.
- Hydraulics — flow rate and pressure-drop budget against the CDU pump curve.
- Connection — drip-free quick disconnects; blind-mate options for service access.
BIM coordination happens before procurement
Cooling infrastructure is decided at design stage. Pipe routing conflicts identified after MEP coordination sign-off translate directly into site rework, so we supply coordinated model content — Revit and Navisworks families for CDU units, manifolds and cold plate assemblies — to bring the cooling scope into the coordination cycle early.
Supply: arranged to your project, not fixed by us
DHC Resources supplies from a Hong Kong hub, with delivery into Johor arranged to the project's own schedule and requirement. Transport mode — sea, air or multimodal — is selected per project. Indicative lead time for CDU and cold plate supply into Johor Bahru is 6–8 weeks DAP, against 18–24 weeks currently observed for comparable international OEM supply.
Request the full technical brief
The complete 5-page guide includes the full CDU and cold plate selection framework, the BIM delivery scope and lead-time comparison.
Download the brief (PDF) Discuss your specificationCDU · Cold Plate · Manifolds · Rack Power — supplied to project specification from our Hong Kong hub.