With the explosive growth of AI large models and high‑performance computing, the power consumption of a single AI chip has soared from hundreds of watts to over a kilowatt — and data centre thermal density continues to climb. In this context, liquid cooling is rapidly shifting from a high‑end option to a mandatory choice for high‑compute deployments.
Currently, single‑phase cold‑plate liquid cooling holds more than 80% of the market, thanks to its deployment flexibility and compatibility with existing data centres. It has become the mainstream route for large‑scale liquid‑cooling adoption.
⚙️ Industry pain points
Despite rapid market growth, the liquid‑cooling industry faces non‑uniform standards, lack of selection guidelines, missing unified testing and certification for key components, and insufficient supply‑chain coordination — all of which directly threaten long‑term reliability.
On June 24, 2026, Intel held the “Cold‑Plate Coolant Qualification & Ecosystem Launch” in Shanghai, officially releasing the results of its single‑phase cold‑plate liquid‑cooling working‑fluid qualification. Products from Castrol and Envicool successfully passed Intel’s rigorous validation.
This launch was more than a product certification — it marked a key step by Intel, as a neutral industry player, to build a standardised working‑fluid certification system and cultivate a local liquid‑cooling supply chain, setting a quality benchmark for the entire ecosystem.
🎙️ David Zhou · Intel China Data Center Group
“The working fluid is the most critical factor in the entire liquid‑cooling loop — it’s like the blood of the system. Its performance and quality determine the upper limit of heat dissipation, and its material compatibility with pipes and cold plates directly affects leakage, scaling, and corrosion risks. It’s the key to long‑term reliable operation.”
Yet during the industry’s rapid growth phase, there has been no neutral, credible, and comprehensive qualification system. Most customer selection relies on vendor self‑certification, lacking authoritative cross‑comparison.
David Zhou noted that until recently, only two North American manufacturers had passed Intel’s working‑fluid qualification — both without local production bases, leading to lead times of over 6 weeks and high costs. Few major Chinese CSPs adopted them. This strong local demand for near‑source supply, rapid response, and cost control drove Intel China to launch the “Liquid Cooling Innovation Acceleration Plan” and lead local qualification efforts.
Rigorous validation · real‑world loop
As a core contributor to the OCP single‑phase cold‑plate liquid‑cooling specification, Intel combined its internal Liquid Cooling Design Guide (LCDG) with OCP standards to build a stringent, real‑scene validation system. Unlike traditional single‑sample lab tests, this validation used a full secondary‑side loop — replicating cold plates, manifolds, pipes, seals, and other real‑world components — with harsh boundary conditions: 1.5 m/s inlet flow, 65°C outlet temperature, and high‑temperature accelerated ageing.
- Corrosion inhibitor retention > 80% of initial value
- Cold‑plate thermal performance deviation < 5%
- Metal corrosion rate < 0.22 thousandths of an inch per year
The entire test cycle lasted over 7 months, with 30 sampling rounds and more than 9,000 data points. The assessment extended from traditional chemical composition analysis to system‑level metrics including metal corrosion rates, non‑metal mechanical property changes, and cold‑plate thermal stability.
To ensure neutrality, all samples were tested in double‑blind mode by third‑party accredited labs, with final compliance judged by Intel.
📐 A reusable validation methodology
“We’re not just doing product conformance testing — we’re giving the industry a reusable validation methodology,” said Zhou. The standard is not region‑specific; all qualified products are published on Intel’s global IDC technical documentation platform, with the same validity as certifications from North American and European labs, available for reference by customers worldwide.
Castrol PG 25 C · from formulation to full‑cycle
Among the qualified products, Castrol PG 25 C — a propylene‑glycol‑based coolant — stood out with excellent overall performance, becoming the first internationally branded, locally supplied product to receive Intel certification.
The project lasted 14 months from initiation in April 2025 to the June 2026 release. Castrol partnered with local partner Yixintong to build a complete test loop, using Intel’s TTV thermal test vehicle to simulate real chip heat loads, covering the full journey from lab formulation to system‑level validation.
🧪 Fan Qinghua · Castrol Thermal Management
“PG 25 is not an arbitrary concentration — it’s the optimal balance validated by long‑term industry practice. Deionised water has excellent thermal conductivity but is prone to bacterial growth and metal corrosion. Higher propylene‑glycol concentration improves inhibition but reduces thermal efficiency. After extensive testing, the 25% propylene‑glycol + 75% deionised‑water ratio provides the best trade‑off between thermal efficiency, antibacterial performance, and corrosion protection — a global industry consensus.”
Test results showed that Castrol PG 25 C significantly outperformed industry benchmarks:
- During 180‑day accelerated ageing, the fluid remained clear with no precipitation or discolouration.
- Metal corrosion rates for copper, solder, brass, steel, and cast iron were all superior to ASTM D1384 requirements.
- Non‑metal compatibility — EPDM seals retained >95% of hardness, mass, volume, and tensile properties, effectively avoiding leakage risks from seal deformation or ionic precipitation over long‑term immersion.
💬 Qiu Yuanyuan · Castrol Greater China Business Director
“In a high‑density data centre, servers account for 60‑70% of total investment, with CPUs and GPUs as the core value. Coolant may seem like a small cost item, but it’s a potential single point of failure — a leak could directly damage millions of dollars of IT equipment. Scaling or bacterial growth can reduce heat dissipation and ultimately throttle compute output.”
He added that Castrol proactively collected mainstream non‑metal pipe and seal products from the market to complete compatibility tests in advance, helping customers avoid hidden long‑term risks. “We set the test temperature at 65°C — about 20°C higher than normal server operation — essentially an accelerated ageing test to validate stability over the full lifecycle.”
Beyond product performance, Castrol has pioneered the concept of end‑to‑end integrated services, moving beyond the traditional “selling fluids” model. Song Ting, Global Marketing Director of Castrol Thermal Management, said in an interview: “With 127 years of fluid technology expertise, we are transforming from a lubricant brand into a thermal‑management solution provider.”
- Installation phase — on‑site fluid testing and filling
- Operation phase — periodic lab monitoring and online fault handling
- End‑of‑life — global fluid recovery and closed‑loop management
Local production bases also enable Castrol to significantly shorten delivery cycles, reduce logistics costs, and precisely match local customers’ supply‑chain needs.
Beyond fluid · Intel’s long‑term liquid‑cooling ecosystem
This working‑fluid qualification is only one milestone in Intel’s broader liquid‑cooling strategy. David Zhou revealed that the Liquid Cooling Innovation Acceleration Plan will extend to cold plates, quick‑disconnect couplings, CDUs, manifolds, and other key components, progressively standardising the entire chain.
🔄 Cold‑plate vs immersion · pragmatic view
On the technology‑route debate, Zhou noted that single‑phase cold‑plate currently holds >80% market share and is the mainstream scalable solution. Immersion cooling has advantages for higher compute density and waste‑heat recovery, and its share will gradually rise — but the pace depends on industry collaboration, especially retrofitting existing data centres with weight and operational challenges.
Meanwhile, environmental concerns around low‑boiling‑point fluorinated fluids have made single‑phase immersion a more attractive direction. Intel has already developed an environmentally friendly synthetic‑oil‑based single‑phase immersion technology.
Castrol is also pursuing a dual‑track strategy. Qiu Yuanyuan told Semiconductor Industry Observer that in cold‑plate cooling, Castrol PG 25 C has already achieved large‑scale deployment. On the immersion side, products like DC 15 and DC 20 are undergoing POC trials in data centres in the UK, Australia, and China, and have received Intel’s recommendation for single‑phase immersion ecosystems. “Cold‑plate is the technology of today; immersion is the future waiting to bloom. We will walk on both legs, iterating with industry demand.”
Industry impact · from fragmented to systemised
From a broader perspective, Intel’s qualification initiative does more than fill a product‑standard gap — it is pushing the local liquid‑cooling supply chain from scattered manufacturing toward systematic certification, giving domestic vendors credible global backing.
- For customers, uniform certification reduces selection costs and trial‑and‑error risks, providing a clear quality reference.
- For the industry, a neutral third‑party verification system will gradually end the fragmentation of working‑fluid standards, driving the sector from rapid expansion to high‑quality, regulated development.