THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF REGULATION (EU) 596/2014 AS IT FORMS PART OF UK DOMESTIC LAW BY VIRTUE OF THE EUROPEAN UNION (WITHDRAWAL) ACT 2018.

15 September 2026

Haydale plc

(“Haydale” or the “Company”)

Commercialisation update –

SETTF achieves water-equivalent thermal performance in data-centre cooling application

SETTF increases the thermal conductivity of inhibited glycol coolant by approximately 28 per cent., restoring it to the level of pure water

Potential to increase thermal headroom in existing data-centre cooling infrastructure, supporting cooler processors, lower cooling energy or greater compute capacity

Successful live-silicon testing, commercial agreements signed and advanced discussions with data-centre operators covering approximately 200 MW

Haydale plc (AIM: HAYD), the advanced materials and clean-technology group, announces successful application testing of its patented Super-Efficient Thermal Transfer Fluid ("SETTF"), together with the signing of agreements with Liquitherm Technologies Group Limited, trading as DC Cooling Solutions ("Liquitherm"), and Levidian Nanosystems Limited ("Levidian"), establishing the supply chain and route to market. The Company and its commercial partners are in advanced discussions with data-centre operators representing approximately 200 MW of capacity, with first installations targeted within twelve months.

SETTF is designed to remove the thermal-performance penalty caused by adding glycol to data-centre cooling systems. In testing, SETTF achieved a thermal conductivity approximately 28 per cent. above that of the baseline inhibited glycol coolant, restoring it to the level of pure water while retaining the freeze, corrosion and fouling protection for which glycol is required. For data-centre operators, this has the potential to provide additional cooling headroom from existing infrastructure, which may be used to run processors cooler, reduce cooling energy and flow requirements, or support greater compute capacity.

SETTF represents the second proprietary product platform to emerge from Haydale’s product-led strategy established following the December 2024 restructuring programme, after JustHeat®, the Group’s graphene-enabled electric underfloor heating technology. SETTF has now progressed from development into an application-tested technology with a defined route towards commercial deployment.

Key highlights:

The glycol penalty

Glycol coolants are widely used in data-centre cooling, building climate control, industrial process cooling and refrigeration. Adding glycol provides essential freeze protection, but at the cost of reduced thermal performance.

In cold-plate testing undertaken by NVIDIA engineers and published by the American Society of Mechanical Engineers, a 25 per cent. ethylene glycol coolant exhibited 18 per cent. higher thermal resistance than treated water at 2 litres per minute, while a 55 per cent. blend exhibited 36 per cent. higher thermal resistance [1].

In Haydale's testing, SETTF increased thermal conductivity by approximately 28 per cent. against the baseline fully inhibited 22 per cent. glycol fluid, reaching 0.625 W/mK at 35 °C, compared with 0.6215 W/mK for pure water at the same temperature [2]. The SETTF formulation, based on Liquitherm's DTX® glycol technology, retained the coolant's freeze, corrosion, scaling and fouling protection without increasing viscosity. W/m K (Watts per metre-Kelvin) is the standard international unit used to measure thermal conductivity.

SETTF has been developed as an ultra-low-dose performance additive to the inhibited coolant already specified and used by an operator, rather than as a replacement base fluid. The objective is therefore not to replace the protective characteristics of glycol, but to recover the thermal performance otherwise sacrificed by its use.

Potential value to data-centre operators

The thermal penalty associated with glycol can also be expressed as operating temperature. In the NVIDIA testing at 1,000 W, a 25 per cent. ethylene glycol coolant operated approximately 3 °C hotter than treated water [1].

The Directors believe that restoring coolant conductivity towards that of water therefore has the potential to create additional thermal headroom within an equivalent cooling loop. Depending on how a facility is operated, this may be taken as lower coolant flow, lower processor temperature, reduced cooling energy or greater compute density.

The potential economic value of such temperature improvements is recognised by the industry. Singapore's Infocom Media Development Authority estimates cooling-energy savings of approximately 2 to 5 per cent. for every 1 °C increase in operating temperature [3], while NVIDIA has stated that operating a cooling loop at 45 °C rather than 35 °C can free sufficient power to support up to 10 per cent. more NVL72 racks [4].

Where electrical power is the limiting factor on data-centre capacity, recovered thermal headroom can therefore have significant economic value. Based on the Company's modelling, the Directors estimate that an additional degree of usable operating headroom could represent approximately US$3 million to US$4 million per annum of gross capacity value for a 50 MW facility.

On the same illustrative basis, each additional degree of usable operating headroom across the approximately 200 MW of data-centre capacity currently under discussion could represent approximately US$12 million to US$16 million per annum of gross operator capacity value.

These figures illustrate potential operator economics rather than revenues attributable to Haydale and will vary materially according to facility design, climate, power availability, operating conditions and the extent to which improved thermal performance can be converted into usable capacity.

The value of this thermal headroom is increasing as AI infrastructure becomes more thermally demanding. Rack densities have risen to more than 100 kW for current AI installations [3], while individual processors can now draw approximately 1,400 W [5]. At the same time, operators are seeking to run cooling loops at higher temperatures to reduce reliance on energy-intensive mechanical chilling; NVIDIA's Vera Rubin reference design, for example, specifies coolant entering at 45°C [6]. The Directors believe these trends increase the potential relevance of SETTF as its thermal conductivity improves and viscosity reduces as temperature increases.

Technology and application testing

Graphene's high surface area enables meaningful thermal effects at very low concentrations. Historically, however, the use of nanoparticles in heat-transfer fluids has been constrained by dispersion, stability and viscosity, with higher particle concentrations contributing to settling, fouling and thickening.

Haydale's proprietary HDPlas® process functionalises the outer atomic layers of graphene to enable dispersion within the fluid while retaining the underlying material's thermal properties.

SETTF uses Levidian G3 graphene functionalised through Haydale's HDPlas® process and is designed to be dosed into the coolant already used by an operator rather than replacing the underlying base fluid.

At below 0.05 per cent. by weight, SETTF achieves its measured thermal effect at an exceptionally low concentration. The Directors believe this low loading is important both to maintaining the hydraulic characteristics of the underlying coolant and to the scalability and economics of commercial deployment.

The technology has been tested directly against pure water using an independently designed rig operating a live 250 W processor. Across triplicate tests, coolant flow, pump power and processor temperature were equivalent to those recorded using pure water, with no settling, fouling or thickening observed.

The Directors believe these results demonstrate that SETTF can provide enhanced thermal performance while retaining the hydraulic characteristics required for direct-to-chip cooling applications.

Qualification and first deployments

Commercial coolants must demonstrate more than thermal performance, including corrosion resistance, long-term stability, materials compatibility, particulate and electrical conductivity limits, and compliance with applicable OEM and industry requirements [7].

Earlier generations of Haydale's thermal-fluid technology have already passed ASTM D1384 and D8040 corrosion testing across all six standard metals [8].

The next stage of commercialisation is focused on Liquitherm-led formulation and OEM qualification, higher-load system testing and first operator deployments.

The Company and its commercial partners are in advanced discussions with data-centre operators representing approximately 200 MW of capacity, equating to approximately 200,000 litres of treated coolant. Installation is targeted within twelve months. There can be no certainty that these discussions will result in orders.

Commercialisation agreements

Haydale has signed agreements with Liquitherm and Levidian, establishing the supply chain and route to market for SETTF. The parties intend to take SETTF to market jointly, drawing on DC Cooling Solutions' data-centre customer base and their respective industry channels, with joint manufacturing, marketing and distribution.

Given the scale and pace of development within AI cooling, Haydale intends to establish a dedicated commercialisation venture to hold the SETTF business. The venture is intended to be funded by dedicated external capital raised directly into it, accelerating qualification, market adoption and international deployment.

Haydale intends to retain ownership of its underlying SETTF and HDPlas® intellectual property, which would be made available to the venture, continue to supply the Haydale-functionalised graphene, and retain a controlling equity interest.

DC Cooling Solutions (www.dccoolingsolutions.com), part of the Liquitherm Technologies Group, specialises in cooling fluids and associated technical services for data-centre primary-loop, direct-to-chip and immersion cooling systems, including commissioning, fluid monitoring and maintenance. Liquitherm is a leading global specialist in the formulation and manufacture of heat transfer fluids, glycol formulations, corrosion inhibitors and water treatment chemicals, with operations in the United Kingdom, the United States and Europe. Under its agreements with Haydale, Liquitherm will supply the inhibitor and glycol package for SETTF and manage its qualification with OEMs and standards bodies.

Levidian (www.levidian.com) is an advanced materials technology company and the developer of the proprietary LOOP® technology, which produces high-quality graphene and hydrogen from methane. Levidian's G3 graphene is the base material functionalised by Haydale for use in SETTF. Levidian will supply the graphene required for SETTF and, as volumes scale, its modular LOOP technology provides the potential to establish localised graphene production close to key end markets. Levidian already has an international presence, including in the UAE and Malaysia, providing potential routes to support future regional manufacture and supply of SETTF as the opportunity develops.

Market opportunity

The Company's analysis indicates that the global installed base of glycol-containing closed-loop cooling systems is measured in billions of litres, across data centres, building climate control, industrial process cooling and refrigeration. Data centres are the Company's initial focus.

JLL forecasts approximately 97 GW of new data-centre capacity between 2026 and 2030, with approximately 80 per cent. of new facilities expected to adopt liquid cooling [9]. At approximately 1,000 litres of coolant per MW of IT load, the Company estimates a first-fill requirement of approximately 15 million litres each year and more than 75 million litres in service by 2030.

Publicly available pricing provides an illustrative benchmark of approximately US$8 to US$12 per litre of treated coolant, derived from the stated two-to-three-times premium of an enhanced heat-transfer fluid over traditional glycol [10] and currently published data-centre glycol pricing [11]. On that basis, the approximately 200 MW of capacity currently under discussion, representing approximately 200,000 litres of coolant, would equate to approximately US$1.6 million to US$2.4 million of gross end-market product value.

At the current SETTF formulation, existing functionalisation capacity at Ammanford is sufficient to support approximately 2 GW of data-centre capacity and, on the same illustrative basis, US$16 million to US$24 million of annual gross end-market product value at full utilisation, without requiring an increase in existing functionalisation capacity.

These figures illustrate the potential commercial scale of the opportunity and do not represent forecasts of Haydale revenue. Actual pricing and the proportion of end-market revenues attributable to Haydale will depend upon customer specifications, qualification and final commercial arrangements with its partners. Existing data-centre infrastructure provides a further retrofit market: approximately 103 GW of capacity was in service in 2025, and JLL expects cooling and power upgrades to be the most common retrofits [9].

Commercialisation of SETTF is intended to reflect the value of the patented formulation, the volume of coolant treated and the performance delivered, rather than the commodity value of the underlying graphene. The model is therefore capital efficient and scalable, and against the current scale of the Group, the Directors believe that even modest penetration of this market would be material.

Intellectual property

Haydale's UK patent covering its thermal-fluid composition was granted in February 2026 and runs to 2042 [12]. The patent protects the fluid composition together with associated use and system claims, including claims specifically covering a base fluid comprising water and glycol with a corrosion inhibitor.

Corresponding patent applications are progressing in Europe, North America and Asia. The technology is further supported by Haydale's wider portfolio of plasma-functionalisation and reactor patents, together with proprietary formulation and manufacturing know-how retained as trade secrets.

Simon Turek, CEO of Haydale, commented:

"The simple result is that SETTF increased the thermal conductivity of a glycol coolant by approximately 28 per cent., restoring it to the level of pure water. In practical terms, that means a data centre could potentially get more cooling performance from the same infrastructure, without giving up the freeze and corrosion protection for which glycol is required.

“For a data-centre operator, better heat transfer means more thermal headroom. That headroom can be used to run processors cooler, reduce the energy and flow required for cooling, or support more compute from the same cooling infrastructure. As AI chips become hotter and rack densities increase, we believe that becomes increasingly valuable.

"We now have application-tested technology, protected IP, production capacity at Ammanford and commercial agreements establishing our supply chain and route to market. Our priorities are now clear: complete qualification, convert the approximately 200 MW of active operator discussions into first deployments, and secure dedicated external capital for the venture.”

“SETTF is additive to our existing growth strategy, and our focus on delivering the Group’s commercial priorities across JustHeat, SaveMoneyCutCarbon and the wider business remains unchanged. The Company looks forward to providing a trading update, including for its SaveMoneyCutCarbon and JustHeat businesses, following the end of its financial year on 30 September 2026."

Ian Hopkins, Chief Commercial Officer of Levidian, commented:

“SETTF represents an exciting, high-value application for our G3 graphene. Levidian brings both materials-science capability and an international production platform that can support the venture as it scales into the markets where AI infrastructure investment is growing most rapidly. We look forward to working with Haydale and Liquitherm on qualification and first commercial deployments.”

Stephen Hickson, Group CEO & CTO of Liquitherm Technologies Group, commented:

“The SETTF test results are very encouraging. Achieving improved thermodynamic and hydrodynamic performance while retaining the requisite hydronic, biostatic and corrosion protection characteristics of a robust thermal fluid, operating within direct-to-chip cooling loops, could prove vital in enhancing chip performance (overclocking). Our focus is now on qualification and integration into our data-centre cooling fluid range and similar HVAC environments served by the Liquitherm group and our global partners.”

For further information:

About Haydale plc (www.haydale.com)

Haydale plc is an advanced materials and clean-technology company focused on the development and deployment of energy- and water-efficient technologies at scale. The Group's mission is to improve the energy, water and carbon performance of one million buildings.

The Group leverages its proprietary HDPlas® platform technology to develop patented graphene-enabled products that deliver measurable energy, water and carbon savings. These products are deployed through an integrated commercial model combining product innovation, customer access, delivery capability and Impact Partner relationships.

SaveMoneyCutCarbon operates as the Group's embedded B2B go-to-market platform, providing a national sales, programme management and installer network capability. Through its Impact Partner Programme, SMCC originates pre-qualified demand via long-term agreements with UK banks and utilities.

Haydale's strategy is focused on scaling the deployment of cost-effective decarbonisation solutions across the built environment, supported by measurable outcomes and financing structures that enable adoption.

Sources
 

[1] Shahi, P., Heydari, A., Hinge, C. et al. (2023), "Thermal, Hydraulic and Reliability Analysis of Single-Phase Liquid Coolants for Direct-to-Chip Cold Plate Cooling in High-Performance Computing Systems", Proceedings of ASME InterPACK 2023, paper IPACK2023-110576, doi:10.1115/IPACK2023-110576.

[2] International Association for the Properties of Water and Steam (2011), Release on the IAPWS Formulation 2011 for the Thermal Conductivity of Ordinary Water Substance.

[3] Infocom Media Development Authority, Singapore (2024), Green Data Centre Roadmap, pages 8, 9 and 13.

[4] NVIDIA (2026), "Hotter Than a Hot Tub: The 45°C Breakthrough to Cool AI's Biggest Machines", NVIDIA Blog.

[5] AMD (2025), AMD Instinct MI355X Platform datasheet.

[6] NVIDIA (2026), "NVIDIA Vera Rubin POD: Seven Chips, Five Rack-Scale Systems, One AI Supercomputer", NVIDIA Technical Blog.

[7] ASHRAE TC 9.9 (2026), Technical Bulletin: TCS Coolant Integrity and System Readiness Best Practices, page 2.

[8] ASTM D1384, Standard Test Method for Corrosion Test for Engine Coolants in Glassware; ASTM D8040-17, Standard Test Method for Corrosion Test for Heat Transfer Fluids in Glassware.

[9] JLL Research (2026), 2026 Global Data Center Outlook, pages 6, 16, 27 and 30.

[10] Hydromx Inc. (7 July 2022), “What Does Hydromx Cost?”, Hydromx website, accessed 14 September 2026. Hydromx states that it “usually costs 2–3 times greater than traditional glycol”, with the price difference typically delivering a payback of around three years.

[11] Alliance Chemical, Inhibited Propylene Glycol 25/75 with OAT Inhibitor — Data Center Coolant, product pricing accessed 14 September 2026. A 330 US gallon IBC tote is listed at US$4,820, equivalent to US$14.60 per US gallon or approximately US$3.86 per litre.

[12] UK Intellectual Property Office, patent GB2625980B.

Caution regarding forward looking statements

Certain statements in this announcement, are, or may be deemed to be, forward looking statements. Forward looking statements are identified by their use of terms and phrases such as ''believe'', ''could'', "should" ''envisage'', ''estimate'', ''intend'', ''may'', ''plan'', ''potentially'', ''will'' or the negative of those, variations or comparable expressions, including references to assumptions.  These forward-looking statements are not based on historical facts but rather on the Directors' current expectations and assumptions regarding the Company's future growth, results of operations, performance, future capital and other expenditures (including the amount, nature and sources of funding thereof), competitive advantages, business prospects and opportunities.  Such forward looking statements reflect the Directors' current beliefs and assumptions and are based on information currently available to the Directors.

A number of factors could cause actual results to differ materially from the results discussed in the forward-looking statements including risks associated with vulnerability to general economic and business conditions, competition, environmental and other regulatory changes, actions by governmental authorities, the availability of capital markets, reliance on key personnel, uninsured and underinsured losses and other factors, many of which are beyond the control of the Company.  Although any forward looking statements contained in this announcement are based upon what the Directors believe to be reasonable assumptions, the Company cannot assure investors that actual results will be consistent with such forward looking statements.  Accordingly, readers are cautioned not to place undue reliance on forward looking statements.  Subject to any continuing obligations under applicable law or any relevant AIM Rule requirements, in providing this information the Company does not undertake any obligation to publicly update or revise any of the forward looking statements or to advise of any change in events, conditions or circumstances on which any such statement is based.