Rethinking industrial heat: inside the Warnham brickworks project

Decarbonising industrial heat is one of the most complex challenges facing the construction supply chain today.

For manufacturers, where high-temperature processes are essential, reducing emissions while maintaining performance, quality and cost requires careful balance.

At wienerberger, we are addressing this challenge in practical, measurable ways. At our Warnham brickworks, a heat recovery and heat pump system is already showing how energy-intensive processes can be reimagined, delivering measurable emissions reductions while maintaining consistent production.  

The challenge: reducing emissions in energy-intensive manufacturing

Brick production relies on large-scale drying processes, where heated air removes moisture from clay products.

At Warnham, this process generated substantial volumes of warm, moisture-laden exhaust air, much of which was previously vented to atmosphere.

Capturing and reusing this low-grade heat presented a clear opportunity, but also a complex technical and operational challenge, particularly within a site running continuous production. 

As Greg Crownshaw, Thermal Process Engineer, explains:

“We could see there was energy leaving the process that we weren’t making full use of. The challenge was finding a way to recover it without disrupting how the factory runs day to day.”

The solution: turning waste heat into usable energy

At Warnham, that opportunity has now been realised.

The £4.5 million project, supported by the Industrial Energy Transformation Fund (IETF), combines heat recovery with industrial-scale heat pump technology to transform how energy is managed within the production process. 

Construction began in early 2024, with the system introduced in phases and fully installed by late 2025. This phased approach allowed the technology to be tested, refined and integrated while the factory remained fully operational.  

Delivered in partnership, the project brought together:

• Specialist design and engineering support from Heatcatcher
• Heat pump technology supplied by Seward
• wienerberger’s internal engineering and project teams 
• Technical expertise and concept development from wienerberger’s European colleagues

The system:

• Captures humid exhaust air from dryers
• Extracts latent heat through condensation
• Uses heat pumps to upgrade that heat to temperatures of up to 90°C 
• Reintroduces that energy back into the brick drying process

In parallel, recovered water is filtered and reused—improving overall resource efficiency.

Delivering measurable results

Following installation and commissioning in late 2025, the impact is already clear, with measurable improvements across carbon, energy and resource use. 

• Around 3,700 tonnes of CO₂ saved annually
• An average 60% reduction in dryer gas consumption, with some cycles achieving zero gas use
• Over 1.7 million litres of mains water saved to date, through capturing and reusing water within the process
• A continued shift from fossil fuels towards renewable electricity
• These improvements go beyond emissions reduction alone. They also contribute to:
• Greater energy resilience and reduced exposure to volatile gas prices
• More consistent drying, supporting product quality
• Lower resource use and reduced operational waste

As Greg Crownshaw adds:

“What’s important is that this isn’t just about reducing emissions. It’s about improving how the process performs overall — making it more efficient, more consistent and more future-ready.”

Why this matters

As the industry works to reduce embodied carbon and demonstrate real progress, attention is increasingly turning to how materials are produced, not just how they perform.

Projects like Warnham’s heat pump show that meaningful change is possible within existing manufacturing processes. By recovering and reusing energy that would otherwise be lost, it is possible to reduce reliance on fossil fuels, improve resource efficiency and maintain consistent output.

Crucially, this approach shows that decarbonisation does not have to come at the expense of reliability or scalability. Instead, it can strengthen resilience across the supply chain, helping the industry move forward with greater confidence.

A scalable model for industrial decarbonisation

The Warnham project is not just about what has been achieved, but what it makes possible next.

It shows how:

• Existing processes can be optimised rather than replaced
• Electrification and heat recovery technologies can be integrated into operational sites
• Proven solutions can be scaled and adapted across similar manufacturing environments

As Greg Crownshaw explains:

“This gives us something we can build on. We’ve been able to develop, test and refine the approach here, and that creates a strong foundation for applying it more widely.”

This moves industrial decarbonisation from concept to delivery, providing a practical model for wider adoption.

Building for what’s next

This project reflects how wienerberger is building for what’s next, applying innovation in ways that deliver measurable outcomes and support lower-carbon manufacturing. 

Work at Warnham continues, with further optimisation already underway. As these insights are applied more widely, the site is becoming a proven reference point, helping to accelerate the transition to more sustainable manufacturing across the business.

Crucially, the project contributes directly to wienerberger’s wider decarbonisation ambitions. By reducing emissions from one of the most energy-intensive stages of production, it supports the company’s target to achieve a 42% reduction in Scope 1 and 2 emissions by 2030 (from a 2020 baseline), while progressing towards long-term net-zero goals. This demonstrates how targeted innovation at site level can scale to deliver meaningful impact across the wider business and the construction supply chain.