Nigel Mallon, Business Development Manager for Data Centres at Weatherite, explores how heat recovery is transforming data centre efficiency. As energy demands rise, harnessing waste heat is becoming a vital strategy. This article examines how it supports sustainability, lowers emissions, and helps shape the future of data centre design.
As data centres expand to meet growing global demand, so too does their energy consumption. According to the International Energy Agency, data centres account for approximately 1-1.5% of global electricity use, with cooling systems representing a significant share of that footprint.
In the UK, where the shift toward sustainable digital infrastructure is accelerating, finding innovative ways to enhance efficiency and reduce emissions is critical. One of the most underutilised strategies in this space is heat recovery.
What is Heat Recovery and Why Does It Matter?
Heat recovery is the process of capturing and reusing heat that would otherwise be expelled as waste. In the context of data centres, this heat is primarily generated by the IT infrastructure and subsequently expelled by cooling systems working to maintain optimal conditions for high-density servers. Traditionally, this waste heat, or waste energy, would be vented directly to atmosphere.
Rather than venting this thermal energy into the atmosphere, it can be redirected to serve useful purposes such as pre-heating water, supporting HVAC operations in neighbouring buildings, or feeding into district heating networks.
With a typical data centre operating 24/7, the continuous generation of low-grade heat presents a consistent opportunity to improve both energy efficiency and environmental performance. From a sustainability perspective, integrating heat recovery aligns with Net Zero ambitions by reducing the site’s overall carbon footprint and enhancing Power Usage Effectiveness (PUE).
Sector Challenges and the Opportunity for Change
The drive to implement heat recovery comes at a time when data centre operators face mounting pressure to comply with environmental regulations, meet stakeholder ESG commitments, and lower operating costs. Yet, despite the benefits, adoption remains limited due to perceived challenges around integration, system compatibility, and real estate constraints.
Many legacy sites were not designed, or located geographically, with heat reuse in mind, and retrofitting such capabilities can pose logistical and cost-related obstacles. Additionally, engineers must navigate complex temperature differentials, site layouts, and compatibility between HVAC systems and heat recovery equipment.
However, modern HVAC solutions are increasingly being designed with modularity and integration in mind.
Products like Weatherite’s Pretec dual cool unit exemplify how innovation in cooling technology can open the door to scalable strategies. The Pretec range combines indirect cooling with integrated heat recovery potential, providing energy-efficient operation even under variable climate conditions. When paired with smart BMS platforms, the unit supports real-time performance monitoring and dynamic adjustment to maximise reuse potential.
Practical Applications of Heat Recovery in Data Centres
Heat recovery can be applied in several impactful ways within the data centre ecosystem:
- Domestic Hot Water Pre-Heating: Captured waste heat can be used to pre-heat water for staff facilities or adjacent buildings, reducing reliance on conventional heating systems.
- Space Heating for Ancillary Areas: Administrative offices, loading bays, and common areas can benefit from redirected thermal energy, improving internal comfort while cutting emissions.
- District Heating Networks: In urban or campus settings, excess heat from data centres can feed into shared heating systems that serve residential or commercial developments nearby.
- Support for Humidification Processes: Facilities using indirect free cooling or requiring specific humidity levels can recycle heat into moisture generation systems, supporting stable environmental control.
Each of these strategies not only helps reduce energy demand but also improves the overall thermal efficiency of the site. According to CIBSE, effective heat recovery can reduce a building’s heating demand by 20-30%, depending on usage and design.
Aligning Heat Recovery with Regulatory and Sustainability Goals
As the UK pushes forward with its Net Zero targets for 2050, data centres are increasingly required to demonstrate energy-efficient design under frameworks such as BREEAM, LEED, and the EU Code of Conduct for Data Centres. Heat recovery directly contributes to higher scores under these schemes by minimising environmental impact and enhancing energy performance.
Additionally, it helps reduce Scope 1 and Scope 2 emissions, a key priority for companies reporting under the Streamlined Energy and Carbon Reporting (SECR) regulations or adhering to Science-Based Targets.
Looking Ahead: Heat Recovery as Standard Practice
While early adoption of heat recovery in data centres has been sporadic, the combination of environmental necessity, maturing technologies, and economic incentives is shifting the conversation.
Forward-thinking organisations are already embedding heat reuse into their design briefs, recognising it as an opportunity to differentiate their operations and add long-term resilience.
Weatherite, with over 50 years of experience in HVAC innovation, continues to support this transition. By working closely with clients in the data centre sector, we’re helping to design, manufacture, and implement advanced cooling systems that incorporate heat recovery without compromising operational performance. Our UK-based manufacturing and engineering expertise ensure that every solution is tailored to the specific thermal and spatial requirements of the site.
Key Takeaway
- Heat recovery presents a practical, impactful path to improving data centre efficiency and reducing environmental impact.
- As operators continue to face growing expectations around sustainability and operational transparency, the ability to turn waste heat into a resource rather than a liability will become increasingly vital.
- Through collaborative design, smarter HVAC systems, and a renewed focus on performance-driven engineering, heat recovery can evolve from an afterthought to a cornerstone of future-ready data centre construction.
Nigel Mallon, Business Development Manager for Data Centres at Weatherite, a HVAC solutions provider. Nigel started out as a mechanical Estimator 13 years ago and has work in various positions designing AHUs, thus gaining valuable experience from each project. Currently leading up the sales and technical support as Business Development Manager.
For more information about Weatherite, please visit: www.weatheritegroup.com or call us on +44 (0) 121 665 2266.