How Irish Data Centres Are Achieving Energy Efficiency with Hot Aisle Containment
- DLS Interiors
- Oct 13, 2025
- 7 min read
In Ireland’s fast-growing data centre industry, energy efficiency is no longer just a target. It has become a core requirement. Rising electricity costs, higher IT loads, and sustainability expectations are pushing operators in Dublin and across Europe to rethink their cooling strategies. Among the most effective solutions available today is Hot Aisle Containment, often referred to as HACS.
By enclosing the hot aisles between server racks, HACS prevents warm exhaust air from mixing with the cold supply air. This simple yet powerful concept allows cooling systems to perform more efficiently, reduces fan and chiller demand, and improves energy performance across the board. In many European facilities, containment can cut cooling energy use by between five and eight percent, and sometimes even more.
At DLS Interiors, we specialise in professional HACS installation for data centres across Ireland and Europe. We do not supply containment systems. Instead, our expertise lies in designing and installing them correctly, integrating them with ceiling structures, sealing penetrations, and ensuring every installation meets the highest standards for safety and efficiency.
This article explains how Irish data centres are achieving measurable energy savings with Hot Aisle Containment, and how professional installation plays a key role in success.
Understanding Hot Aisle Containment
A Hot Aisle Containment System separates the hot air generated by IT equipment from the cold supply air delivered by the cooling system. Server racks are arranged in alternating hot and cold aisles. The cold aisle faces the front of the servers, where cold air enters, while the hot aisle captures warm exhaust air from the back of the racks.
HACS encloses the hot aisle with solid panels, doors, and overhead canopies. This enclosure traps the hot air and directs it back to the cooling units through a return duct or ceiling plenum. As a result, the air conditioning system can work more efficiently because the hot and cold air streams remain completely separated.
The concept is straightforward. Keep hot air and cold air apart, maintain a consistent airflow path, and seal any gaps that cause leaks. The result is stable temperatures, improved cooling efficiency, and lower operational costs.
Containment also allows operators to raise supply air temperatures while maintaining safe conditions for equipment. This means cooling units can run less intensively, reducing energy use without sacrificing reliability.
Why Containment Matters in Ireland
Ireland has become a hub for global data centre development. With dozens of major facilities operating nationwide, the sector now accounts for a significant share of the country’s total electricity demand. This has made energy efficiency a national priority.
Every improvement, even a small one, contributes to reducing pressure on the grid and supports Ireland’s broader climate goals. Hot Aisle Containment is one of the most accessible and effective ways to achieve these improvements because it builds upon existing cooling systems.
Many Irish facilities already track Power Usage Effectiveness (PUE), the key measure of data centre efficiency. HACS directly improves this metric by reducing non-IT energy consumption. It also helps data centres comply with the EU Code of Conduct for Data Centres and meet sustainability targets under ISO 50001 Energy Management Systems.
A clear business case supports containment. Lower energy consumption means reduced operational costs, longer equipment lifespan, and improved resilience against fluctuations in electricity pricing. For Irish operators, those advantages translate into both financial and environmental value.
The Benefits of Hot Aisle Containment
1. Improved Cooling Efficiency
HACS ensures that the air conditioning system cools only the cold air intake and not the mixed, turbulent air of traditional setups. The consistent separation of hot and cold zones results in a more efficient and stable airflow pattern.
2. Lower Energy Costs
Because the cooling equipment does not need to work as hard to maintain target temperatures, energy use declines. Even modest improvements in airflow can reduce energy bills significantly, especially in large-scale data halls.
3. Enhanced Equipment Protection
Hot Aisle Containment keeps rack inlet temperatures within recommended limits. By preventing thermal hotspots, it protects valuable IT equipment from overheating and reduces the risk of hardware failures.
4. Greater Reliability and Uptime
Consistent temperature control leads to fewer alarms and less unplanned downtime. Equipment operates within its designed temperature range, allowing data centres to maintain full reliability even during peak loads.
5. Sustainability and Compliance
Containment supports environmental objectives and helps Irish operators align with both national and European sustainability frameworks. It also strengthens ESG reporting by demonstrating tangible reductions in energy use.
Designing Containment Systems for Irish Data Halls
Implementing Hot Aisle Containment successfully requires careful planning and precise installation. At DLS Interiors, we focus on technical integration, safety, and performance. Each project is designed to suit the layout and operational needs of the facility.
Structural Ceiling Integration
Containment canopies or panels must be supported securely. Many modern data halls in Ireland use structural ceiling grids, such as Tate Grid, that allow safe mounting of containment panels, lighting, and cable trays. These systems reduce the need for drilling into soffits and simplify coordination with other trades.
Sealing and Leakage Control
Even small air leaks reduce containment performance. Proper sealing around doors, cable openings, tiles, and panels is essential. We recommend regular inspections and smoke testing to identify and fix any leaks that appear over time.
Fire Safety and Compliance
Containment must always comply with local fire codes and safety standards. Materials should be fire-rated, and access routes must remain clear. We coordinate with fire safety specialists to ensure full compliance without compromising airflow performance.
Coordination with Other Services
Cabling, HVAC, and lighting must integrate with the containment system. Heavy services should attach to the structural grid, not the containment panels. Every penetration is planned and sealed to maintain system integrity.
Phased Implementation
For live facilities, containment can be installed in phases to minimise disruption. Pilot rows are often used to validate design assumptions and refine installation details before scaling across the full data hall.
Retrofitting Versus New Builds
New builds offer the advantage of integrating containment from the design stage, allowing full coordination with structure and mechanical systems. However, retrofit projects in existing data centres can also achieve excellent results.
For retrofits, we start by surveying the space, identifying obstacles, and assessing airflow. The first step is usually to focus on high-density racks, where the benefits are most immediate. From there, containment can expand across other areas as operations allow.
In Dublin and other active markets, retrofitting is increasingly common because it provides a quick return on investment without the need for major construction.
Performance Results and Measured Outcomes
When properly installed and maintained, Hot Aisle Containment produces measurable improvements in data centre performance.
Energy Efficiency
Containment typically delivers cooling energy savings between five and eight percent. In some cases, especially where airflow management was poor before installation, reductions of up to thirty percent have been recorded.
Improved PUE
By reducing fan speeds and increasing return air temperatures, containment directly improves the Power Usage Effectiveness (PUE) of a facility. Many Irish operators report PUE improvements of 0.1 to 0.3 points following containment installation.
Temperature Stability
Consistent rack inlet temperatures lead to fewer thermal alarms, less maintenance, and improved overall reliability.
Increased Capacity
Because cooling efficiency improves, operators can often add additional IT load without increasing total cooling capacity.
Short Payback Period
Energy savings often offset installation costs within two to five years, depending on the size of the data hall and local energy prices.
Maintaining Long Term Performance
Containment is not a “set and forget” system.
To maintain peak performance, operators should:
Inspect seals and panels regularly.
Replace missing tiles or blanking plates immediately.
Conduct periodic smoke tests to identify leaks.
Include containment checks in their maintenance routines.
Assign a specific team member or contractor as the containment integrity owner.
Continuous monitoring ensures consistent performance and supports ongoing compliance with energy management systems.
Insights from Irish Data Centres
From our experience across multiple facilities in Ireland, several lessons consistently emerge:
Early coordination between ceiling, mechanical, and containment teams prevents rework and reduces cost.
Quality sealing has a greater effect on efficiency than many realise. Attention to detail makes all the difference.
Free cooling windows can increase when containment stabilises the environment, which further reduces energy use.
KPIs beyond PUE such as “percentage of time rack inlets remain within target range” help demonstrate operational value.
Phased rollouts allow teams to build confidence and fine-tune the process before full deployment.
Key Takeaways
Hot Aisle Containment separates hot and cold air, improving airflow management and reducing energy use.
In Ireland, containment aligns with sustainability goals and regulatory expectations.
Proper sealing, structural ceiling integration, and fire safety coordination are vital.
Both new build and retrofit facilities can benefit from professional HACS installation.
Long-term success depends on maintenance, monitoring, and clear ownership of system integrity.
Conclusion
Hot Aisle Containment is one of the smartest energy efficiency strategies available to modern data centres. It improves cooling performance, reduces energy costs, and supports compliance with both Irish and European sustainability standards.
For operators in Dublin and throughout Ireland, containment provides measurable improvements in Power Usage Effectiveness and long-term reliability. When designed and installed correctly, it becomes a permanent part of an energy-efficient, resilient, and future-ready data centre.
At DLS Interiors, we install HACS systems that are practical, compliant, and built to perform. We integrate containment seamlessly with your ceiling and partition structures to deliver long-term results you can trust.
If you are considering a new build or retrofit, contact our team today. We will help you design and install a containment solution that reduces energy use, supports uptime, and meets your sustainability goals.
Visit our Services page or Contact Us to start your project.
FAQs
1. What is a Hot Aisle Containment System?
It is a setup that encloses the hot air exhaust from server racks and directs it back to the cooling units. This prevents hot and cold air from mixing, improving efficiency.
2. How does containment save energy?
By separating air streams, the cooling system operates more efficiently, reducing the power required for fans and chillers.
3. Is HACS suitable for existing data centres?
Yes. Most Irish data centres can retrofit containment with minimal disruption through careful planning and phased installation.
4. What kind of savings can I expect?
Savings typically range between five and eight percent of total cooling energy use, with higher gains possible in inefficient setups.
5. Who can install HACS in Ireland?
A professional installation contractor like DLS Interiors, experienced in ceilings, partitions, and airflow systems, can ensure your containment is installed safely and correctly.
