Data centre racks that once drew a few kilowatts now host AI servers that draw many times more. At those densities, moving air alone becomes inefficient or simply impossible. That is why liquid cooling in data centres is moving from a niche option to a mainstream design consideration.
Liquid can carry far more heat than air, but adopting it changes the HVAC, plumbing, electrical and structural design of the facility. This article explains the options and what MEP teams should plan for.
Why Air Cooling Is Reaching Its Limits
Air has low heat capacity. As rack density rises, airflow volumes, fan power and containment complexity grow quickly. Eventually the room cannot move enough air to remove the heat, or the energy cost becomes unacceptable.
Liquids such as water and engineered coolants absorb and carry heat far more effectively, so they can remove it right at the source.
Main Types of Liquid Cooling
The ranges below are indicative and vary by vendor, design and facility. They show why different methods suit different densities.
- Rear-door heat exchangers: liquid-cooled doors mounted on racks that remove heat from exhaust air. This is often the easiest step up from air cooling.
- Direct-to-chip cooling: cold plates sit on processors and GPUs, and liquid carries heat away. Some heat still goes to air, so airflow is reduced but not eliminated.
- Immersion cooling: servers sit in tanks of dielectric fluid. This handles very high densities but requires new operating practices and layouts.
How the Heat Path Changes
In a typical direct-to-chip setup, a coolant distribution unit (CDU) separates the server-side loop from the facility water loop, protecting sensitive equipment and controlling temperature and flow.
Facility water can often run warmer than the chilled water used for air cooling. This can allow more hours of free cooling and reduce chiller use in suitable climates, a useful advantage in India’s varied conditions.
Impact on Electrical and Structural Design
- Higher rack densities mean heavier power distribution, busways and cooling of electrical rooms.
- Floor loading rises with liquid-filled piping, CDUs and immersion tanks
- Pumps and CDUs need backup power to protect equipment during a utility failure
Resilience and Commissioning
Data centre piping now becomes a core part of IT reliability. Designers must consider pipe material and cleanliness, filtration, water quality and treatment, isolation valves, expansion, and pressure testing. Leak detection under floors and at manifolds is essential. Lessons from our guide on commercial plumbing design on pressure, materials and testing apply here with tighter tolerances.
Planning Checklist for Owners
- Estimate current and future rack densities.
- Decide whether to build liquid-ready infrastructure now, even if servers arrive later.
- Reserve space for CDUs, piping and heat rejection.
- Confirm floor loading and ceiling or under-floor routes.
- Define leak detection, isolation and emergency response.
- Train operations teams on new maintenance procedures.
Frequently Asked Questions
Q – Will liquid cooling replace air cooling completely?
A – Not soon. Most facilities will run hybrid designs, as some components still need airflow.
Q – Is liquid cooling more energy efficient?
A – It can be, because it reduces fan power and enables warmer facility water, but results depend on the overall design.
Q – Can existing data centres be retrofitted?
A – Often yes, for example with rear-door heat exchangers or dedicated liquid-cooled halls, subject to structural and piping constraints.
Conclusion
Liquid cooling is becoming essential as AI and high-performance computing raise rack densities. It affects HVAC, plumbing, electrical and structural design alike, so success depends on integrated MEP planning from the start.
Owners who build liquid-ready infrastructure today will find it far easier and cheaper to scale tomorrow.
Planning a high-density data centre?
Our MEP team can design air, hybrid and liquid cooling solutions that are ready for tomorrow’s loads.