How to Retrofit a Colocation Data Center For High Density

January 14 2021

Market Insight

Scale Easily and Reduce Energy Consumption (and Costs) with Liquid Cooling

The pressure is on multi-tenant data center, or colocation, Facility Managers. Processor capacities continue to grow, generating more and more heat; each rack is hotter than before as packing densities increase, and overall thermal loads of colocation data centers are rising.

But don’t panic! You don’t need to overhaul your infrastructure. Retrofitting your facility is actually relatively simple when you choose the right enclosure cooling.

The Need to Stay Cool

The demand for more racks is inevitable. Customers of multi-tenant data centers need to know that they can rely on you as growth continues and density pack increases. Your immediate challenge is finding a hot-spot-reducing, high-density cooling solution that can be implemented during a retrofit, avoiding considerable infrastructure changes.

It’s clear that traditional air-based cooling — computer room air handlers (CRAHs) and computer room air conditioners (CRACs) — aren’t enough to get rooms cool enough, nor are they energy-efficient. You need to find something that gets cooling closer to the sources of heat (the equipment itself), addresses hot spots and reduces energy consumption and costs.

You likely have a data center infrastructure management (DCIM) program in place, providing a clear look into your equipment and facility infrastructure (primarily power and cooling). How will that change when retrofits and efficiency-upgrade initiatives become necessary? What climate control solutions can help you stay cool?

Why Liquid Cooling is the Solution

You already know all about air-based methods; cold air in massive amounts is mixed with heat from the equipment, dropping the room temperature to acceptable levels. Not a very efficient method, is it?

Developments in liquid cooling are offering methods for solving colocation facilities’ ongoing, and growing, heat challenges. In fact, according to the The U.S. Department of Energy (USDE), “As heat densities rise, liquid solutions become more attractive.”

The numbers say it all:

  • Traditional, air-cooled systems: 1kW–5kW rack power densities
  • Liquid-cooled systems: 5kW–80kW rack power densities

A liquid cooling system brings cooling close to the heat source, preventing hot spots and reducing energy waste (80% less air flow = a reduction in fan energy). A system can be implemented in a single enclosure, or cabinet, and it will cool as needed.

There are many types of liquid cooling systems:

  • Some use chilled water; others use dielectric fluid
  • Some are deployed within rows; others within single racks
  • Some are closed loop; others are open loop
  • And, as just mentioned, some methods are evaporative; others are immersion or direct-to-chip

You Have Options

The heads of multi-tenant data center owners and managers could start spinning when faced with multiple liquid cooling systems. The right type for your multi-tenant data center facility depends on your needs, thermal loads and infrastructure. Here’s a quick overview, but keep in mind that working with a colocation cooling systems expert for guidance is a vital move.

In row-based cooling, the units are placed within the row, cooling one or multiple enclosures/cabinets. Hot air travels away from the row, it’s cooled, and then it returns to the aisle.

During rack-based cooling, a fan and heat exchanger control the climate within each independent enclosure. No heat escapes into the room. Cooling is controlled (racks with less heat use less coolant).

Both liquid cooling systems are available in these designs:

  • Closed loop — All cooling takes place within the server cabinet. At the rear, hot air travels through a heat exchanger, and cold air travels to rackmount server air intakes. Solid doors keep air out of the aisle, so containment isn’t needed. Hot and cold air never mix, so efficiencies are greatly improved.
  • Open loop — Cooling units are located between server enclosures. Cabinet doors are perforated, allowing cold air to travel into the cold aisle from the cooling unit front; hot air, recovered from the hot aisle, travels over an air-to-water heat exchanger.

There are many liquid cooling methods and configurations available, each with unique benefits. Rittal offers row-based cooling systems that are open loop, as well as rack-based cooling that’s either open loop or closed loop. Plus, Rittal’s new HPC Cooled-by-ZutaCore solution — a direct-to-chip solution — efficiently brings a dielectric fluid to the chip and requires limited infrastructure changes.

So, what’s stopping you?

You’d like to make a decision and move away from air-based cooling to liquid cooling. But, maybe you’re concerned about the cost. This article covers the total cost of ownership of data center liquid cooling. Maybe you’re worried about how much effort it may take to implement a liquid cooling system. It’s easy to scale up a liquid cooling system as rack densities increase and as you need to add more racks, as this article explores.

When you do decide to talk to an expert in the field, consider Rittal, the global leader in enclosures. Companies around the globe rely on us to protect critical investments, ensuring the correct level of protection is provided to safeguard your mission critical deployment.

Ready for more? Our 12-page guide may interest you: Colocation Infrastructure Handbook. Get your copy of this resource that covers TS IT enclosures, IT cooling, and monitoring and security.