In the past few decades, we’ve made great strides in improving the efficiency of cooling systems for electronics. How? By keeping cold air separate from hot air by routing them through different vents. Early on, this involved flooding rooms with cool air—only to find that these efforts were too expensive because the hot exhaust air would find its way back. We also added a lot of margins—and money—to the system just to be safe.
Today, to keep each device at an appropriate operating temperature, current equipment designs require a constant flow of air. And we are aware that efficiency is increased when the cold supply air is not mixed with the hot exhaust air. Therefore, is it possible to achieve both goals?
Some vendors have recently developed an ideal way to keep a room cool. Their design system features the ceiling plenum as a hot air return plenum and racks equipped with exhaust chimneys. This process allows for all of the heat generated from the computer servers or other equipment to be sucked up into these vents so they can then flow back out again, creating a warm air-cooling effect throughout the entire room without exposing any of it to outside sources. They’ve even found ways for this venting system to go one step further—by enclosing it in metal walls that feature ducts carrying cold air alongside them. What does this mean? Now you can control whether this space is warm or not—without affecting how the equipment functions!
In the current datacom environment, it’s neither free nor simple to achieve this cooling utopia. So, what can be done since purchasing new racks is not an option right now? What happens if the ceiling plenum that normally acts as the hot air return plenum doesn’t exist or isn’t readily available?
Practical solutions exist for approximating the ideal layout outlined earlier. One such solution is to separate hot and cold aisles, isolating them from the rest of the room. This means that there will no longer be mixed supply and exhaust airstreams; instead, these are isolated so are controlled separately—potentially increasing the supply air temperature and reducing energy costs. The most cost-effective solution is using curtains suspended from the ceiling down either side of racks on either side of the aisle. This system’s options make it a great temporary solution while you plan and get ready for the long-term ideal cooling solution.
