Over the years we’ve published countless articles on our blog related to airflow management, cooling optimization, data center efficiency, and many others. Today we take a look back at the top articles of all time on The Upsite Blog.

1. Hot Aisle Containment vs. Cold Aisle Containment: Which is Better for the Data Center?

Containment has gone mainstream in the past few years in the data center industry, which has led to widespread implementation and adoption by many sites. In fact, according to a recent survey by the Uptime Institute, 80% of sites have implemented either hot or cold aisle containment. While the survey represented mostly larger facilities, many medium and small facilities have either implemented or are considering some form of containment. This high rate of adoption has left a lot of people asking the same question: Is it better to contain the hot aisle or the cold aisle?

2. The 4 Delta T’s of Data Center Cooling: What You’re Missing

When was the last time you had a conversation with anyone trying to sell you something for your data center and Delta T (ΔT) didn’t pop up at least a couple times? This bit of jargon is so pervasive in our industry that no one is surprised to hear “Delta T” as a slick rock band parody of the Beatle’s “Let It Be” at conference parties and hospitality suites. It’s just as natural. Nevertheless, there is a little more to ΔT than is typically understood.

3. What Is the Difference Between ASHRAE’s Recommended and Allowable Data Center Environmental Limits?

Despite the ubiquity of references to ASHRAE TC9.9’s guidelines on data center temperatures, there remain questions about the difference between the recommended limits and the allowable limits. The easy answer is that the recommended envelope for server inlet temperatures is 18-27˚C (64.4 – 80.6˚F) and the allowable envelope is wider, depending on the server class. But in actual application, what is the difference between a recommendation and something that is allowable? How do you know which to apply?

4. Perforated Tile Placement: Why the Right Location Matters

It’s common knowledge that perforated tiles are a vital aspect of the cooling process in any raised floor data center. After all, that is how you deliver the supply air to the cold aisle and ultimately to the inlets of the IT equipment. Yet, managing the placement of those perforated tiles is a strategic component of airflow management that is often overlooked. For example, of 45 sites we reviewed worldwide, only 7.5% had properly placed all of their perforated tiles.

5. IT Equipment Delta T and Flow Rate: How They Impact Your Data Center

As we recently discussed, reducing bypass airflow is key to increasing cooling capacity and reducing operating costs. Airflow management improvements allow for the reduction of conditioned airflow rates from cooling units, either by reducing fan speeds or by turning units off. This reduces the amount of bypass airflow in the room by making the delivered flow rate of conditioned air closer to the flow rate required by IT equipment. An understanding of IT equipment flow rates will help you to further refine the cooling efficiency and capacity and help you make informed decisions about procuring IT equipment in the future.