Millions of words have been written and said about data centers, but for lots of people, they may as well just be a series of four-letter words.
The Phoenix area is one of the biggest markets for data centers in the country, and proposed new developments have raised questions in communities across the state. Many of those questions focus on water and power, and there’s been a lot of reporting on data centers’ environmental impacts. But the questions don’t end there.
How do data centers work?
Why do we need them?
What do they do?
The Show set out to answer those questions — and others — in Centers of Attention. In this three-part series, we’ll look at how data centers work, why some communities want them and others don’t and the impact they can have.
Today, we start on the inside.
On a sunny winter day in early 2026, the air is unusually chilly for Phoenix, but the cool temperatures remain constant inside any data center, including one run by a company called Iron Mountain. You may remember Iron Mountain as a paper storage company; they now also store data.
This particular center is one of three buildings at roughly 48th Street and Loop 202 — pretty close to the airport, a few freeways and downtown Phoenix. And it’s big. Really big. Like, 540,000 square feet big.
Not just anyone can access a data center. It took KJZZ months to find a willing company, and weeks beyond that to actually arrange a tour. Security is tight.
Jason Pfaff is Iron Mountain’s general manager for North America — and today’s tour guide.
“So, the building that we’re in today, it has upwards of 300 customers — some of those range from a single cabinet all the way up to custom suites that are built for them,” he said.
This building is what’s known as a ‘co-location’ facility — meaning there are different companies of different sizes with different needs that have servers inside. It could be telecommunications companies, or health care organizations. The names of those firms, by the way, were not part of the tour; we were told clients like their anonymity when it comes to this kind of thing.
Those companies basically rent space for cloud storage, AI and processing transactions, among other things.
Pfaff explains.
“So, what we try to do is take away those things that aren’t inherent to what they’re trying to do, right? So, they have their business they’re running — we want to take all of the electrical, mechanical, security — all of those worries off of their plate, so that they can just run their business.”
Pfaff says data centers have been around since the early days of computers and servers. But back then, he says, data centers were shoved into closets or wherever else a company could find space. Now, some companies — think Amazon or Microsoft — have big data centers like this one all to themselves, while others share space.
One of the other warehouse-sized buildings on the campus has only one customer, while the third has a few. Iron Mountain declined to name any of the businesses at this location. But Pfaff did offer a glimpse of the action.
“So, what you’re seeing now, this gives you a really good view of what a co-location facility looks like,” Pfaff said. What we’re looking at now is [an] open room here with cabinets, cages, private suites, all those that allow customers to come in and take space. And then right in front of us is what we call a main distribution frame — one of the things that people come here for is connectivity — well, this is how we do that connectivity out to the data center.
“So, every one of those cables that you see on all this goes to a customer, and that’s how they connect to the internet, connect to each other — all those types of things.”
To get a sense of it, picture a space even larger than your typical big box store. But instead of TVs or refrigerators, there are cables, cabinets and cages.
There’s also a lot of security — you really can’t get anywhere without proving you’re supposed to be there. Visitors— including Iron Mountain execs — are required to stand in a small vertical tube where their eyes are scanned. Once approved, the door to the tube opens.
The tour continues on to what Pfaff calls “Phase 2.” This section is a less-massive open room including more small cabinets — and it’s much quieter. Pfaff says these spaces were built specifically for customers’ needs.
“Everything’s contained within these, the modules that we’re looking at. Whereas the data center where we came out before, you were in the open area in the data center. The data center is now inside of the box that you’re looking at. So, that’s why you don’t hear it.”
But does the same thing happen, as in the larger room?
“Absolutely,” Pfaff said. "No matter what data center you have, you’re removing heat, right? So, you’re bringing power in and you’re using the chillers and the cooling to remove that heat. So, I’ll open the door here, and you can see it’s noisy inside, just like before.”
And it is.
These modular facilities more closely align with how Iron Mountain says it’s building new data centers — smaller space, more efficient, according to Pfaff. This building was originally a bottling facility, so the specs aren’t exactly ideal for a data center. Higher ceilings, for example, mean more space to cool.
This particular facility also has something called the "meet-me room." Pfaff explains this is the spot where all the carriers bring their fiber, so data center customers can connect to it. And that connectivity is really key to the whole operation. Standing inside the data center, it’s not hard to see — and hear — all the cables, wires, servers and other equipment doing their thing.
But what exactly is their thing? We asked YZ Yang, an associate professor in Arizona State University's School of Computing and Augmented Intelligence.
“In a nutshell, a data center is basically a farm of computing hardwares,” he explained.
Yang says the machines in the data centers are doing the heavy lifting for a lot of what we do on our phones and computers every day.
“The input and what you are interacting [with] on your cell phone is just the front end. So, the front end takes in the question — it’s through the internet sent to the data center and the data center, in some of the machines, is doing the processing for you.”
The amount of processing — or storage space — you need depends on what you’re doing, whether it’s opening a Google Doc, asking AI a question or storing all those vacation photos in the cloud.
And that’s just the stuff we’re doing on our own personal devices. Iron Mountain’s Jason Pfaff points out there’s other technology out there that also needs lots of processing.
“One self-driving car creates somewhere between one and 15-20 terabytes of data per day. So, if you think in 10 years, you know, how many cars might be on the road that are self-driving, all of that data has to sit in a data center.”
To put that into perspective, online estimates suggest 15 terabytes would get you enough space to store nearly 4 million photos.
Pfaff gets why people feel nervous — or worse — about data centers ending up in their communities: They’re big, they use a lot of power, they’re noisy, there are concerns about water use. But he says we like our tech and our conveniences, so — data centers might be inevitable.
“I heard something one time, you know, somebody said, ‘Why do we need data centers? I can do everything I want right here on my phone,'" Pfaff said. "Well, everything you do on your phone or your computer at home all happens in a data center. All of that data, every selfie you take, every social media post you do sits in a data center. So, unless we can figure out how to store stuff not on physical equipment, which I don’t see how you ever are able to do that, you’re going to need data centers."
Pfaff says we just keep creating more demand from our phones, AI and smart devices — and that data has to go somewhere. At least, it does if we want to keep it. And he says ideally, that somewhere should be relatively close to where the demand is coming from.
“Anytime you go onto your phone, anytime you do a search, anytime you’re streaming on your thing, the closer you are to where that data sits, the less latency you’re gonna have, the faster it’s gonna work, the faster things are gonna perform for you. So, the closer you can be to it, the better.”
But how close is close enough? Could we end up with neighborhood data centers? Pfaff didn’t say yes — but he also didn’t say no.
Mark Bauer is vice chairman at the real estate firm JLL in their data center solutions group. He joined the Iron Mountain tour, as his clients rent space there and in other data centers. He doesn’t think the idea is so far-fetched.
“I think we’re gonna see more data centers but smaller data centers spread out through a community.”
And those communities will likely continue to be in the Valley. Pfaff says Phoenix is probably the second biggest market in terms of data center demand, behind only Virginia. And Bauer says one reason why is another of the area’s growing industries.
“We’ve now got some of the largest technology companies right here. Then you add on our, you’ve got the semiconductor industry — I think that’s a big component,” Bauer said.
“The semiconductor industry is producing these chips for companies all over the world, but many of them are right here, too. These chips go into data centers, so I think that’s why Phoenix has just exploded.”
That explosion is happening very differently on opposite sides of the Valley. More on that Wednesday, as The Show series, Centers of Attention, continues.
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