A rendering of DBT-Data’s 123,000-square-foot data center at 44610 Guilford Dr. in Ashburn. (Courtesy of DBT-Data)

Since the recession, Loudoun County has emerged as one of the biggest data center hubs in the country. Riding the tremendous growth in cloud computing, the area around Ashburn now rivals Silicon Valley, the New York suburbs and the Dallas area in data storage prowess.

There are more than 9 million square feet of data centers in Northern Virginia, including 5 million square feet in Loudoun County. And another 3 million square feet are planned or being developed in Loudoun.

Data centers have become the county’s dominant industry, producing $5.5 million in annual tax revenue, according to Buddy Rizer, acting director of the county’s Department of Economic Development. “It’s the biggest thing we have going. I think it’s really one of the great economic development stories around the country,” he said.

At the same time, Loudoun County is one of the fastest-growing residential markets in the region. During the decade ending in 2010, the county added more than 142,000 residents, outpacing every other Northern Virginia jurisdiction, and development has become a hot button issue in local elections.

There have been indications that data centers — industrial properties that require sizeable amounts of electricity and generators — could interfere with Loudoun’s reputation as a destination for new home buyers. County officials are considering a zoning ordinance amendment that would mostly encourage further development of data centers, but also could set limits on how loud they could be when located near residential areas.

Some want to head off the kind of attention one noisy data center attracted in North Carolina, west of Charlotte. There, the generator at a massive data center serving Facebook drew the ire of its rural neighbors for the buzzing sound it produced.

Data center industry experts, however, say they aren’t worried. DBT-Data, a real estate investment and development firm, recently closed on the acquisition of its fifth data center in Virginia, the 13-acre Cyber Integration Center in Harrisonburg. The center has a 2.5 megawatt diesel generator, said David Tolson, president of DBT Development, but it was wrapped in an enclosure that rendered the sound barely noticeable.

“You and I can literally stand outside next to it and it could kick on and we’d be able to carry on a conversation,” he said.

Pat Lynch, a managing director at real estate services firm CBRE whose team handles data center-related deals in Northern Virginia, agreed.

“You can put mufflers on them, you can locate them on the far side of buildings from where residents are,” he said.

Lynch said when data centers first began expanding, some were located on properties that were originally designed to house pre-Internet industrial uses and didn’t have the same technology operators are using today. But he said such concerns are not an issue with modern data centers, even as Loudoun County adds thousands of housing units.

“I think the industry is evolved and mature enough that I would not suspect that [conflict] to happen. Most of the large-scale data center developers in the market are very educated, very experienced,” he said.