An enterprise data center is run by an organization, internally, for its own use.[1] It is usually built into a larger building and managed with the organization’s own IT systems.[1] Under a White House budget office memo, federal agencies report a purpose-built, physically separate, dedicated space as a “tiered” data center when it meets set criteria.[2] This is federal reporting only, and the criteria are in instructions this site did not capture. Cloud services from private companies do not count as agency data centers under that memo.[2]
Explore in 3D
The same numbered parts as the drawing, as a model you can turn. Illustration, not to scale.
3D is not available here. The drawing above and the text below show the same parts.
How it works, part by part
- Host building. The data center is usually one part of a larger building, with the organization’s other rooms around it.[1]
- Grid connection. Brings electricity from the grid into the building, through a transformer that lowers its voltage.[3] In the guide: Grid connection and substation
- Switchgear and transformers. Transformers change the voltage. Switchgear, a mix of disconnect switches and circuit breakers, controls and protects the electrical equipment and can isolate parts of it.[4] In the guide: Transformers and switchgear
- Uninterruptible power supply (UPS). Provides backup power, and can run on battery banks or other technologies.[5] In the guide: Transformers and switchgear
- Backup generators. Give the site another source of power if the grid’s supply stops.[5] In the guide: Backup generators
- Computer room. A dedicated room for the organization’s equipment.[2] In the guide: Data halls and servers
- Server racks. Hold the organization’s own computing equipment, which runs continuously.[1] In the guide: Data halls and servers
- Room cooling unit. Cools the room’s air by running refrigerant through indoor coils.[1] In the guide: Cooling inside the building
- Outdoor cooling equipment. Moves the heat outside. Air-cooled systems do it with condensers that use outdoor air.[1] In the guide: Heat out
- Second site. Some organizations run a second site for redundancy, as Connecticut’s state data center service does. Drawn in outline, with no location implied.[6]
How power moves
- True of data centers generally Power usually arrives from the utility at a higher voltage. A transformer steps it down, and it passes through switchgear and backup equipment before it is shared out to the racks.[4] Parts 2, 3, 4, 5
- This type A national lab’s model assumes power-supply efficiency for internal sites sits between small sites and hyperscale.[1] That assumption also covers colocation and communications data centers, so it does not set this type apart, and it is not a ranking. Part 4
- One example At the example, the plan lists two electric services with transformers and two backup generators.[7] Parts 2, 5
How heat moves
- True of data centers generally In air-cooled halls, the aim is to keep cooling air from mixing with hot exhaust air.[5] Parts 6, 7
- True of data centers generally Refrigerant-based room units are common in small and midsize data centers.[1] Part 8
- One example At the example, the operator’s report says it chose heat recovery and geothermal heating and cooling early in the building’s design.[8] That describes the whole building, not the data center alone. Part 9
How this type differs
These differences come from how the sources define each type. None of them makes one type preferable.
- A colocation operator leases space to others. Here the operator runs the space for itself.[1] Colocation and leased campuses
- Internal sites are midsize on average, about 2,700 square feet.[1] That is an average for the category, not any one site. Hyperscale campus
- Branch-office closets and server rooms are smaller still, and are counted separately.[1] Edge sites
- Internal sites dominated the industry in the early 2010s, and estimates since then show a shift toward hyperscale and colocation.[1] Hyperscale campus
One real example
VELCO New Haven Operations Facility is one example of this type, chosen by hand. It is one of 5 such examples; most records on this site are not typed, including 3,110 of the 3,115 source listings on the opening map, which can overlap.
A Vermont utility, VELCO, says the facility will keep its operations, IT and data systems running during an emergency. It serves that utility rather than tenants.[7]
- The utility’s project page says the project combines a backup operations center, a training facility, a data center and an incident command center.[7]
- The town plan describes an 18,000-square-foot backup operations and data center.[9]
- The project page lists two electric services with transformers and two backup generators.[7]
- The utility’s report says it chose heat recovery and geothermal heating and cooling early in the building’s design.[8]
This site’s record says current construction progress and as-built scale are not established. The floor area above is a planned multi-use building, not data-hall area.
Questions to ask about a project of this type
- Which organization runs it, and does it serve only that organization?
- Is it a separate building or a room inside a larger one?
- Is it the main site or a backup, and where is the other site?
- What keeps it running in a power loss: how many feeds, batteries and generators?
- For a public agency, is the space owned or leased, and what does the agency report about it?
Go further on this site
All types of data center · How data centers work · The 3D map · A megawatt of what?
Sources
- 2024 United States Data Center Energy Usage Report (LBNL-2001637). Lawrence Berkeley National Laboratory. National laboratory. Cited at Table 4.1, p. 36; p. 36; p. 40; pp. 42-43; p. 35; p. 37. Captured 3 November 2026.
- M-19-19, Update to Data Center Optimization Initiative. Executive Office of the President, Office of Management and Budget. Government. Cited at p. 4; p. 5. Captured 3 November 2026.
- Electricity explained: How electricity is delivered to consumers. U.S. Energy Information Administration. Government. Cited at How electricity is delivered. Captured 3 November 2026.
- Data Center Power Equipment Thermal Guidelines and Best Practices, TC 9.9 white paper. ASHRAE Technical Committee 9.9. Standards group. Cited at section 4; power distribution overview. Captured 3 November 2026.
- Best Practices Guide for Energy-Efficient Data Center Design (revised July 2024). U.S. Department of Energy, Federal Energy Management Program. Government. Cited at section 6.1.1; section 6.1; section 4. Captured 2 November 2026.
- Statewide Data Center Facilities. Connecticut Department of Administrative Services. Government. Cited at Overview. Captured 3 November 2026.
- New Haven Operations Facility project page. Vermont Electric Power Company (VELCO). Company document. Cited at Project Highlights. Captured 3 November 2026.
- VELCO 2024 Environmental, Social, Governance Report. Vermont Electric Power Company (VELCO). Company document. Cited at p. 15, Facilities. Captured 3 November 2026.
- 2025 New Haven Town Plan. Town of New Haven, Vermont, hosted by the State of Vermont. Government. Cited at Energy Plan section. Captured 3 November 2026.
Sources were captured on the date shown and can change. An operator’s explanation is used only for how a part works, never for a definition or a comparison.