Data center screening rules usually require generators, chillers, transformers and accessory substations to be fully screened from streets and neighboring lots by a building or a visually solid wall that suits the architecture, often with setbacks from homes and a separate noise study. Some codes allow perforated screening where equipment needs ventilation. The screen must keep each manufacturer’s airflow and service clearances.
Data center screening is the wall, building or planting that hides a data center's ground equipment yard from streets and neighbors: the backup generators, chillers and other cooling equipment, transformers and the accessory substation. Local data center rules almost always include a screening clause. This guide shows what adopted zoning codes ask for, where screening collides with equipment airflow, why a screen is not a noise barrier, and what to put in the submittal. The planner, the project's engineers and the equipment manufacturers make the final calls.
What do data center zoning regulations require for screening?
Most data center zoning regulations require ground equipment to be hidden from roads and adjoining property by a building or a visually solid wall, and many add setbacks from homes and a noise study. The clauses sit in use-specific standards or design review guidelines, so they are checked at site plan, special exception or design review.
Three adopted examples show the pattern:
| Example | Equipment covered | What the screen must be | Distance from homes |
|---|---|---|---|
| One county's zoning ordinance (adopted 2024) | Cooling, ventilating and power supply equipment, including generators, and any accessory substation | Fully enclosed unless that is not mechanically feasible under the manufacturer's specifications, then a wall or similar barrier. Ground equipment screened from abutting lots and roads by a visually solid wall or a building. | Ground equipment at least 300 feet from a residential lot line, or behind the data center building |
| Another county's zoning ordinance (2023) | All ground-level and rooftop data center mechanical equipment, plus refuse areas and loading bays | Fully screened on all sides by a visually solid screen compatible with the nearest principal facade. Perforated surfaces may be allowed for ventilation, as the zoning administrator decides. | Ground equipment separated from residential property by a principal building |
| One city's design review guidelines (adopted 2025) | All mechanical equipment, including transformers and generators | Fully screened by a building integrated with the development, or by a decorative screen wall with variation in colors, materials, patterns or textures, or an art installation | At least 150 feet from abutting right-of-way or residentially zoned property |
These are examples, not a national rule, and several jurisdictions are revising their data center standards now. Read the current code for your site and confirm the screening clause with the planner before the yard is laid out.
Which equipment has to be screened?
Expect the clause to cover everything that cools, ventilates or powers the building: generators, chillers and dry coolers, transformers, switchgear and the substation. One example also requires refuse areas to be fully screened on all sides and loading bays screened from roads and neighbors. Where a utility owns the substation, confirm early who designs its screen.
Building, wall or planting?
The codes prefer the building itself as the screen, with the yard behind it. Otherwise they ask for a visually solid wall that is compatible with the building or decorative in its own right. One example also requires drawings of the building and equipment as seen from every lot line and street line; show the screen's material and color there.
How tall should a data center equipment screen be?
Tall enough to hide the equipment from the viewpoints the code names. The examples above say "fully screened" or "screened from view" rather than giving a height, so the reviewer judges it from your sight lines. Generator enclosures, stacks, chillers on stands and transformers on pads can stand taller than a common fence, so set the height from the tallest scheduled unit, the grade and the nearest viewpoints.
Alpine Citadel screens come in standard heights of 6, 7 and 8 feet and are built from 5 to 10 feet, with other heights by engineering. Tall screens usually need a building permit and sealed calculations, so bring the building department in early.
How do you screen chillers and generators without starving them of air?
Keep each manufacturer's airflow and service clearances inside the screen, and use ventilated infill where the code allows it. This is the central conflict: the code wants the equipment hidden, and air-cooled equipment needs open air.
| Equipment | What one manufacturer's guidance says | What it means for the screen |
|---|---|---|
| Air-cooled chillers | One chiller catalog says walls around a unit in an enclosure should be no higher than the top of its fans, the unit should be open above the fan deck with no roof over it, and doubling the single-unit clearances between units is generally adequate. | A solid screen taller than the chillers can conflict with that guidance. The mechanical engineer decides between more distance, ventilated bays or the building as the screen. |
| Generators | One generator maker's installation guidelines call for at least 5 feet of clearance around each side for repair or replacement of major components, warn that nearby walls, fences and other barriers may inhibit airflow, and say not to face the radiator discharge into the prevailing wind. | Hold the service clearance inside the screen line, put access on the service sides, and keep the radiator discharge path open. |
| Transformers and substations | Utility and code clearances govern, along with the utility's access rules. See generator and transformer screening clearances. | Confirm clearances, gate locations and who holds the keys with the utility before drawing the screen. |
The codes leave room for this. The 2023 county ordinance above lets the zoning administrator accept perforated screening where equipment needs ventilation, and the 2024 one ties full enclosure to what the manufacturer's specifications make feasible. Get that determination in writing before the yard design is fixed.
The standard Alpine Citadel face is solid steel slats stacked tight, which is 100% opaque. Custom slat spacing and perforated metal panels are available where equipment needs air through the face, and a project can mix solid and ventilated bays around the same yard. Porous faces also reduce wind load, which the project calculation accounts for. How much each option screens and breathes is covered in the guide to mechanical equipment screening requirements.
Does a screen wall reduce data center noise?
No. A steel slat screen is a visual screen, not a noise barrier, and it should not be counted on to cut generator or chiller noise. Federal highway guidance says an effective noise barrier must be tall and long with no openings and built of rigid material weighing at least 20 kilograms per square meter. An equipment screen with ventilated bays, a gap at grade and an open top for airflow is the opposite of that.
Data center codes handle noise separately. The 2024 county ordinance above requires a noise study before site plan approval and a post-construction study with field measurements before the use permit. Its published study requirements call for a professional engineer specializing in acoustics, or a board-certified noise control engineer, with all cooling and other noise-generating equipment modeled at full load. Noise mitigation is the acoustical consultant's design, and it may change equipment selection, enclosures or location.
How should the equipment yard be laid out for access?
Plan the access first and the screen second. Sooner or later a generator, chiller or transformer has to come out and a new one go in.
- Change-out route. What is the largest unit, and can a truck and crane reach it through a gate?
- Service sides. Does a gate or opening face each unit's service side, with the maker's clearance kept clear?
- Fuel delivery. Where does the fuel truck stand, and can it reach the fill points without opening the whole yard?
- Refuse and loading. Is the trash area screened on all sides in the same system as the yard? Alpine builds trash and compactor enclosures in the same steel and finish.
- Fire separation. A slat screen is not a fire barrier. Clearances around generators, fuel tanks and any battery storage follow the fire code, and the screen does not reduce them. The guide to BESS and substation screening covers the NFPA 855 clearances.
Alpine Citadel gates are 12 or 16 feet clear as standard and 20 feet clear as a custom option, with multiple gates per enclosure where the layout needs them.
Does a data center screen wall need wind engineering?
Yes. A freestanding screen is a structure, and a tall solid one carries a large wind load. The design depends on the site's wind speed, exposure and risk category, and on the screen's height and infill; no single rating fits every site. Alpine Citadel is engineered to ASCE 7-22 for each site, on base plates or embedded posts, with sealed calculations available in all 50 states and an engineering package in under one week. See how Alpine engineers each site.
What should the data center screening submittal show?
Show the reviewer that every part of the clause is met. A complete package usually includes:
- The code section you are meeting, quoted on the sheet.
- Every piece of ground equipment, located and labelled, with its installed height.
- Setbacks from residential lot lines and rights-of-way, dimensioned.
- Screen height, and elevations or sight-line views from each lot line and street.
- Solid and ventilated bays marked, with the planner's acceptance of any perforation.
- Manufacturer airflow and service clearances drawn inside the screen.
- Gates, with clear widths, swing and the change-out route.
- Material and color keyed to the building facade.
- A reference to the separate noise study.
- Wind design criteria, and who provides sealed calculations.
How do campus developers standardize data center screening?
Write one screening detail family and adapt it to each county's clause. Developers building a phased campus, or the same design in several counties, save review time when the screen is a known, engineered system rather than a new design on every plan set. A detail that travels well sets height from the tallest scheduled unit, uses a solid face except where equipment needs air, matches the facade color, sizes gates to the largest change-out, screens refuse in the same system, and is engineered for wind at each site.
Alpine Citadel is built to the site or the architect's drawing in structural steel throughout, ASTM A36 or equivalent, with no aluminum components, in any RAL color. For phased campuses and multi-site programs, kits are packed by site and release. See Alpine's screen walls for equipment yards.
If you are laying out a generator or chiller yard, send the site plan, the equipment schedule and the screening clause through the Alpine quote request. Alpine will lay out the screen to your drawing and confirm heights, infill and gate options for the project.
Sources
- Fairfax County Board of Supervisors. Zoning Ordinance Amendment ZO 112.1-2024-9, Data Centers. Adopted September 10, 2024.
- Loudoun County. Zoning Ordinance, Chapter 4 Use-Specific Standards, Section 4.06.02 Data Centers. 2023.
- City of Phoenix. Zoning Ordinance, Section 507 Tab A, Guidelines for Design Review: Data Centers. Adopted 2025.
- Trane. Air-Cooled Scroll Chillers Model CGAM, Product Catalog CG-PRC017V-EN. 2025.
- Generac. Installation Guidelines for Stationary Industrial Generators. 2015.
- Federal Highway Administration. Highway Traffic Noise Barriers at a Glance. 2021.