Category Archive: Electronic Equipment Rack Features

An Introduction to Liquid Cooling for Rack Enclosures

Power densities in electronic subsystems continue to increase, driving demand for more extreme cooling power. System engineers are increasingly exploring liquid cooling to optimize thermal management efficiency, sustainability and reliability.

Liquid cooling is replacing air cooling for several reasons: 3,500 to 4,000 times more efficient at transferring heat; noise reduced due to slower fan speed; 85% reduction in carbon footprint; and significant cost savings results from more efficient cooling because less energy is required. Read more about IBM’s experiment from 2010 in Scientific American.

Fluids commonly used in cooling applications

  • Water – excellent heat transfer, low viscosity, non-flammable and low cost. Susceptible to freezing or boiling and biological fouling.
  • Ethylene glycol (EG) – controls biological growth, lowers freezing point and elevates boiling point when used in solution with water. Lower cost that refrigerants or dielectrics. Highly toxic and requires careful handling.
  • Propylene glycol (PG) – controls biological growth when used in solution with water. Lower cost than refrigerants or dielectrics. Lower thermal conductivity and higher viscosity than EG. Low toxicity for easier handling and disposal.
  • Mineral oil – odorless, non-toxic and chemically inert. No evaporation or volatility. Potential incompatibility with copper or some elastomers.
  • Refrigerants – lightweight with excellent thermal transfer properties. Higher cost (R-1234yf and R-1336)
  • Dielectrics – non-conductive engineered fluids that enable full immersion of electronics in single-phase, two-phase and direct-to-chip applications. Low boiling point and higher chemical stability. Higher cost. Potential incompatibility with thermoplastics or elastomers.

Factors to consider when choosing a coolant for your liquid cooled rack or enclosure

Choosing a coolant is a focal point when designing a liquid cooling system.

Start by looking at operating and storage temperatures. You’ll want to identify a fluid with properties that are compatible with your application’s environment, such as boiling point of the thermal load and thermal efficiency needed without exceeding the critical heat flux. It’s also critical to check low temperature characteristics during storage and shipping or other environmental exposures.

We recommend considering the ozone depletion and global warming potentials when selecting a fluid. Over the last decade, the World Health Organization guidelines have increased emphasis on these parameters, prompting the development of greener alternatives, such as 3M Novec (will be discontinued in 2025), FHE coolant and fourth generation hydrofluoroolefin refrigerants.

In addition to thermal stability and chemical compatibilities, consider coolant toxicity, flammability, cleanliness requirements, environmental impact, and cost.

Component construction materials commonly used


  • Commodity plastics – includes HDPE, POM, PP, PS and PVC. Relatively low cost and readily available. Potential flammability in high-temperature applications or thermal degradation and shrinkage in some environments.
  • Engineered thermoplastics – includes PEEK, PEI, PESU, PPSU, PSU. Improved mechanical and thermal properties, with a higher cost than commodity plastics.
  • Elastomers – includes CR, EDPM/EPM, FKM, HNBR, silicone. May be modified to enhance flame retardance, durability or chemical resistance. Some types may leach into fluids during thermal cycling or exposure to certain solvents, negatively impacting coolant performance.

Metal alloys

  • Aluminum – durable, lightweight metal with strong thermal properties. Potential for galvanic corrosion, especially with water-based coolants and in presence of copper. Anodization increases corrosion resistance.
  • Brass – durable and strong thermal properties. Relatively low cost and often plated with nickel or chrome for improved corrosion resistance.
  • Copper – durable and strong thermal properties. Galvanic corrosion potential, especially with water-based coolants.
  • Stainless steel – Highest in durability and stability, but lower thermal conductivity and higher costs. Passivation increases corrosion resistance.

Material and coolant compatibility

When considering components in a liquid cooling system, the following combinations are:

  • A = recommended. Little to no potential for chemical reaction or corrosion.
  • B = good options. Minor potential for chemical reaction or corrosion, with limited affect on system performance.
  • F = not recommended. Mild to severe chemical or corrosive reactions likely. May impede system performance.


Ethylene glycol (EG)

Proplyene glycol (PG)

Mineral oil



Commodity plastics







Engineered thermoplastics





A to F







A to F

A to F






















Stainless steel







Connectors for a liquid cooled rack enclosure

Connectors are critical to the safe and reliable operation of liquid cooling systems. A well-design fluid connector should easily facilitate connection, disconnection and rerouting of fluid; support 100% uptime during installation, reconfiguration and maintenance; and allow secure, efficient, reliable and leak-free management of fluids within the cooling system.

Connector type

  • Quick disconnects (QDs) – increasingly used because they’re easier to install/uninstall than other connectors
  • Socket/plug; male/female; body/insert – connector halves fit together by one side inserting into the other. They’re intuitive to use and requires force to connect, which increases as the system pressure increases
  • Latched – integrated thumb latches can ease connection/disconnection by allowing one-handed operation; enables hot swapping
  • Blind mate – requires a separate retention mechanism, such as a sever blade latch; releasing force disconnects the QD and works best in difficult to see/access locations
  • QDs with elbows, swivel joints – integrated swivel joints and elbows eliminate tube kinking and allow easier connection and disconnection in tight spaces

Flow rate, pressure and pressure drop

  • Flow rate – flow rates are typically low at the server (o.5 l/min) and much higher at the coolant distribution unit (up to 70 l/min); actual-use flow rates that exceed the connector’s maximum flow rate capacity can lead to seal failure or accelerated part erosion.
  • Connector size – specify appropriate connector sizes from server to CDU. They range from 1/8 inch at the server to 1 inch at the CDU. QDs of the same size can deliver significantly different flow performance. Also consider physical space available at the front or back to ensure adequate room for connections, disconnections and ongoing use.
  • Pressure – operating break and safety burst pressures should all be assessed. Operating pressure defines the usual and customary pressure ranges during regular system use. Break pressure indicates the point at which a component no longer maintains pressure, which is a higher threshold than safety burst pressure.
  • Pressure drop – both flow rate and connector size affect pressure drop

Stop-flow / dripless performance

  • Straight-through connectors – neither connector half features a valve necessitating flow stop prior to disconnection
  • Single shut-off valve – one side of the QD contains a valve
  • Double shut-off valve – both QD halves contain valves; poppet valves trap a small amount of liquid within the coupling body that can drip when disconnected
  • Flush-face valves – most dripless/drybreak/non-spill QDs feature flush-face valves that allow no more than a coating of coolant on valve surfaces
  • Seal type – many QDs feature O-rings; some connectors feature multilobed seals that offer better shape retention over time, protection against leakage, greater resistance to debris or foreign contaminants, and require less force to connect


  • Helium vacuum leak test – verifies sealing performance at specific temperatures
  • Elevated temperature burst test – demonstrates adequate safety margins above rated operating pressure at higher than ambient temperatures
  • Creep rupture test – demonstrates safe use at continuous higher-than-rated pressures and temperatures for an extended period
  • Flow rate test – determines CV values
  • Drip leak testing and spillage testing – under specific temperature and pressure conditions, measure evidence of drip leaks during simulated use conditions or spillage at disconnection
  • Disconnect under flow – quantify resistance of connectors to water hammer and fluid acceleration caused by disconnecting units under flow
  • Cycle testing – verifies connector sealing performance after repeated connection/disconnection cycles; some manufacturers conduct 10,000 cycles to validate leak-free performance
  • Connect force testing – characterize the force to connect with varying pressures in the disconnected body and insert prior to connection

Identifying the Correct Electrical Enclosure Gasketing

First, let’s identify if or why you need to use electrical enclosure gasketing. The function of a gasket is to not only protect electronic components contained in electrical housings from outside elements such as weather, but also to prevent electrical hazards from escaping the unit. The proper gasket will provide a tight seal in both indoor and outdoor enclosure applications, with the ability to withstand the life of the product.

Poor seals and low-quality gaskets can cause damage and serious safety issues. An inefficient design can allow gases and liquids to leak into your devices, it can cause system failures that require time-consuming repairs or even fires that put your facility and employees at risk.

Ensuring proper performance for your enclosure gasketing

Before you make material selections and/or installation options, it’s important to understand your specific application requirements. Most applications need to comply with various ratings such as NEMA, UL and IP or military standards.

Ask the following questions:

  • Temperature – what temperature range will be required?
  • Location – will the application be indoor or outdoor?
  • Flame resistance – will the material require a certain flame rating?
  • Outgassing – will material outgassing harm the internal components?
  • Gap spacing – what is the area needed to be filled by the gasket?
  • Gasket function – what protection will the gasket need to provide? (air, liquid, vibration, EMI shielding)

Additional engineering design considerations:

  • Protect the gasket – a flange on the door that protects the gasket from a direct pressure blast will diffuse the force and greatly improve the chances of passing a wash down test
  • Door latching – helps provide a proper means of compressing the gasket
  • Material selection – ensure the appropriate gasket material is used for your environmental requirements
  • Gasket rebound – rebound or resistance to taking a compression set can be critical, especially on door gaskets that are being unseated regularly
  • Functional life – longevity of the gasket will depend on how the material is used: exposure to UV, ozone, temperature, chemicals, and mechanical wear
  • Venting – pooled water can get sucked into an enclosure during a rain shower from the vacuum affect from cool rain on a hot box

Material selection for your enclosure gaskets

There are a variety of materials to choose from when it comes to providing the perfect seal on an enclosure. Look for an option that is both cost-effective and delivers optimum performance.

Common materials used:

  • closed cell sponge rubber (neoprene, PVC)
  • cellular urethane
  • polyethylene
  • silicone

Which application process should you utilize?

There are three common types of gaskets:

  • Foam-in-place – they require a special liquid polyurethane spray to be applied to the edges of the mating, that once dried and hardened can provide a good deal. A downside to this option is that it can easily be damaged and can be a costly application process
  • Strips – these are typically used as a temporary solution until a better gasket option can be found. It often leaves gaps and leaks.
  • Custom water jet cut – they can be cut from a variety of materials to the precise size and thickness you need

NEMA / UL 50 Enclosure Gaskets

Technically there aren’t any NEMA gaskets since the enclosure is evaluated as a whole, but there are gaskets and gasket materials that will help an enclosure pass a specified test.

NEMA / UL 50 Type


Common Material Types

Type 1

Basic, indoor enclosures, protects from dust and falling dirt

Open cell or closed cell foams, closed cell sponges

Type 2

Indoor enclosure, protects against dust and falling dirt as well as dripping / light splashing of water

Fine pitched open cell (microsellular) foams or closed cell foams, closed cell sponges

Type 3

Indoor / outdoor enclosure, protects against windblown dust and falling dirt. Also protects against water (rain, sleet, snow and effects of ice formation)

Closed cell foams or closed cell sponges

Type 4

Indoor / outdoor enclosure, protects against windblown dust and falling dirt. Also protects against water (rain, sleet, snow, splashing water and hose directed water and effects of ice formation)

Closed cell foams or closed cell sponges

Type 5

Indoor / outdoor enclosure, protects against falling dirt, settling airborne dust, lint, fibers and flying debris. Also protects against water (rain, sleet, snow, splashing water and hose directed water and effects of ice formation)

Closed cell foams or closed cell sponges

Type 6

Indoor / outdoor enclosure, protects against falling dirt. Also protects against water (hose directed water and the entry of water during prolonged submersion at a limited depth and effects of ice formation)

Closed cell foams, closed cell sponges, low and mid durometer solid elastomers

Type 12

Indoor enclosure (w/o knockouts, 12K w/ knockouts), protects against falling dirt, settling airborne dust, lint, fibers and flyings. Also protects against water (dripping and light splashing)

Fine pitched open cell (microcelluar) foams or closed cell foams, closed cell sponges

Type 13

Indoor enclosure, protects against falling dirt, settling airborne dust, lint, fibers and flying debris. Also protects against water (dripping and light splashing). Some protection against spraying / splashing / seepage of oil and coolants

Chemical compatible closed cell sponge

IP Enclosure Gaskets

The intentions of the IP code are similar to NEMA and UL. The first digit (IP 6X) refers to solid particle. The second digit (IP X1) refers to water. For example, IP%$ refers to an electronic enclosure capable of sealing out dust, water and protect against vertically dripping water.

IP Spec

1st Digit

2nd Digit

Common Material Types


5 Protect from dust and water, some dust ingress allowed but not to interfere with function

3 Protect from spraying water (angle up to 60 from vertical)

Closed cell foams, closed cell sponges, microcellular foams


6 Completely protected from dust and water ingress

3 Protect from spraying water (angle up to 60 from vertical)

Closed cell foams, closed cell sponges, microcellular foams


6 Completely protected from dust and water ingress

4 Protect from splashing water (from any direction)

Closed cell foams, closed cell sponges, solid rubber


6 Completely protected from dust and water ingress

5 Protect from pressure jets of water (from any direction)

Closed cell foams, closed cell sponges, solid rubber


6 Completely protected from dust and water ingress

6 Protect from strong pressure jets of water (from any direction)

Closed cell foams, closed cell sponges, solid rubber


6 Completely protected from dust and water ingress

7 Protect while temporarily submerged (up to 1 meter)

Solid rubber

EMI Enclosure Gaskets

Commercial applications, not held to military specifications, typically yse nicel graphite filled silicone. The Nickel particles are mixed into silicone polymers and cured into conductive rubber sheets or rolls. Larger EMI gaskets can be made with strips or interlocking strips to maximize the yield.

For gaskets required to meet MIL-DTL-83528, the polymer and conductive fill are defined by specification types:

  • Type A – silver coated copper + silicone (65 durometer)
  • Type B – silver coated aluminum + silicone (65 durometer)
  • Type C – silver coated copper + flurosilicone (75 durometer)
  • Type D – silver coated aluminum + fluorosilicone (70 durometer)
  • Type M – silver coated glass + silicone (65 duromater)

Keep your electronics interference-free

At A&J we use a .140 diameter tubular gasket (210-1130) that is added to the extrusion grooves and consists of a silicone inner core that is plated with silver / aluminum for the seams between the frame members that are joined together.

Our enclosures are attenuated to 60 DB from 150 Hz to 1 million Hz and 40 DB from 1-2 million Hz in accordance with MIL-STD-461G for EMI/RFI shielding. Our team of professionals can help you determine the type of shielding your rack or enclosure needs and install it quickly and efficiently. Contact us today!

Optimal Airflow in Electronic Enclosures; and 4 Design Tips

Thermal management for sophisticated electronics in protective enclosures starts with one fundamental element: airflow. Optimal airflow in electronic enclosures, both within and throughout, can mean the difference between successfully maintaining and cooling your sensitive components and risking costly downtime associated with failures.

Equipment has specific operating temperature ranges and when put inside of cabinets and enclosures, temperature can become a big issue. Cooling should be considered early in the design process, but having an effective cooling strategy can help in adequately dealing with heat dissipation.

First: Understanding Heat Transfer

Heat transfer takes place in three ways: through radiation, conduction and natural or forced convection.

Heat transfer via radiation occurs through electromagnetic waves, similar to the sun’s energy reaching the earth.

Heat can also be transferred through conduction between objects. A common example of this is a microprocessor chip cooled using a heat sink, making direct contact with the chip.

Most systems remove heat through a combination of methods. Going back to the microprocessor chip, it may be cooled using a heat sink (conduction) that includes a fan (forced convection).

The most commonly used cooling methods for enclosures, in order of increasing cost, are natural convection, forced convection and air conditioning.

Second: Understanding Airflow

Natural Convection

This is the most basic form of airflow. When heat rises, cold air is pushed to the bottom of a space. If convection isn’t properly addressed, a hot spot will form at the top of the enclosure.

Natural convection cooling is adequate for most applications that generate mild heat. But, an easy solution is passive ventilation, or louvres.

Louvres are open, unfiltered vents positioned to allow ambient air to be drawn into the enclosure through openings positioned low on the enclosure surface, and to exit through similar openings positioned high on the same surface. They’re also a popular option because they provide some protection against dust entry.

Forced Convection

Using the same principles as described above with natural convection, forced convection adds a fan, blower or compressed air to force the warmed air through the enclosure and out through the upper vent.

Three devices are commonly used: fans, blowers and fan trays

Axial fans are typically capable of delivering high volumes of air at medium to low pressure

Blowers, or centrifugal fans, change the direction of the air, typically 90 degrees, and push the air out through a ducted system. They offer higher pressure with a lower flow.

Fan trays are used to direct airflow to hot spots when there is restricted airflow due to servers, drawers or shelves. It’s basically a chassis with a fan cooling module that can be mounted directly below the sensitive equipment or a hot spot. At A&J we’ve created a separate sub assembly that support fans with related parts such as EMI and dust filters.

Air Conditioning

For critical and thermally sensitive applications, or sealed cabinets, air conditioners provide the greatest capacity to transfer heat. Most air-conditioned cabinets are sealed with only inside air circulated inside to prevent moist air from entering and causing condensation.

Basic Airflow Calculations

For For ∆T in degrees F: Airflow (ft3/min) = BTU/hr / (1.08 × ∆ΤF) = (3170 × kW) / ∆ΤF

For ∆T in degrees C: Airflow (ft3/min) = BTU/hr / (1.95 × ∆ΤC) = (1760 × kW) / ∆Τc

Typical values for ∆Τ are 10C and 18F. Add 25 percent for a safety margin (12.5C and 23F). Note that ∆Τ represents the temperature rise over ambient air temperature. If ambient is too high, it may be difficult or impossible to maintain a safe operating temperature without air conditioning.

Airflow Calculator

Design Tips for Component Placement

  • Components with significant heat generation should be given extra space to exhaust the heat and allow for proper airflow around them. Place these items closer to the intake of the AC, if using.
  • Components that run cooler can be stacked closer together. Airlfow is less of a requirement with these pieces because they have minimal effect on overall heat within the enclosure.
  • There should be clearance to walls and doors; keeping the hotter components away from walls of the enclosure allows for better circulation of air within the space.
  • When a component has an active airflow through internal fans, directing the airflow towards the AC intakes will help the cooler to perform more efficiently. It is more beneficial to get the hot air from the equipment into the AC, than it is to get the cold from the AC to the equipment.
  • Special consideration should be made when components have internal fans mounted on its front panel. It is common to recess the front retma bars and/or specify a deeper door to ensure proper airflow facing the front of the rack.

Thermal Management Solutions to Consider

When planning your next project design, consider these three solutions:

  1. Fans – one of the oldest solutions to help boost natural ventilation. An air filter should always be used to minimize dust and debris, but ensure that the free-airflow rate (CFM) is three times grater than the calculated flow rate.
  2. Enclosure air conditioners – a viable option when the capacity requires over 1000 BTUH and especially beneficial if you’re operating in an environment that has wide temperature fluctuations.
  3. Air to air heat exchangers – a low-energy and low-maintenance solution that uses a heat pipe to absorb the heat inside the enclosure and transfer it to the outside via a phase-changing liquid under vacuum. However, it requires that the ambient air outside the enclosure be lower than the air inside.

We’re committed to helping you get the most out of our enclosure cooling options

Discuss your specific requirements with our engineers to get the most cost effective solution for your cooling needs. Get more information about configuration and placement from our experts.

EMI / RFI shielding: what it does and why it’s important

EMI, or electromagnetic interference, and RFI, or radio-frequency interference, are both types of electromagnetic radiation. EMI is emitted by electronic devices and can interfere with the proper functioning of other electronic devices, while RFI is emitted by radio waves and can interfere with radio signals.

EMI and RFI shielding is a process of enclosing electronic devices in a material that absorbs or reflects electromagnetic radiation to protect the devices from interference.

It can prevent everything from minor crackling during broadcasting to deadly malfunctions in aircraft safety equipment. If left unmitigated, it can disrupt the essential functions of electronic devices or erase or damage data. Even satellites in space need to be shielded from EMI/FRI to function properly.

Common sources of EMI/RFI include cell phones, microwaves, power lines and computer circuits. There are all natural causes of these signals such as auroras, solar flares or lightning.

EMI / RFI shielding

What is EMI / RFI shielding, and what does it do?

EMI/RFI shielding is a process or material used to protect electronic equipment from EMI and RFI. EMI/RFI shielding can protect against various sources, including radio waves, microwaves, and electrical currents.

EMI/RFI shielding creates a barrier between the electronic equipment and the source of interference. This barrier can be made with a variety of materials.

Materials used for EMI/RFI shielding

For EMI/RFI shielding, a variety of materials can be employed. The following are the most frequent materials:

  • Metals
  • Conductive plastics
  • Carbon-loaded plastics
  • Conductive coatings
  • Metal mesh

Metals are the most common material used for EMI/RFI shielding. They are effective because they reflect and absorb electromagnetic radiation.

Importance of EMI / RFI shielding in electronic devices

EMI/RFI shielding is essential in electronic devices because it can help to reduce or eliminate interference that can lead to errors, data loss, and equipment damage. Shielding can also help improve electronic device performance by reducing interference from outside sources.

EMI/RFI shielding creates a barrier between the electronic equipment and the source of interference. This barrier is produced with various materials, including metals, conductive plastics, and special coatings.

How to choose the right EMI / RFI shielding for your needs

When choosing EMI/RFI shielding for your electronic devices, it is vital to consider the type of interference you are trying to protect against, the level of protection you need, and the environment in which the electronic devices will be used.

Some EMI/RFI shielding types, such as metal shielding, can block a wide range of frequencies. However, metal shielding can also block signals you may want to receive, such as radio waves. In addition, metal shielding can interfere with the proper functioning of some electronic devices.

Other EMI/RFI shielding types, such as conductive plastics and special coatings, can be customized to block specific frequencies while allowing others to pass through. These materials can also be used in various environments, including wet or humid ones.

Common applications for EMI / RFI shielding

EMI/RFI shielding is used in a variety of industries, including:

  • Automotive
  • Aerospace
  • Telecommunications
  • Medical
  • Mass transit systems
  • Navigation and vehicular control systems

Keep your electronics interference-free

If you’re looking for ways to protect your electronic devices from interference, look no further than EMI and RFI shielding. Enclosed devices in a material designed to absorb or reflect electromagnetic radiation to keep them functioning correctly. At A&J we use a .140 diameter tubular gasket (210-1130) that is added to the extrusion grooves and consists of a silicone inner core that is plated with silver / aluminum for the seams between the frame members that are joined together.

Our enclosures are attenuated to 60 DB from 150 Hz to 1 million Hz and 40 DB from 1-2 million Hz in accordance with MIL-STD-461G for EMI/RFI shielding. Our team of professionals can help you determine the type of shielding your rack or enclosure needs and install it quickly and efficiently. Contact us today!

Rack Mounting Options for your Electronic Equipment

A rack mount is a description of a hardware device capable of being mounted in an equipment rack. All types of electronics and computing devices come in rack-mounted packages including servers, test instruments, telecommunications components, which are bolted to the side frames of the rack. Note: shelves are available for equipment that is not rack mounted.

Measuring cabinet dimensions, specifically depth

Before ultimately choosing a rack mounting option, let’s first review how to properly measure your rack space. As a reminder, cabinets or enclosures are traditionally referred to by their external dimensions. But in most cases, the rack depth is 4 to 6 inches less than the external cabinet depth.

To measure the rack depth, measure the distance between the forward-most part of the front rail to the rear-most point of the rear rail. A&J typically recommends 34 in. (86.36 cm) or greater cabinets for use with equipment that have an average depth of 28 in. (71.12 cm). The 6 inches (15.24 cm) at the back between the equipment and the back door or panel allows for cable management, airflow and maintenance access.

Equipment mounting options

Originally mounting holes were tapped with a particular screw thread, but has since become problematic where equipment is frequently changed because the threads are easily damaged or the mounting screws can break off. Both problems render the mounting hole unusable.

Tapped-holes were then replaced by clearance-hole racks. Holes are large enough to permit a bolt without binding and fastened in place using cage nuts.

The third innovation has been square-hole racks. These racks allow boltless mounting where the weight of the equipment and small retention clips are all that is necessary to hold equipment in place.

The structural support

A key structural weakness of front-mounted support is the bending stress placed on the both the rack itself and the mounting brackets of the equipment. Our A&J racks can incorporate front and rear rails that may be moved forwards and backwards that allows equipment to be supported by four posts, but also easily installed and/or removed.

Our standard AJR 150 Series 4-post racks are 22.31″ (566.6 mm) wide with three depths: 26″, 30″, 36″ (660.4 mm to 914.4 mm). The extra width and depth enables cabling to be routed with ease and deeper equipment to be installed. It can also accommodate “Zero-U” accessories such as PDUs and vertical cable managers in the space between the rear rails and the side of the enclosure.

Rails (slides)

Often used for heavy equipment that requires regular servicing, a pair of rails can be mounted directly onto the rack which allows the component to slide into the rack along the rails. The equipment can then be bolted to the rack (as described above) or the rails may also be able to fully support the equipment in a position where it has been slid clear of the rack. Consider purchasing a cable management arm, which folds the cables attached to the server or component and allows them to expand neatly when the rail is slid out, without being disconnected.

Tools required

You will need some of the following tools to rackmount your equipment:

  • Philips No. 1, No. 2, and No. 3 screwdrivers
  • Flat-blade No. 1 and No. 2 screwdrivers
  • Allen and adjustable wrenches
  • Needlenose pliers
  • Level
  • Electrostatic discharge (ESD) wrist strap
  • ESD mat

Rack Mounting Tips & Guidelines

  • Install the heaviest equipment and storage devices in the lowest position in the rack to prevent the rack from becoming too-heavy and prone to tipping over.
  •  Install any remaining equipment from the lowest system upward into the rack.
  • For applications that require high-density cabling, you may need 1U of horizontal cable management for every 1U of patch panels or switches.
  • Ensure the rack is properly secured to the floor or ceiling and level before installing any components.

Benefits of a Modular Enclosure

Because the Industrial Internet of Things (IIOT) has accelerated the evolution of industrial engineering, it’s generally a good idea to err on the side of versatility. But there are several misconceptions or misunderstandings about the traits and attributes of a modular enclosure. A fully realized modular enclosure will help you respond better to market demands, supply chain logistics and other variant-rich environments with greater flexibility, agility and speed.

What a Modular Enclosure Is and Isn’t

There are specifically three terms that are used incorrectly.

Unibody Enclosure – Often constructed with welded steel or other heavy sheet metal, their rigid design can hamper maintenance, repair or modification of the enclosure and the equipment within it.

Modified Enclosure – While a modified enclosure can have some of the same traits as a modular enclosure, it simply encompasses an enclosure with custom holes or tapping

Modular Enclosure – an industrial enclosure with accessories or panels that can easily be reconfigured or rearranged within its standard frame. It virtually eliminates costly machining and fabrication as your device components change.

Benefits of a Modular Enclosure

  1. Infinite configurations – Modular frames come with pre-drilled holes using the EIA’s standardized unit of measurement. And common accessories or network devices can be added to the interior without additional drilling or welding. Plus, these frames can easily be bayed together to create nearly infinite configurations.
  2. Faster mounting & installation – Using rails, an integrator can easily slide panels into or out of the front, side or rear openings of an enclosure. Mounting becomes easier and faster when compared to the unibody technique of laying an enclosure on its back and lifting the panel with a forklift or crane. This all adds up to saving you time and money.
  3. Built to last – Due to its vertical framing, a modular cabinet won’t lose any of its strength or protective qualities.
  4. Flexibility – A designer, integrator, engineer and end user each have the freedom to make assemblies as basic or as complex as a job requires. Again, components can be arranged without the need to cut or weld. This allows for varied and unique configurations inside, while also allowing flexible cable or maintenance entry. Any enclosure can be adapted to meet your  needs.
  5. Maximizes floor space – Space is a premium and all floor designers / engineers want to maximize the square-footage at their disposal. Modular enclosures can be customized or tailored to fit specific applications in a variety of environments. They unlock efficiencies and flexibility though both inner and outer mounting levels, multiple baying opportunities and accommodate a variety of connection configurations.

Core Elements of a Modular Enclosure

The prime characteristics of a modular enclosure include:

  1. Protection of enclosed devices / equipment – There are several physical stressors present in any given environment: tampering, water, mold, corrosion. And just like traditional unibody designs, a modular enclosure can be certified to rugged industry standards (MIL-S-901D, NEMA). Properly assess local weather conditions, corrosive substances and even resistance levels of internal components.
  2. Compartmentalization – A modular design allows you to compartmentalize separate pieces of IT equipment or add thermal accessories to help with climate control. It removes the need to source several cabinets or climate-control systems. It also saves floor space!
  3. Ease of modification – It’s easier to scale up or scale down manufacturing needs based on production sequence, customer demand, space or other factors with a modular design. And users can easily swap parts out for new ones and modify panels.
  4. Mounting panels – The most commonly modified part of any enclosure, the mounting panel in a modular design allows for the addition of rails, making it possible to slide the panel into and out of the front, side or rear openings. It eliminates the need to lay the enclosure on its back and lifting the panel with a crane or forklift.
  5. Availability of sizes and types – While available in traditional sizes, it can also be configured to specific applications with full size or partial doors, multiple mounting panels and entry points.

Thinking About a Custom Rack Design? Here’s What to Consider

Racks help organize IT equipment into more collective assemblies that free up space and make efficient use of resources. A rack typically consists of two or four vertical rails for mounting, along with a supporting framework that secures the rails. Both the framework and rails tend to feature aluminum or steel construction, which makes them capable of supporting up to thousands of pounds of IT equipment. The rails also include round or square holes that make it easy to use screws for mounting rack equipment.

If standard rack designs don’t work for your application, you may benefit from a custom server rack. When creating your custom rack design, there are many key factors to consider to ensure the best possible rack for your needs.


Things to Consider with Custom Racks & Enclosures

When in the market for a custom electronic rack, there are certain items to consider to inform your design.

One element that will go into a custom rack design is the desired size. Obviously all of your electronic components need to fit comfortably inside, but you also need to consider the space between them to avoid interference. Your rack or enclosure should also accommodate the necessary space needed for maintenance and device assembly or installation.

Regarding external size dimensions, the primary limitation is that the bend radius must not be less than the enclosure material’s thickness. Through CNC machining, we can manufacture enclosures as small as 11.75″ x 16.5″ x 9.5″. We encourage you to contact us about your design to discuss it further with our design engineering team.

Depending on the application, you’ll need to account for any industry standards or ratings that enclosures must meet to protect equipment from dust or water. For instance, equipment may need to meet NEMA and military standards or have an IP rating.

Consider the different accessories available to you, which could include:

  • Cooling — Blowers, fans, and fan trays
  • Power Management — Cable support, distribution, and power strips
  • Internal Slide Hardware — Slide brackets and mounting brackets
  • External Panels & Hardware — Blank panels, nuts, screws, and washers
  • Shelves & Drawers — Sliding and fixed shelves and sliding drawers
  • Shock, Vibration, and Seismic Resistance — Open-frame racks and enclosure racks
  • Secure Racks — Blanking panels

Standard Options vs. Custom Design

Oftentimes, you may not need a custom rack cabinet if you can benefit from using standard equipment, which is why this is one of the first determinations to make. Customers may also be able to fit a stock enclosure with various custom features instead of designing an entire custom rack, saving more time and resources.

A&J’s racks are modular, which makes them easy to adapt to various hardware and technology.

Other factors to consider include:

  • Expandability. At A&J, our kits allow us to gang cabinets together to form a “suite,” which helps increase stability and enables easier management of interconnecting cables.
  • Accessibility. Our cabinets’ bolted-together design makes it easy to remove side panels from the exterior, allowing easy access to interior cabling and components.
  • Cable Management. Most equipment on a rack requires cabling for operational or network connectivity purposes. Our cable management accessories offer a key solution in these situations.

Benefits of Custom Enclosures from A&J

A&J’s custom enclosures offer the following advantages:

Lower Upfront Costs
Although you can create custom enclosures in-house, it can be very costly to invest in the required equipment, manufacturing tools, and materials. This equipment can take up a lot of space in your facility and may require lots of trial and error to produce an effective enclosure. Our expertise at A&J can help you avoid these challenges, saving you time and money.

Greater Process Knowledge
Our engineers possess the necessary techniques and expertise to drill into aluminum rack materials without causing any damage.

Lower Labor Costs
When creating custom racks in-house, your staff may have less time to focus on primary goals. It will also make employees work beyond their expertise, leading to reduced productivity. A&J will help reduce labor costs by enabling your staff to spend more time on the tasks they can effectively handle.

Customizing Your Enclosure with A&J

At A&J, we offer custom CNC machining to manufacture custom electronic racks. This allows for precise cuts, reduced scrap, and advanced capabilities. In addition, you’ll benefit from engineering support as well as a wide selection of standard rack sizes and models with accessories that we can easily modify to suit different applications.

To order a custom or standard rack, you can take the following steps:

  1. Browse our selection of standard rack enclosures and accessories to locate the ideal choice
  2. Submit a quote with basic specifications
  3. Upload a drawing, ideally a CAD drawing, for our engineering team to review, or we can draft an initial design with the help of our design engineering services
  4. Place your order, and we’ll ship your rack to the designated final destination

Get in Touch with A&J Today

Want to get started on selecting or designing an electronic rack for your application? Request a quote or talk to an engineer today.

Understanding the Components of an Electronic Enclosure

Today, virtually all businesses rely heavily on technology to satisfy their customers, regardless of size. And with these technological advances, we’re starting to place electrical equipment in a variety of nontraditional environments. To ensure proper protection of electrical components, choosing the right electrical enclosure for the application at hand is critical. But first, let’s break down the basic components of an electronic rack.

The Structure of an Electronic Enclosure

Generally tall and rectangular in shape, an enclosure is typically made up of a two- or four-post rack mainframe and mounting rails. Depending on the design, some enclosures have rear and/or front doors, side panels, top panels and bases. Enclosures are highly customizable and various components or areas of the rack can be modified to fit a customer’s needs or environment. If you’ve never seen one outside of a data center or other industrial function, they could easily be mistaken for an extra large filing cabinet.

The terms cabinet and rack are often used interchangeably; however, that would be incorrect. As described above, racks are simply the frame inside a cabinet that is used for mounting all of the electronic equipment. Cabinets enclose a rack and include all of the necessary connections for electrical power, cooling fans for thermal management, and EMI / RFI shielding capabilities. Cabinets themselves come in a wide variety of sizes and colors.

Again, because the two terms are often used conversely, there’s often confusion about how to measure dimensions properly. Cabinets are traditionally measured by their external dimensions while racks are measured from the most-forward portion of the front rail to the rear-most point of the rear rail. We typically recommend at least 6 inches between components and the rear cabinet door to accommodate cable management, airflow and necessary service access to components.

Rack widths are specified by EIA 310D standards and include 19″, 23″, 24″ and 30″ inches. With racks you also need to be mindful of your vertical spacing for all equipment that you plan to mount in your enclosure. EIA 310D-compliant define one rack unit (RU) as 1.75 inches with three mounting holes spaced at 5/8, 5/8 and 1/2 an inch apart.

Equipment Found in a Rack

The design of a rack is rather basic, but the vital equipment inside can process or store an immense amount of information. And military systems specifically often represent extreme environments for COTS electronic equipment. Typically, equipment found in racks support IT or datacomm equipment such as: servers, network switches, GPS and navigation systems and telecommunication routers/hardware. However, there are several industrial applications for cabinets and enclosures too: large-scale battery storage, test system components, and manufacturing or plant floor enclosures.

Equipment layout, whether isolation is required and how the electronics are mounted/”housed”, can vary widely. Racks also accommodate all the accessories that support the equipment itself like PDUs, cable management, patch panels, shelves and drawers, and thermal management systems.

When you’re able to demystify the necessary components and even the basic structure of an electronic enclosure rack, you can more easily identify the features you need. For more information on the products we offer, please contact A&J Manufacturing today or browse our Frequently Asked Questions.

Get Those Wires Organized: Rack-Mounted Cable Management Accessories

Among some of the most frequently forgotten, yet necessary components of any rack solution are cable managers. Cables are often difficult to incorporate into 3D CAD drawings and since they’re “out of sight, out of mind”, the accessories needed to organize them are also forgotten. But nearly every piece of equipment in your rack requires data cables to provide network connectivity, or at the very least, power cables to make them operable.

Top Cable Management Accessories for your Electronic Rack

With an open-frame rack, we typically recommend vertical cable managers that span the full height of the rack, but they aren’t as commonly used in cabinets or racks with side panels. Instead, consider using vertical cable rings to keep cables organized and prevent them from blocking access to your electronic equipment. To minimize electromagnetic interference (EMI), our design engineers recommend running the rings down the rear rails with all cable powers being routed through the rings on one side and data cables running down the opposite length. 

If your rack will house any high-port equipment, the ideal solution is to position horizontal cable managers both above and below the equipment to improve access to both rows of cables and reduce the potential for accidental disconnects. 

And even if you don’t use any specific cable management accessories, basic hook and loop cable ties are fundamental to organization. We don’t recommend using zip ties since they will eventually need to be cut and could compromise the cables themselves risking damage and causing waste.

Rail Depth

One of the most critical considerations to keep in mind when choosing the appropriate cable management solution for your cabinet is the impact they can have on rail depth. A&J offers three standard rack depths: 19″, 24″ and 30″, but we can also create any custom depth required. Without enough clearance space, the mass of wiring can obstruct airflow and/or the rear panel.

Tips to Make Cable Management Easier

  1. Measure connection distance between components so you’re not wasting money or space on excess cables. Most electronics vendors offer a variety of power cord options or you can purchase your own low-profile power cords to free up additional space.
  2. Proper, well-planned cable markings will simplify any troubleshooting and changes without unnecessary work within the rack. And if you color code your cables this will help differentiate different types of cables. We also recommend labeling both ends so you know exactly where they go and what they’re being used for.
  3. Cable management arms neaten up a rack, but you might also need to consider reducing the server count in a rack to free up space or design a deeper model for adequate clearance.
  4. Carefully plan and execute the cable trunk to avoid obstructions to ventilation and cooling airflow. The last thing you want is running it along a series of servers directly behind their exhaust fans.
  5. ALWAYS confirm how the rack’s overall dimensions fit within your existing floor plan to avoid disruptions to aisle containment or waste IT staff time during setup in a tightly configured layout.

How to Choose the Right Metal Finishing Options for your Custom Electronic Enclosure

Just like electronic equipment rack designs and accessories, the end use for your product determines the best type of metal finishing option to use for your custom electronic enclosure or rack. Finishes provide a durable coating that protects a product from its environment and function best. Does your enclosure need to be able to withstand high temperatures? Avoid corrosion? Promote electrical conductivity?

Frankly, cost and production time are less important factors. You want the best results possible! Read on to determine which metal finishing option is best for your electronic enclosure.

Metal Finishing Option: Bare Metal Finishes

There are three options: “no finish”, “grained finish” and “tumbled”.

About “No Finish/Natural”

Parts are de-burred with no additional finishing, but minor surface scratches and blemishes are to be expected. There’s no additional cost and best used for functional parts that won’t be on display.

About “Grained Finish”

Parts are de-burred, and then given a specific linear grain direction via brushing. It can only be applied to accessible flat exterior faces on machined parts and can also be digitally printed or silkscreened.

About “Tumbled Finish”

A great option for machined parts, but maximum size is 10x10x10. This process smooths and imparts non-directional finish via tumbling in abrasive medium. It can also be digitally printed or silkscreened.

Metal Finishing Option: Powder Coating

Powder coating is a dry finishing process in which free-flowing, thermoplastic or thermoset powder material, rather than a liquid suspension, is applied to a surface, melted, and then allowed to dry and harden into a protective coating. It provides a better, more durable finish than paint. It’s also highly effective in removing surface defects.


  • Durability
  • Thicker and specialty finishes available
  • Less environmental impact
  • Shorter curing, processing and drying times
  • Undamaged and uncontaminated powder overspray can be reclaimed and recycled for future applications (utilization rate is close to 100%)


  • Range of suitable materials is limited due to the fact that it must be heated to be cured
  • Difficultly producing thin coatings
  • Not cost-effective for custom, small batch coating needs
  • Curing and drying times increase for large, heavier parts (due to higher temperatures required)

Metal Finishing Option: Chemical Conversion Coating

Also known as Chem Film or chromate coating, this process applies chromate to a metal surface that is corrosion resistant, durable and exhibits stable electrical conductivity.

If you’re using your rack in a rugged environment, use a vendor that is MIL-DTL-5541F qualified. The standards include utilizing a process that doesn’t use toxic hexavalent chrome and has been replaced with the safer zirconium, titanium or trivalent chromium. It’s also been sufficiently tested against corrosion and proves to have reliable electrical conductivity.


  • Extends the service life of parts
  • Cost efficient and economical
  • Doesn’t change part dimensions


  • High energy demand

Metal Finishing Option: Anodizing

Anodizing is an electrochemical process that involves dipping aluminum into a bath of acid and passing an electric current through the medium. It converts the surface into a decorative, durable, corrosion-resistant oxide finish.

Anodized aluminum protects satellites from the harsh environment of space, and revolutionized the construction of computer hardware, scientific instruments and consumer products like kitchen appliances.


  • Durability – creates an extremely hard surface that is more resistant to scratches
  • Resistant to corrosion, heat and electricity
  • Low environmental impact – non-toxic finish with no harmful by-products


  • Limited color selection and its often subject to color variations
  • Requires a high-grade alloy of aluminum
  • Not cost effective for small quantities

Contact us today to learn more about the different types and colors of enclosures finishes that are available.