Selecting a suitable enclosure requires careful consideration of the application's specific requirements. Key factors include the operating environment, material properties, the space needed to accommodate the electronics, and any ergonomic or design requirements. The enclosure's form and design should also be considered, as they play a significant role in shaping the appearance and overall perception of the finished product.
A systematic evaluation of these criteria helps to identify the most suitable enclosure options. Another important consideration is whether the electronics have already been developed or whether the enclosure will serve as the starting point for the product design. Ideally, the enclosure should be incorporated into the design process from the outset, allowing the available installation space to be used efficiently and minimising the need for costly modifications later in development.
1. Size of the electronics
• Length, width and height of the circuit board(s).
• Space required for connectors, control elements, cable inlets and outlets, displays, control elements and LEDs.
• How is power supplied? Externally via a power cable or internally using batteries/rechargeable batteries.
• Additional reserve space within the installation area for future expansions (10–20 % is often advisable).
2. Operating environment
Where will the device typically be used? This determines, for example, the required protection rating (IP rating) and the type of plastic used.
• Indoors or outdoors?
• Is the device exposed to direct UV radiation?
• Are temperatures particularly high or low?
• Is the environment dusty or exceptionally humid?
• Is the device subject to regular vibrations or impacts?
• Does the product come into contact with chemicals or salt water?
• Are aggressive cleaning agents used, or are these even required by a standard?
3. Material
Enclosures are generally available in three different materials, each with its own advantages and disadvantages. These should be compared to find the optimal solution for the final device.
• Plastic (ABS, polycarbonate, etc.): lightweight, cost-effective, electrically insulating.
• Aluminium: robust, good heat dissipation and EMC shielding.
• Stainless steel: for particularly demanding or corrosive environments.
OKW enclosures are manufactured from high-quality, single-grade plastic materials sourced from reputable manufacturers. You can download a quick overview here.
Our products comply with the requirements of environmental directives and regulations such as REACH, RoHS, WEEE, etc. A summary of the relevant substances.
4. Heat generation
The more powerful the electronics become and the more components are installed in a very small space, the higher the heat generation.
• Is passive cooling sufficient for heat dissipation?
• Are ventilation slots required, or must cooling be provided via separate heat sink elements or fan units?
• Should the enclosure itself serve as a heat sink?
5. Technology and accessories
Where will the device be used later, and are there already suitable accessories available for this?
• Wall brackets for concealed or permanently accessible wall mounting
• simple mounting on DIN rails, e.g. in a control cabinet or in small distribution boards
• non-slip use as a desktop unit
• portable unit with a shoulder strap/webbing, clip, charging station, etc.
A wide range of accessories to suit the various product families
6. Connections and operation
The housing should allow for the easy integration of components. Ideally, flat surfaces should be provided for this purpose, which significantly simplifies mechanical machining for drill holes or cut-outs and the assembly of components, e.g. for:
• USB, Ethernet or other connectors
• displays
• LEDs
• pushbuttons, switches, rotary controls, etc.
• antennas
• cable glands
7. Protection rating (IP)
IP protection ratings (Ingress Protection, IP code) indicate how well an enclosure is protected against the ingress of foreign objects, dust and water.
The letters IP, which are always present in the protection rating designation, are followed by two digits (generally without a space) (format: IPXY). These indicate the level of protection provided by an enclosure:
• X = Protection against contact and solid foreign objects (0–6)
• Y = Protection against moisture and water (0–9K)
Protection ratings and their meanings:
• IP20 = Protection against solid foreign objects > 12.5 mm, no protection against water
• IP44 = Protection against solid foreign objects > 1 mm, protection against splashing water
• IP54 = Dust-protected, protection against splashing water
• IP55 = Dust-protected, protection against water jets
• IP65 = Dust-tight, protection against water jets
• IP66 = Dust-tight, protection against powerful water jets
• IP67 = Dust-tight, protection against temporary immersion in water
• IP68 = Dust-tight, protection against continuous immersion
• IP69K = Dust-tight, protection against high-pressure/steam jet cleaning
Robust enclosures from OKW with high IP protection ratings
Information on IP protection ratings for OKW enclosures:
The IP ratings specified for OKW enclosures apply to standard products in their unmodified state, without any machining or additional accessories. As the final application and operating conditions are beyond our control, compliance with the stated IP rating cannot be guaranteed once the enclosure has been modified or integrated into an end product, particularly in outdoor environments where conditions may vary considerably. Furthermore, standard IP tests do not take account of product ageing, wear, or subsequent modifications. To ensure the required level of protection under actual operating conditions, we therefore recommend testing and certifying the finished end product.
Here you can downloar information material concerning the protection classes of OKW enclosures:
OKW_Protection_Classes.pdf
8. EMC requirements
If an electronic device generates electromagnetic interference or is sensitive to external sources of interference, effective EMC shielding is required to ensure reliable operation. It is also necessary to meet EMC compliance requirements.
• Selection of a metal enclosure or
• plastic enclosure with an internal aluminium EMC coating
Coated plastic enclosures (blog article EMC protection)
9. Quantity and production
• Single unit/prototypes:
Standard enclosures or those available from stock in quantities of 1 or more are generally the most cost-effective solution
in this case.
• Small production runs:
Standard enclosures with customised finishing (drilling, milling, printing) are ideally suited to small to medium production runs.
• Large-scale production:
For developers, the choice between standard enclosures and a bespoke enclosure solution is largely determined by the project
requirements. Is it worth investing in dedicated injection moulding tools? At what production volume does this become
cost-effective? How long can the development period be? These factors should be assessed in a cost-benefit analysis
before the project begins.
BLOG-Article: Standard enclosure or customised solution: What attracts developers?