Feature sponsored by
ENCLOSURES How to specify plastic enclosures for HVAC,
climate and environmental electronics It’s no surprise that HVAC, climate and environmental technology can face a hard life outdoors. Bad weather can soon take its toll. But what’s not so obvious is the punishment that indoors settings can mete out.
T
emperatures can fluctuate significantly in ‘backstage’ plant rooms, duct spaces and basements. Hot relays, power supplies and processors can create microclimates inside enclosures. Condensation can form if the housing is sealed but not pressure equalised.
Then there are airborne dust particles, fibres and spores. Over time, they can damage electronics in or near ductwork, filters, fans and blowers. Filtration systems and air quality control units can be especially vulnerable. Invasive fine particles can build up conductive paths across PCB traces.
In commercial or industrial settings, equipment may be cleaned aggressively with solvents and detergents. Airborne chemical vapours can attack plastics, seals and coatings. Near-window installations expose devices to damaging UV rays, causing some plastics to discolour and become brittle.
PCB solder joints, connectors and internal mounting points suffer fatigue if enclosures are not designed properly.
EMI/RFI can also be an issue. HVAC systems are full of high-current motors, compressors and switching relays that can generate EMI. Wireless devices can suffer communications dropouts, data corruption or even full hardware failure if not shielded. And it’s not just HVAC electronics at risk. Climate change is creating demand for more applications, including wind turbine controllers, air quality meters, Geiger counters, agricultural climate control systems, inspection cameras and leak detection.
For indoor systems, an ingress protection rating of IP 54 to IP 65 is often sufficient to protect against dust and splashes. For outdoor systems, greater protection is needed – typically IP 66.
ABS has long been a popular plastic for enclosures but HVAC, climate and environmental applications often call for something tougher such as UV-stable ASA+PC or robust PC+ABS.
EMC shielding is also critical. An all-too-
easy mistake is believing that, because a device performs well in a laboratory environment, it will do so in situ. But this ignores the large electromagnetic fields generated by HVAC motors, compressors or rooftop communications arrays. For IIoT integration, enclosures must accommodate external antenna mounts, sealed cable glands and interfaces such as LEDs or touchscreens without compromising environmental protection. Failing to plan properly for external connectivity can result in water ingress around poorly fitted connectors. Best practices include using IP 68 cable glands and gasketed viewing windows for displays.
Wall-mount and pole-mount enclosures for outdoor environmental electronics must be extremely tough and weatherproof. OKW’s rugged SOLID-BOX (IP 66, IP 67) is rated IK 08 for impact protection. It can be installed ‘lid closed’ to protect the electronics. All the fixings are concealed beneath snap-on trims. Deep recesses on the long sides help to protect connectors. Alternatives to SOLID-BOX include ROBUST- BOX (IP 66). Its different tops and bases can be combined to create a wide choice of sizes. Like SOLID-BOX, it too has trims to
conceal the fixings.
IN-BOX (IP 66, IP 67) is a cost-effective housing for terminal installations. It is available in ABS (IK 07) and PC (IK 08). Variants include a transparent lid. Accessories include pressure equalisation elements, security kits, internal hinges, mounting plates and DIN rails. Slim, stylish NET-BOX (IP 65) has a curved top and a front lid that conceals connectors and interfaces. Optional infill covers close the underside, creating extra space. Low-profile DIATEC has a central control panel for a touch screen, display or keypad. A recessed area protects interfaces, cable glands and plug-in connectors. Accessories include wall suspension elements and a slot-in panel.
MINI-DATA-BOX (IP 65) and EASYTEC (IP 65) both feature flanges for quick and easy mounting with screws or cable ties. MINI- DATA-BOX can also be specified without these flanges. Both ranges are moulded from UV-stable ASA+PC (UL 94 V-0). For more information, view the OKW website:
https://www.okw.co.uk/en/news/ blog/BLG2507-enclosures-for-hvac-
environmental-electronics.htm
OCTOBER 2025 | ELECTRONICS FOR ENGINEERS
27
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42
