Posted by: Richard Williams | Posted on: | 1 Comments
Using screens outside, whether it is for outdoor digital signage, information provision or for providing entertainment, will require some form of weatherproofing. Using any electrical appliance outdoors can only be done safely and reliably if the screen is protected from the weather—particularly from water.
Waterproofing outdoor screens is essential because of the ability of water to instantly disable an electrical device such as a modern LCD or plasma screen. Even small amounts of water can cause short circuiting and lead to permanent failure—ruining the device and leading to a costly replacement.
Waterproofing a screen is not as simple as you may first think, however, as modern screens, whether they are plasma or LCD, need to ‘breath.’ Modern screens generate an awful amount of heat. Normally this is dispersed though the vents, ensuring the device doesn’t overheat, however, if the screen is housed in a waterproof TV enclosure then the problems arise.
Obviously to be waterproof, any protective enclosure can’t allow water to seep in, but then this leaves the quandary of how to let the heat escape. Secondly, air flow is necessary through the enclosure, not just to prevent overheating but also to prevent the screen steaming up and condensation from building up inside the enclosure.
Designing an enclosure for waterproofing outdoor screens is therefore a complicated affair. Any protective housing has not only got to be waterproof but also have some facility to allow fresh air in, and heated air to escape.
A variety of different approaches at this can be used varying from positive pressure systems, shaped air chambers, and sophisticated filtering systems. One commonality with waterproof enclosures, however, are the guidelines that they are built to.
Two different rating systems are used to describe the waterproof abilities of TV enclosures, the European IP rating which commonly denotes a waterproof enclosure as IP54 or IP65, or the NEMA system (USA—National Electrical Manufacturers Association), which commonly denotes a waterproof enclosure as being built to NEMA 4.