When a screen is being used outdoors for such purposes as outdoor digital signage, it is fairly obvious that it is going to need protecting from the weather. However, protecting a screen from outdoor elements is not as easy as it may sound, and several important factors need taking into consideration.
The first problem with weather protection for a TV screen is the need for screens to expel heat. If you look at the back of any TV device, you will see vents, designed so that hot air generated inside the television can get out. With LCDs most of the heat is generated by the backlight, and failure to allow this heat to escape will soon lead the screen to overheat, which can cause the screen to fail, permanently.
The difficulty in using a screen outdoors is that to prevent damage from rain and other weather elements the screen needs waterproofing. However, the screen can’t just be sealed inside a watertight enclosure because the heat generated by the TV still needs expelling.
To get around this, outdoor LCD enclosures have vents on the underside of the enclosure, and to prevent moisture splashes from getting inside they employ a clever chambering system that is shaped specifically to allow air out but no water in. Cooling fans inside the enclosure provide the necessary circulation of air that expels the heat and draws in cool, fresher air, ensuring the internal temperature remains at the optimum for running the screen.
These cooling fans also help in times of warm weather when overheating is even more of a problem. During summer and in hot locations the fans ensure the screen is kept within operating ranges—for some locations that experience extremely high levels of heat in the summer additional fans are required, and in some circumstances, air conditioners are employed.
In winter, the opposite problem can occur. If temperatures get too low and freezing occurs, this too can lead to permanent damage of the screen. To prevent this, the fans can be thermostatically controlled to make use of the heat generated for the screen to keep temperatures in the required range, while insulation and even heaters can be deployed for extremely cold weather locations.
