Is it true that touch screen keypads fail in warm weather and have a shorter life than the older style mechanical keypads – what’s the best option in your opinion?
A: The most robust keypads are going to be stainless steel, IP67-rated against weather and IK10 rated against vandalism. Of course, keypads aren’t a particularly engaging user interface – you might get a green LED flash, or a beep.
A touch screen can do much more – you can drive an entire automation solution, get situational awareness, view video from the front door – there’s simply no comparison when it comes to functionality.
Capacitive touch screens are glass with a metallic conductive coating – basically the screen is covered by a low voltage layer. When you touch the screen, current is drawn to the contact point and there’s a voltage drop at an axis point in the screen’s electrode pattern that can be interpreted by controller firmware. The basic technology is robust. A quality screen can handle water, dirt, grease for hundreds of millions of mechanical touches.
Current draw is greater, but that price is worth paying, and typical operating temperatures are up to 70C, which is plenty. Speaking with suppliers in the industry, some say a lower quality unit might last 5-7 years. Better screens will last longer – perhaps 10 years, if installed indoors.
Whether or not you choose touchscreens or keypads – with or without LCD displays – comes down to the core demands of the application. Keypads will last longer but they are much less capable. Modern touch screens are so affordable, their shorter lifespan is a moot point.