Conclusion: Automatic dryers are better, but more expensive.
In the old days, there were no choices. If you wanted a hand dryer (or hand drier, depending on where you live), you got a push button, cast iron dryer, and it did the job. In the 1980’s, hand dryers began appearing in automatic versions, with infra-red sensors that detected the presence of hands under the dryer’s nozzle.
The advantages of automatic dryers are obvious. The first is hygienic. You don’t have to touch an automatic hand dr
yer, reducing the possible spread of germs that could be left on the dryer. The second is energy savings. You only use the dryer for as long as you need it. Many timers are set for 30 seconds. But the user may choose to leave after only 10 seconds of drying, wasting the energy used for the rest of the cycle. On the other hand, another user may dry his hands for 35 seconds, wasting almost an entire second push of the button.
With these obvious advantages, you would think that all new hand dryers would be automatic. Yet we still see a large portion of our sales are still push button. Why are people still purchasing push button hand driers?
For one thing, many of the specifications out there are left over from years ago, when hand driers came in only one flavor. Push button may have worked for you in the past and you don’t see any reason to change that now.
Secondly, there is a perception that mechanical push button dryers are more durable and easier to fix than
electronic sensors. When sensors first were introduced they were less reliable than the tried and push-button timers. The eyes could be either too sensitive, going off simply by the reflection of light against the surface below (a problem known as “ghosting”), or not sensitive enough, not activating the dryer at all. (You may have a particularly bright environment that is not friendly to an electronic sensor.)
The first generation of sensors also had short life spans and needed to be replaced too frequently.
However, as electronic technology has improved, these problems are no longer so prevalent and sensors and their circuit boards can now be some of the most reliable components in the dryer.
It is possible to encounter some problems with sensors, but mechanical push button timers can also have problems with the timer or the push button itself. In either case, a simple fix is usually available by replacing a couple parts.
In my experience, sensors, which have fewer moving parts, are more reliable than push buttons. The sensor usually costs more, however, so you may pay more for your automatic dryer than you will for your push button dryer, (but you should be able to make up the difference in energy savings).
The third and probably the main reason why a lot of push button hand dryers are still
specified is that some people feel that they are not as easy to
vandalize as motion-sensor hand dryers. This is because some vandals
will try to damage the automatic sensor either by scratching it or
putting gum on it. I have not seen this problem occur a lot, but my school system friends tell me that anything that could possibly happen in a restroom ... will.
The sensor eye is of course made to resist
scratching, and even a scratched or partially covered sensor will still
work, but is is possible to do some damage if one were to really work
at it. Additionally dryers are programed to stop running after a period
of time if the sensor is blocked, but the substance still needs to be
removed from the dryer by a maintenance person.
On the other
hand a push button can also be vandalized, but maybe not as easily. It sometimes happens, for example, that you will see the button itself sprung out from the
cover. This occurs when the clip holding it in place pops out. It can
be fixed by purchasing a new clip.
In the end, I feel that the convenience and hygiene of an automatic dryer is well worth it, and I would always recommend purchasing automatic over push button. No one these days wants to touch anything in the restroom and I particularly dislike banging those buttons.
As new dryers are designed, you will notice that they are only being designed with automatic versions. Eventually, there will be no more push button hand dryers. For the time being though, they are still popular and you may find for whatever reason, that they are right for your application.
For more information on hand dryers, email firstname.lastname@example.org.