An Intercom System – what is it?
Intercom stands for intercommunication. The intercommunication is next to always by voice. A video intercom system additionally sends a video-feed to the receiving intercom telephone handset.
An intercom system mostly consists of an intercom panel at the main door or gate. That panel can have just one call button or many.
Each button on the outside will address one or a group of telephone handsets inside various offices or flats, which share this particular access door or gate.
The intercom telephone handset allows voice contact with the visitor at the main door or gate. Additionally, the main door or gate can be opened remotely via a button on the telephone handset.
Many varieties of intercom systems have developed over the years:
+ A video intercom system additionally has a camera built into the panel on the outside, which then transmits a colour or mono image of the door or gate area to a telephone handset with an in-built little monitor.
Upmarket apartment or office blocks often use video intercoms. The disadvantages are the overall cost and the fact, that the outside panel – the most valuable bit of the system – can fall prey to vandalism.
+ As a special application, often used in the care and old-age sector, the video intercom system can be linked to a television.
+ A digital intercom system replaces a large multi-button panel with a simple keypad combined with an inbuilt speaker/microphone unit. The keypad allows you to press in the number of the office or flat you want to reach. This is an unobtrusive, elegant and long-lasting solution for large blocks of flats or offices.
+ Again for larger premises, one can consider a telephone based intercom system. The outside panel would be in the form of a keypad, combined with a plain vanilla telephone line. Alternative, the panel could run with a GSM module (see picture). Pressing in the number of the desired flat or office would result in a telephone call being made to that flat or office. The call-recipient can then press pre-defined number sequence on the receiving telephone to open the door.
The great advantage of this solution is the near complete absence of any wiring, which, traditionally, would have to run to each office or flat. The drawback is the frequent worry about telephone call charges.
+ A wireless intercom system looks similar to a traditional one, but the connection from the panel to the handset goes without any wiring. Usually, standard DECT technology is used.
Wireless intercoms are useful for listed buildings with severe building restrictions. Also, there are many users in the care and old age sector. Users might not be able to easily reach the intercom handset, if it was mounted on a wall. A wireless intercom handset can be near the bedside and otherwise be carried round during the day.
+ Many intercom systems have a tradesmen’s button, which allows the door to be opened for post and milk-deliveries. The postman would simply press the tradesmen’s button, and the door would open. This requires a time clock, to define the length of the tradesmen’s access period. A tradesmen’s button adds an inherent element of insecurity to an intercom installation. If it can be avoided, then it should be avoided.
+ Often an intercom system is combined with a keypad or a fob-reader, to allow easy access for tenants or staff
The upshot of it all is this:
If you’ve ever had an intercom system in a flat, you’ll never again want to be without one.