A personal doorphone is an integral attribute of any modern house or apartment. It refers to one of the most affordable security systems (both in price and in ease of use) along with video surveillance. However, it is not so easy to choose and install a doorphone.
Therefore, it is necessary to determine the minimum list of devices and accessories required for the full operation of a doorphone system.
The standard set of doorphone system includes the next compulsory components:
– A calling panel – is one of the main components placed in front of the door from the visitors’ side and is a modified and more functional analog of doorbell button.
– A video doorphone – is, in fact, the most important component of the system, which provides the monitoring of the visitors and a direct access control – the opening of the lock.
– A set of cables – is used to power and connect the call panel to the central video doorphone. It is also necessary to have a power supply and a lock control unit if you use an electric lock.
In addition, one more optional component:
– An electric lock – is an optional element of the system for those who want to operate the lock remotely. It is mainly used in cottages or private houses: where the entrance distance to the territory is sufficiently removed. The modern apartment buildings usually have electric locks.
The other accessories, such as a mounting kit or a doorphone/callin panel bracket are included in the standard set of these devices and you do not have to buy them (if you do not use any nonstandard installation system).
Now we will describe each of these components, and we will start from the calling panels.
A calling panel
As it was mentioned before, the modern calling panel is a modified version of the well-known call button but with the enhanced functionality.
The modern calling panels are equipped with not only a button, but they also contain such components as a video camera (often with infrared illumination), a microphone and a speaker for two-way audio communication with the visitor. It also may include the relay for remote opening of the entrance door.
The most important technical characteristic of the calling panel is, probably, the resolution of the built-in video camera and the presence of infrared illumination. The higher is the resolution of the video camera, the better image you will get on the screen of your video doorphone, but do not expect the great quality: it is often at the level of 0.3 MP. However, it is enough to fix the face of the visitor: for example, the Myers D-200 calling panel have a camera with a resolution of 600 TV lines, – such resolution has recently been the maximum for professional video surveillance camera, and now the calling panels of doorphones are equipped with it. Therefore, this camera will cope with the task of fixing faces of your visitors without problems. The infrared illumination is also necessary for shooting people in the low light conditions. Its range usually is 3-5 meters.
When choosing a panel, make sure that its housing is reliably protected from dust, moisture, and extreme high/low temperature. As this device is located on the outside of the house in 90% of cases, and so strong housing is necessary for its reliable work. For example, the Myers D-100C calling panel has such protection and the operating temperature range is from -40 to +65 degrees, which is more than enough for our climatic conditions.
The calling panels have similar characteristics, but the main difference lies in the materials of the housing and its design. You may choose any that will be in harmony with the design of the front door or the exterior around it.
A video doorphone
The main component of any doorphone system is, peculiarly, the indoor unit that includes the electronics, the screen, and the access control elements.
It is necessary to single out three points that may arise when choosing a doorphone:
The first point is a standard of the video signal: IP (network) or analog. There are a few models with IP standard but they are more expensive, and if you do not need to see the faces of your visitors in HD-standard, then it is not necessary to have IP system. The choice of such standard will significantly influence on your budget, as the same network calling panels are suitable for this type of monitors and the mounting of such system is more complicated.
The second point is the screen: TFT/LCD or CRT. The doorphone with CRT-screen is not always on sale as it is outdated. In addition, they significantly enlarge the size (thickness) of the doorphone. A new generation of screens, namely, TFT/LCD do not have this drawback and their price does not much exceed the outdated analogs.
The third point is a doorphone with a receiver or without it. The Hands-Free (without receiver) doorphone in 95% of cases is handier and more attractive in the interior, that is why we recommend you to decide in favor of it.
Speaking of the screen, there are several widespread sizes: 4 and 7 inches. The 7-inch models are relatively inexpensive and are used in cases when there is one calling panel or there is not a significant flow of visitors. In addition, they have relatively compact size and do not take up a lot of space on the wall. They are rarely sensory, usually, they have mechanical buttons and this feature does not detract from their advantages.
The 7-inch screen video doorphones are more expensive but they are much more convenient in everyday usage. They are indispensable in cases when several calling panels are connected. These models are equipped with a touch screen or touch panel control, and you can easily view the video from multiple sources at once, such as several additional calling panels – for example, one can be installed at the front door, and the second – at the back door. Such systems are also often installed in the offices. As it was mentioned before, many models have the possibility to connect additionally one or several video surveillance cameras. Therefore, you can see the visitor or the entrance from several angles. You will not have a complete video surveillance system but you will be able to carry out an additional monitoring of the territory.
Another useful feature of almost every doorphone is intercom – the possibility to make calls from doorphones connected by a common network.
To store the photos of visitors coming in your absence, the video doorphone is equipped with a memory unit designed for a certain number of frames. Models that are more expensive are also equipped with a slot for memory cards holding a significant amount of recorded photos and even video data. This technology helps you to be aware of who and when visited you.
When it comes to the «appearance» of video doorphones, the variety of models allows you to choose a design for almost any room: the models with neutral design are suitable for offices, for example, M-72SD White or M-43 White. The models M-42SD Black or M-73SD Gold are suitable for home, and for interiors in the high-tech style – M-75SD Touch or M-41SD Silver. The budget frameworks are quite broad: from 70 $ for a 4-inch screen model with good functionality.
If you are not on friendly terms with the mounting of low-current systems, it is better to entrust the mounting of video doorphone to a professional. The process of connection of such system is quite specific, it is necessary to stain the walls in most cases and this process cannot be done without a specialized instrument. An additional point is that the cabling should be done carefully: a large accumulation of electrical conductors, usually concentrated at the entrance doors and in the internal walls, can generate significant interference causing the background noise and distortion of the video signal.
If you want to install the system yourself, then see about a necessary instrument and familiarize yourself in details with the installation instructions and mounting recommendations on laying of communication links.
The most common connection scheme for a doorphone is a four-wire scheme with each of the four connected cable cores being responsible for its tasks: a video signal, audio signal, power and «ground». It is better to connect with a help of four-wire cables for transmission systems or cords in vinyl insulation (PVC).
There are also wireless systems that use a radio channel to connect the calling panel and doorphone, you should remember that such systems are very sensitive to interference so they must be used very carefully. Do not forget that if you have an electric lock in your access system, it also needs power with an additional conductor, power supply, and lock control unit.
So, let us summarize the main points of choosing and buying a doorphone:
These are the main points to take into consideration when selecting and installing a video doorphone. The rest – design, and functionality depend only on your budget and the set of tasks for this device to solve.
If you have doubt about the correctness of your choice and you need a specialist’s consultation, contact our store and the managers will help you to choose the model according to your budget and required tasks.