There are a lot of intercom solutions on the market, from upmarket glitz to basic polycarbonate. You need to have a clear idea of what you need from an intercom before you make a selection.

Intercoms are a growth market in electronic security – some are tough as nails, while others are s0 beautiful it seems a shame to mess them up with fingerprints. But there’s a catch. Intercoms must combine looks with ease of use and flexibility of operation. And in industrial and commercial applications, intercoms need to be seriously rugged – the fewer moving parts the better.

There are 2 key physical elements of the intercom – the call panel at the front door or in the foyer of the building, and the handset within the residence or apartment. Of these 2 components, the call panel in the foyer is the most important operationally and you should devote a significant amount of time establishing its credentials before you make a choice. This call panel will be used and abused. It’s also the component that, if it fails, will throw what is essentially a resident-controlled access management system into total disarray.

Depending on the application, abuse won’t just come from users. In extreme environments there’s going to be rain, dust, electrical disturbance, vandalism and the entropic process of wear to contend with – all of which will challenge your intercom’s call panel.

In order to be sure of performance you can’t just read through a set of glossy specs in a brochure and accept them at face value. You need to take a long, hard look at the system – preferably with the building manager or developer of the property present to raise their concerns or issues. Also of benefit is to visit a site with the system you’re keen on actually installed and to check how it’s performing.

And talk to users and installers of the system and get their impressions. Nothing tests a product like operation in the real world – if the system is as reliable as the manufacturer says it is, there should be no problem with you getting a list of customers to call. All this might sound a bit extreme but if you’re pitching for a job in which 4 call panels and 50 or 100 handsets are to be installed, along with their associated cabling and subsequent maintenance, then you want to be sure of what you’re getting into.

When you think about the vandal resistance of call panels you’re balancing resilience and cost. You could buy something that would resist a sledgehammer but if it costs 5 times as much as the polycarbonate alternative you’ll miss out on the contract. It goes without saying that this cost element will colour your choice but we’re going to assume the property developer/building manager is sensible enough to accept your suggestion the call panel be able to handle real-world vandalism and still function.

This means you need a device built of high impact polycarbonate or of stainless steel. If the unit can handle a blow from a hammer, that’s good. Although beautiful shiny finishes that would be at home in a posh kitchen are the current flavour, you should bear in mind the shinier call panels are more likely to get attention from vandals. Matt finishes are easier to clean when they’ve been spray painted and they don’t look so bad after they’ve been set alight.

It’s also best not to pick a huge external call panel that looks like the cockpit of a jumbo jet. Look at the call panel as something that will assuredly suffer assault. Pick a solution that is simple and functional. If possible, go for something that flush mounts – it will be harder to pull of the wall. You want no screw heads in sight and all fixings coming in from the rear (this will come with its own set of challenges), and be sure all the metals involved in constructed are matched in nobility on the periodic table. If some silly soul has chosen a more or a less noble metal for screws or bolts in the interests of saving a few cents when it rains, the attachments will turn to powder.

When you look at a call panel, imagine you are oil, glue, soft drink, water, sticks or a wire coathanger. How can you get into that call panel when installed in a high rise residential tower and if you get in, what sort of damage can you do? Pay special attention to microphone and speaker apertures. These are where the vulnerabilities lie. And be attracted to potted electronics and coated boards – these qualities will save you money in the long term.

If there’s a camera present, you want the lens or the glass over the lens to be scratch resistant. The camera needs to be big enough to do the job without being so large it becomes a weak point. In terms of camera performance, seek the functionality to allow identification without going over the top. Obviously 720p is good but even now, D1 is fine. Call stations generally have the optimum angle and depth of field for facial ID at close range in good light using a fixed lens. Lighting might be an issue, so prefer something with low light capability or IR support.

Other operational features to look for include a door-propped open alarm and a tamper alarm – neither of which will be of any use unless they are monitored.
Have a look at all the buttons on the panel. Underneath these buttons you want a fluid and dust resistance membrane. That membrane should also isolate the buttons from the call panel’s electrical circuit. The last thing you want is someone shorting the system through the metal buttons on the call panel.

Your task will be made easier if the manufacturer has gone to the trouble of getting a NEMA 4X or IP54 or IP66 rating. There might be a lower IP rating – IP44 for instance – don’t use this sort of panel in a totally exposed external location or its life might be shorter than the 7-year guarantee the builder gives the development. Under a roofline, however, IP-44 should be fine.

Something else to think about with the latest video intercoms is integrated face recognition. This can work very well indeed and in the midst of the COVID-19 pandemic it can offer no touch or low touch access control that will increase the safety of residents, as well as offering a worthy sales hook, depending on your point of view.

Resident Handsets

Handsets or panels installed inside resident apartments don’t have the same need for bulletproof operation but they should still be of robust construction and designed to handle the rigours of regular use. They’ll need to be of tough polycarbonate able to handle bumps.

One of the key attractions of a modern system is how big the CCTV monitor is and how clear the image of the visitor will be. While all this is nice, there are other more important elements to an intercom solution. Features that are more important that oversize screens include easy operation and a connection that allows easy re-positioning should this be required. Another good feature is an off-switch that allows residents to sleep in or ignore visitors if they want to.

You also want 2-way communication initiated by the resident, not the other way around. You need 2-way so the resident can question the visitor should this be necessary. In addition, you want the front door release button to de-energize the strike on the front door for a limited time – not to jam it open for a whole day. While call panels should always have microphones rather than handsets, resident handsets are fine, taking into account the fact they will not be as reliable in terms of MTBF as a microphone-based call station.

Other things to think about with modern intercom systems include whether you go for colour or monochrome cameras. This issue will be one of cost and attractiveness to the user – both solutions are workable. There’s no question that a CCTV-based intercom does allow a greater level of identification and therefore, security, than a voice-only solution. Once again, it’s down to the dollars.

The latest systems feature snazzy options like VoIP, remote management and maintenance software, addressable devices and Ethernet compatibility. Your selection in relation to these will be guided by the infrastructure of the site. Nice things to have would be PoE, or in simpler systems, the ability to piggyback on the existing phone lines. Much depends on the infrastructure of the site you’re working on.

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