The first thing you want to determine when you’re looking for office wireless intercom systems is what application will it be used for. Many times when we talk to people looking for a wireless intercom system they want the same functionality they will get from a telephone system. Meaning they want to be able to call specific offices or desks like they could with a telephone system. Unfortunately a wireless intercom really doesn’t fit this application well.
A phone system has the advantage of being able to assign extensions that people can dial and the phone system routes the call. Wireless intercoms don’t have that capability. They do have some wireless channels that you could in theory use to call individual offices, but if someone changes off of their assigned channel to “call” you on your channel, and after the call they don’t change back, no one will be able to contact them. Wireless intercoms work best for broadcasting to everyone.
The other thing you need to decide is what frequencies the intercom needs. There are intercoms in the 900MHZ, VHF and UHF frequencies. This essentially comes down to the coverage you need. 900MHz will only provide a few hundred feet of range. VHF intercoms have more power and lots more range, but they do not handle the interference cause by a building’s construction as well as UHF intercoms do. However, all of these types of intercoms have applications they fit well in an office so there is no easy answer on the best one.
You can find more information on wireless intercoms systems at http://www.intercomsonline.com