Prewiring ERCES: Anticipating a Need Before It Becomes a Problem
Mechanical, Electrical, Plumbing, Fire Alarm and Fire Suppression are all at the top of most General Contractors' lists. Most are not aware that while they are using materials that are cost effective or energy efficient, they are also actively creating resistance to radio signals for first responders. So, what do they do when the building is complete, and the Building Inspector or Fire Marshal cannot connect their radios to the radio tower outside? Well, unfortunately they will not receive their Certificate of Occupancy. As a BEST case scenario, they will get a Temporary Certificate of Occupancy until they provide adequate radio signal throughout the building and, more importantly, what are referred to as "critical areas."
When a GC is faced with this problem, they will often rely on the expertise of the fire contractors for advice on how to solve the problem. Those contractors will suggest, in layman's terms, a sort of First Responder WiFi system called an ERCES. This system collects the outside radio frequencies used by first responders and distributes it through coaxial cable to interior, often ceiling mounted, antennas. The issue most often faced in a scenario like this is that the ceilings and walls are already constructed, making running commonly used 1/2" coaxial cable extremely difficult. Not only is it difficult from a "retrofit" perspective but also an architectural one. Many architects have aesthetic limitations that may prevent contractors from simply adding conduit or metal raceways to support coaxial cable installation. This highlights the importance of anticipating the need for an ERCES in commercial infrastructure.
Adopting the practice of prewiring buildings for ERCES's is a way to preemptively prevent costly, and in some cases nearly impossible, cable installation that would require ceiling and wall demolition. Many contractors install coaxial cable labeled "for future use" as well as access panels in hallways so they do not need to reopen these finished spaces. While this may increase costs at the front end, it is a significantly more efficient and cost-effective practice compared to installing cable after the building's construction has been completed.
Simply knowing what the building's construction is expected to be, you can anticipate whether an ERCES will likely be required or not. Materials used, building location and line of sight to the radio towers used by first responders can affect radio frequency range and interior penetration. Dense materials such as concrete, energy efficient materials like low emissivity glass and the number of expected interior walls increase the likely need for radio signal enhancement. Buildings that are in densely populated areas must contend with not only their exterior construction but also the surrounding structures that may be blocking signal coming from the radio towers. The opposite could also be a factor. If the building is in a more rural area, the ambient signal outside the building may not be strong enough to penetrate the exterior of the building, resulting in low interior signal strength.
Considering all these factors will help you anticipate if your project could potentially require an ERCES, and consequently the installation of cable, splitters and antennas. Proactively installing harder to manage components like 1/2" coaxial cable risers and horizontal branches will help keep installation costs down should you end up needing a system after the interior of the building has been completed. Just remember to label the installed cable as "for future use" to stay NEC compliant.
