Concealed Vertical Cable SystemBy: Brian Rhodes, Published on Jun 19, 2012
Nothing seems more tedious that adjusting door hardware, and adjusting concealed vertical rods is the biggest pain of them all. Every door access control provider is forced to work with these devices at some point and getting things put back together properly can take hours or days. One of the biggest names in door hardware has announced a product claiming to eliminate all the headache with concealed vertical rods. We analyize Von Duprin's Concealed Vertical Cable System in the note below.
Vertical rods are most commonly used in two applications:
- Multi-Point Security: Because securing a door from two points is more secure than just one, vertically mounted latches serve to make a door 'more secure' and harder to tamper with from the unsecured side. Vertical rods permit a door to be secured from the upper frame and threshold, rather than only the 'strike' side of the frame.
- Double Doors with no Mullion: In order to secure 'mullion-less' double doors, some method of vertical latching must be used. Instead of using 'exposed' or surface-mount vertical rods, many architects specify 'concealed' hardware that is discrete and does not detract from interior design.
Unfortunately, burying vertical rods inside a door prevents them from being easily accessed and maintained by technicians. In addition to being difficult to 'reach' for adjustment, because the hardware is obscured, it is difficult to determine how much adjustment is enough. The ominous phrase "blind adjustment" is commonly used to describe this process.
The manufacturer's product launch video covers the basic design and features of the system and their proposed:
The Concealed Vertical Cabling system features the following
- Product routes twisted steel cables inside hollow core steel doors to actuate top & bottom latches via exit device
- Central clevis bar assembly mechanically matches up with select Von Duprin exit devices
- Installs and adjusts without removing the door from frame
- Manufacturer claims "2 minute" installation time
- Flexible cable can accomodate slight door or frame warp, where rods cannot
- UL Fire Rated version available
- Uses standard 'concealed vertical rod' door prep (retrofits to existing doors)
- All standard finishes available
- Price: $800 - $1000 depending on door height and Fire Rating
Labor Saving: Some concealed vertical rod designs require the entire door be taken down for service. The heft of the door often requires two men to safely remove, and this might need to be done two or more times before proper adjustments have been made. Even experienced technicians/locksmiths can take a full day to install and service concealed vertical rods. Von Duprin claims their CVC system takes one man minutes to install, seconds to adjust, and can be done without removing the door. This claim could translate into eliminating hundreds of dollars on a typical maintenance call on these devices.
Limitations on Exit Devices: Because CVC is a Von Duprin product, it only works with Von Duprin 98/99 and 33/35A series exit devices. The cable system supports 'mechanical latch retraction' and 'delayed egress' functionality, commonly used with electronic access control systems.
Long Term Cost Savings: While the hardware cost of this system is slighlty more expensive than concealed vertical rod kits, it requires less labor to keep adjusted over time. Assuming that a full day of technician labor can be condensed to a few minutes, it is reasonable to estimate that over $400 in labor can be saved every time these latches need to be adjusted. For this reason, we see value in the idea, and expect competing products will follow suit.