Wiring The High-Tech House - Continued

How Much Is Enough?

I recommend installing two coaxial cables (RG-6 shielded wire) and two Cat-5e twisted-pair cables in every major room. The wires should all run to a location where they can be connected to a single gang wall plate with receptacles for phone, computer, and video (Figure 5). The client doesn't have to use all of them right away, but they will be there if needed.

Figure 5.Low-voltage wiring does not require conventional electrical boxes. This green bundled cable goes to a mud ring (left), but it could also go to an open-back box. The cable, which contains two Cat-5e and two coax cables, will terminate at a wall plate (above) with connection points for multiple devices.

A bare-bones system might include a distribution panel plus boxes (with two Cat-5e and two coaxial cables) in the master bedroom, kitchen, and living room. The homeowner would probably use it for the phone, to share an Internet connection, for network computers, and to run television off shared video sources such as a DVD player, cable, or satellite. In new construction, the installed cost would be about $375 ($75 per room plus $150 for the panel).

An average system would include all of the above, plus runs to other bedrooms and to extra rooms like the office, den, loft, and basement. In addition to phone, TV, and computer, the owner of a system like this would probably have monitoring cameras and perhaps a whole-house audio entertainment system. The wire runs still cost $75 each, but this system would require a larger, $350 panel. Assuming an additional six rooms (four bedrooms plus a den and office), the structured wiring would cost about $1,000.

A better system, containing all of the above, plus runs to more locations and fiber-optic cable for future needs, could cost $4,000 or more.

All of these prices are for new construction; unless the building has been gutted, it costs much more (two to four times more) to retrofit an existing home. The above estimates don't include the cost of modules and electronic equipment.

Future Needs

Because it's so much easier to install wiring when the walls are open, it's a good idea to install extra cable or a chase to areas where wire might be needed at some future date.

I recommend running 2-inch PVC pipe between the distribution panel and the attic, so you can get wire to rooms on the second floor. Because new entertainment equipment is being introduced all the time, I often run empty conduit from the distribution panel to the area where entertainment equipment (audio or home theater) might someday be located.

It's also a good idea to run speaker wiring from the distribution panel to areas where the owner might want to listen to music in the future. The volume and audio source is typically controlled by wall-mounted keypads in the individual rooms, so run Cat-5e wire to the keypad location.

Another option is to run extra wire to the thermostats so the owner can activate the hvac system remotely or avoid the hassle of using a programmable thermostat. Depending on what equipment is located outdoors, you might want to run wire or conduit there, too. With the right equipment, lawn sprinklers, pool pump, and spa heater could all be remotely operated. Other options include a door phone, outdoor speakers, and an outdoor camera for keeping an eye on the kids.

What about wireless? Wireless connections are an option for certain kinds of signals. They are a good way to share an Internet connection with a laptop that is used in multiple locations. However, a wireless connection is unlikely to be as fast or as reliable as one that is hard-wired. Also, there may be security concerns, because wireless signals do not stop at the wall of the house. Without a proper firewall, neighbors or passersby may be able to pick up the signal and access the homeowners' Internet connection or hard drive. I think of wireless as a supplement to — rather than a replacement for — a hard-wired system.

Installing the Components

Prewiring is the act of pulling all the low-voltage wires and installing the service panel and boxes. Household wiring can cause electrical interference, so it's important to keep low-voltage wiring away from it. Ideally, structured wiring should be at least 12 inches away from electrical wires; 24 inches is even better. At some point, a low-voltage wire may need to cross household wiring. When that happens, be sure to cross at a 90-degree angle to minimize the amount of electromagnetic interference.

Figure 6.Because household electrical wiring produces interference, the installers keep the blue low-voltage cables away by running them along a different ceiling joist than the Romex (left). If structured wiring has to cross high-voltage wiring, the two types of wire should cross at a 90-degree angle to minimize interference (right). In this case, the low-voltage cables above the joists are perpendicular to the household electrical wire that runs along the sides.

Because many mechanical subs and electricians are not aware of these requirements, it's important to let them do all of their rough-in work before installing structured wiring (Figure 6). I don't want an electrician coming in later and running his wires close to (or through the same holes as) my low-voltage wiring to save time. And low-voltage is more delicate than household wiring, so it's important not to staple, fold, crimp, or splice it. (Where fastening is necessary, I loosely wrap the cable — or bundle of cables — with a cable tie and then either staple or screw the loose end of the tie to the framing.)

When I'm running wire for future in-wall speakers, I like to leave some extra in the wall so that it's easier to shift the speakers' location. It's also smart to document the location of prewire items by photographing them before the drywall goes up (Figure 7).

Figure 7.The best way to prewire for future speakers is to leave extra wire and loosely staple it in a zig-zag pattern across the bay. This makes it much easier to find the wire later on.

Locating the panel. It's easier to wire the house if the distribution panel is centrally located. It can go in a closet or in the mechanical room; the important thing is to keep it at least 24 inches away from the electrical panel — 36 inches (or more) would be even better. Some of the devices in the panel may require power, so it should have a dedicated 15-amp line that enters the panel from a different end than the low-voltage wires.

I try to install the panel in a conditioned space so it will be easier to work on. Protecting the panel from temperature extremes also makes it less likely the modules will go haywire because it's too hot or cold.

Final connections. Once the drywall is up and the walls are painted, it's time to terminate the cables and install wall outlets. This part of the job includes making connections within the distribution panel and using electronic test equipment to verify that the in-wall cables are correctly connected.

Unlike electrical wires, which are stripped and screwed to terminals, low-voltage cables are terminated by clipping them into the backs of wall plates or by attaching them to pluglike coax or RJ-45 connectors (Figure 8). I use a hand-held crimping tool to press the connectors onto the cable. Once the connector is on, the cable can be attached to the wall plate or plugged into a receptacle in the distribution panel.

Figure 8.Four twisted pairs of Cat-5e cable clip into the back of a wall-mounted control device (left). Once installed, the device will control the speaker volume in the room and access an audio system that is installed elsewhere in the house (right).

With several cables terminating at every wall plate, keeping track of which cable goes where can be tricky. To avoid confusion, I like to color-code my cables (cable is often available in different colors). For example, I'll run video-in with black coax and video-out with white coax. The Cat-5e wire to the boxes can be color-coded in a similar manner: gray for phone and blue for data. Color-coding the receptacles on the front of the plate (phone system gray, data jack orange, and so on) has made a lot of my clients happy. At the very least, use consistency in how you connect wall plates throughout the house — so that, say, phone jacks are always in the upper left. If you can't do that, label each receptacle.

When the cables are pulled, they come into the panel and run long. There are a lot of them, and the only way to keep track is to label each one with a marker, number tape, or write-on label. The color and type of a wire may tell me what it is, but I still need to mark where it goes (Figure 9).

Figure 9.

With home-run wiring, there are a lot of cables, so after installation it's important to mark each one with the same information that's on the wiring chart.

Finally, I use an electronic tester to verify that the individual cables are intact and properly terminated at both ends. At this point, modules can be put in the panel, and phones, computers, and electronic devices installed in various rooms. If anything needs to be rerouted, it's just a matter of plugging or unplugging, either in a room or in the distribution panel.

Helen Heneveldhas 15-plus years of experience in the home automation business and is co-author of the manual and certification guide HTI+ Home Technology Integrator & CEDIA Installer I All-In-One Exam Guide.