by Lee Russell

Created on: February 01, 2010

Home security systems can be divided into two main categories: hardwired and wireless. Both types offer similar features for arming, disarming, fire protection, monitoring, etc. The main difference between the two lies in the kinds of houses where they are used.

Hardwired systems have all detection devices and keypads connected to a control panel with low-voltage wiring. Hardwired systems can either be pre-wired during construction or retrofitted to an existing home.

In a wireless system, the sensing devices are radio transmitters that communicate with a control panel and receiver. These systems can be used in almost any type of dwelling, since little or no wiring needs to be installed.

A hardwired system is the most reliable choice, assuming the construction of the house allows wiring to be installed. The sensors are directly connected to the control panel and can communicate instantly for immediate response. At the same time, the wiring and devices can be constantly supervised; if a problem is detected, it will cause a trouble signal at the keypads (and at the central station, for monitored systems).

Wireless systems, on the other hand, send alarm signals over the air. Radio frequency (RF) interference can disrupt communications between the remote sensors and the receiver, possibly preventing an alarm from being detected.  Since there is no wiring, supervision is accomplished by sending periodic check-in signals to the main panel. If any transmitter misses its check-in, a trouble signal is generated.

Check-in signals are typically programmed to transmit every few minutes. This means there is a trade-off between sending signals often enough to supervise the devices properly, but not so often that battery life is shortened.

Cost is another factor in favor of hardwired equipment. Door and window contacts may run $20 to $30 each installed, for a hardwired system. Wireless transmitters are about $60 to $70 each installed, and must have their batteries replaced every three to five years. Some houses may have 15, 20, or more doors and windows, making a wireless system very expensive to install. Keypads, motion detectors, and other devices also tend to cost more in their wireless versions.

The area where a wireless system would be the clear choice is in a home that hasn't been pre-wired, and has no attic or basement spaces for running wires. In this case, the drywall and other damage involved in getting wiring installed would outweigh any cost savings. Wireless equipment would be the only option for securing the home.

If a house has limited wiring access, a hybrid system would be a good choice. These are wireless panels that also provide several hardwired zone inputs. Standard wiring and switches are installed wherever possible, while inaccessible parts of the house are protected using wireless transmitters. This is cheaper than going all wireless, and would eliminate future battery changes in the hardwired areas.

Whichever type of system is used, central station monitoring is recommended to provide police or fire department response. Both types of security system should be tested often and kept in good working order. Many alarm installing companies offer maintenance contracts to take care of service.

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