As described in the wiring the home document, there are several media available in the home LANs, and the feasibility for the applications described below depends on the wiring infrastructure and the degree of sophistication used in the installation. A complete home automation system (HAS) could cost anywhere from several hundred dollars to tens of thousands for a luxury home with controls for every electric component in it. Here is a description of some of the applications in home automation.

ENERGY MANAGEMENT

Using intelligent power meters, the utility companies could implement an automatic reading meter program leading to an electronic billing plan. Besides, peak demand and power management inside the house can be implemented based on the information provided by the meter to the network. Real time outage recording as well as immediate location of spot problems can be relied back to the utility company. All of the above applications can be implemented using telephone, radio frequency, power line carrier, cable TV or an hybrid of the above media; being the telephone network the most reliable and cost effective for communication between the house and the utility monitoring station.

The utility company will inform the home about peak power demand times and the home system will reschedule all the non-critical power demanding chores to a low power demand time implementing this way a Demand Side Management (DSM) program. This approach benefits the utility company as it will not be required to embark in costly expansions and the residential customer will reduce the utility bills.
 
 

ALARM SYSTEM

Conventional alarm systems can be interconnected with the lighting system of the house to create the sense of occupancy of the house when the owner is away. In case of an emergency such as a fire or flood, the system will turn on the appropriate lights in the house that indicate an escape route, while at the same time the audio system will warn and direct the occupants. Also, whenever any break-in is detected, all lights in the house will turn on as the alarm system informs the neighbor and/or the police about the emergency via telephone, cell-phone or a radio frequency link. A log of the most recent events will be kept in the system's memory and could be retrieved locally or remotely via modem.
 
 

LIGHTING SYSTEM

House lighting control can be made via power line carrier (PLC) or dedicated wiring schemes. The PLC method allows the possibility of implementation in existing homes without home automation pre-wiring (retrofit market). There are specialized lighting control systems that require specific wiring networks and this method is done mainly in new construction for obvious reasons. This systems are usually proprietary and more expensive. All these systems can be controlled by the central master unit.

Using automated lighting control, different scenes can be implemented and "played" using just a push button in the wall, the telephone or even voice command if the master unit includes this facility. As explained above, the lighting control system can be interfaced with the alarm system as well as the Audio/Video system of the house to create theater or party scenes as programmed by the owner. Also, combining this system with occupancy sensors, allows the homeowner to turn-off the lights in unoccupied rooms after a pre-determined period, and vice-versa.
 
 

HVAC SYSTEM

The Heat/Ventilating and Air Conditioning system could benefit greatly with a HAS. If the HVAC control unit is interfaced with the home LAN, the zoning of the house could be easily implemented therefore reducing the energy consumption and increasing the comfort. In a zoned house, each area has its own thermostat and the air ducts leading to it have a motorized damper. When a zone thermostat calls, two events occur: the central HVAC unit starts and all the dampers serving the non-calling zone close, preventing the use of conditioned air in zones that do not require it.

When this system is interfaced with the master control, it can be pre-programmed to set back the temperature in the whole house several degrees whenever the alarm system indicated the away mode. The savings in energy are dramatic and the homeowner do not have to remember whether the thermostats were set or not. This can be looked at as another application of energy management.
 
 

AUDIO/VIDEO SYSTEM (HOME THEATER)

This is an application that have blossomed during the 90's. Every homeowner wants to have some degree of home theater installed. It ranges from the TV, VCR and Audio Amplifier connected together all the way to sophisticated systems that interconnect satellite-delivered digital TV with Laser Video disks and Hi-Fi Surround systems. When properly designed as part of the HAS, it can be controlled from anywhere inside or outside the home. It can be interconnected with the surveillance, alarm and lighting systems to provide more comfort in the house.
 
 

MISCELLANEOUS SYSTEMS

Windows and Blinds

With the appropriate sensors, the window treatments such as blinds, curtains and shutters can be controlled automatically to close if the sun is set in that part of the house. They can be programmed to open and close at random times to give the sense of occupancy. If combined with the video system, the blinds can be closed when the "movie" command is issued. If used with rain and temperature sensors the windows will automatically open and close as necessary.

Water Management

The indoor plant watering and exterior irrigating (sprinkler) systems benefit greatly from a home automated system. They can be programmed to do the irrigation at pre-determined hours only if it has not rained and there is not a party scene in progress. They can also be combined with flow control devices, moisture, wind and humidity sensors that allow the system to adjust the watering schedules accordingly.

Pools and Spas

The pool functions such as lights, pumps, valves, filtering and cleaning systems can be automatically controlled with the HAS. Monitoring devices are available to protect heaters and pumps. All this control and monitoring can be done locally or remotely via telephone or modem links.
 

SUMMARY

In summary, the technology available today allows the home owner to have a complete Home Automated System in which all the electric and electronic devices present in the house are interconnected using the proposed home LAN, yielding a safer and more enjoyable environment. The engineer-installer has to work closer with the home-owner to ensure that the programming of the system accommodates the owner's life style, and that all the sub-systems work according with the proposed design parameters.