Controlling Your Home By Computer
Sharon Darling, Research Assistant
In the cartoon home of George and Jane Jetson, computers controlled everything from preparing meals to walking the dog. While such a supercomputerized house seems somehow overkill, reality has begun to catch up to the Jetson fantasy. There are some serious applications for the home. Your computer can connect to a variety of devices which let you control alarm systems, monitor heat and air conditioning, start your dishwasher, and even activate your coffee pot in the morning.
If we were still in the energy crisis mind-set of a few years back, William Brayden might now have more business than he could handle.
His company, Savergy, Inc., sells two control devices he developed for the Commodore 64 which will monitor and control energy use. While he estimates a homeowner can save at least 25 percent on energy consumption by using control devices, he says sales of his Computer Interface Module 112 have not been as great as he initially expected.
"We've seen a considerable attitude change in the last year," says Brayden, who has been in the energy management field since 1978. "It's like when gas first went up from about 30 cents a gallon to a dollar—everybody screamed about it, but nobody's screaming about it today. It's the same thing with home heat and energy—they were screaming about it like crazy. Now a lot of people tend to accept it rather than do something about it."
Brayden remains convinced, however, that computer owners who don't take advantage of their computer's capabilities to help control their homes are missing excellent opportunities to save money.
Savergy's Commodore Systems
Brayden offers two methods of cutting costs, both of which use the Commodore 64 or VIC-20 as controllers. Savergy's CIM 112 ($479) is dedicated to controlling large appliances such as water heaters, washing machines, air conditioners, and the like. The Powerport ($99.95) turns lights on and off, controls lawn sprinkler systems, and even operates the percolator.
"You're never going to be able to do any serious energy management by controlling lights and coffee pots—you have to be able to control the high power loads that are really eating up the electricity," Brayden says. So, while devices hooked up to small appliances and controlled by your computer can be convenient, they're not going to save you much money.
Brayden's software uses time-of-day scheduling and duty cycling to conserve energy usage. With duty cycling, an appliance such as an air conditioner can be turned on for a preset number of minutes, then turned off. The cycle would then be repeated. With a traditional system, the air conditioner runs continuously, until the desired temperature is reached.
Brayden explains that with duty cycling, the temperature "kind of peaks out in a nice, round peak and then tends to start tapering off—it doesn't immediately drop down to its off temperature, so if you turn it on for four minutes, and turn it off for one minute, you have an 80 percent duty cycle."
Apple, IBM, Commodore Connections
During that one minute off-time, heat or air conditioning would still be radiating throughout the house, Brayden says, but for free, since the compressor would not be operating. "The combination of turning things off through scheduling when you don't need them on, and duty cycling them if they are appropriate for that, is how we very conservatively came up with the 25 percent savings," he adds.
A simple computer control system might begin with appliance controllers, since they are fairly inexpensive and relatively easy to install, says James Coffron, author of several books on computerized home control, including The IBM PC Connection, The Commodore 64 Connection, and The Apple Connection (Sybex).
Coffron estimates that a person could set up a simple system, using a Commodore 64, for around $200.
The heart of most control systems for small appliances and light switches is centered in modules (available from BSR Ltd. and Leviton Manufacturing Co., among others) which plug into the wall, and receive instructions from a computer. Your computer sends a signal which is received by the BSR module. The results, for example, may be that the lights are dimmed, the stereo starts playing music, the coffee pot turns on, or any of a hundred other computer-activated chores are carried out. (For more do-it-yourself information, see COMPUTE! Books' Home Energy Applications On Your Personal Computer.)
The Genesis Controllers
Another firm which makes a series of home control products that can be used separately or together is Genesis Computer Corporation. The products run on either the VIC-20 or Commodore 64.
ESI's Savlt is an automatic temperature control system which contains its own computer.
Genesis' VIController ($69.95) is a plug-in unit with software on disk which is used in conjunction with remote BSR-type switches to automate appliances and lights through time-of-day scheduling.
The firm's COMsense device (also $69.95) allows doors and windows to be hooked up to the computer. Used in combination with the VIController and magnetic reed switches, a simple home security system can be set up.
Let's say you want to have your computer flash the lights on and off if a door or window is opened. The magnetic reeds (available inexpensively from hardware or appliance stores) are attached to the doors and windows that are to be monitored. When the connection is broken, the reeds send a signal to COMsense, which in turn delivers a message to the VIController. The controller then flashes the lights.
COMsense can also be programmed to sense such things as air or water temperature, ground moisture, and humidity. With that type of information, the VIController would know to turn on the lawn sprinkler when the moisture level drops below a certain point or turn on the heater when the temperature falls.
Another Genesis product, the COMclock ($69.95), is a battery-powered, realtime clock which contains its own ROM chip. It connects to the Commodore 64 through the expansion port, and can automatically reboot the software used by the VIController if there is a power failure or interruption. Savergy's products are compatible with COMsense and COMclock.
For real do-it-yourselfers, another way to build a home security system is with transducers, says Coffron. Transducers sense physical information, such as a door being open, and send an electrical signal that the computer can understand.
Depending on what type of program you've designed for your security system, any one of a number of actions can be programmed: An alarm can sound, lights can start flashing, or your computer can automatically dial law enforcement authorities, via modem, alerting them to the break-in.
Software also can be used to schedule the times at which appliances and lights are turned on and off.
You don't have to be a mechanical genius to put such a system together, Coffron adds. "That had a lot to do with why I wrote the books," he says. "To show that you don't need to be a genius." Installing transducers and BSR modules is "a pretty straightforward kind of thing, and the wiring is like putting up speakers for your stereo—everybody takes that as a pretty mundane function," Coffron says.
But do you want to dedicate your computer to just controlling your home?
An alternative many people opt for is to buy a relatively inexpensive machine, such as the VIC-20 or Commodore 64, and use it solely for home control. Coffron says he designed the systems diagrammed in his books to be used at times when the computer was not needed for other functions.
With the VIController, the computer can be used for other programs, once the time-of-day scheduling software is up and running, says Randy Brust, vice president of Genesis.
The High-End Future
For people interested in an entire home control system, there are several high-end products which come complete with their own microprocessors. While their costs are significantly higher, they point the way to what will surely be the home control formats of the future.
Electronic Systems International has introduced the $898 Savlt Lifestyle energy control computer, which monitors heat and air conditioning use. The system can reportedly save up to 42 percent on a home's or small business's annual heating and cooling costs.
The computer electronically senses the temperature, as well as temperature changes. It checks the temperature every 1-1/2 seconds, and automatically adjusts the heating and air conditioning for different times of the day.
Another control package, the HomeBrain Intelligence System, controls and monitors energy consumption, security and fire safety, environment, and lighting and appliances. Produced by HyperTek Incorporated, HomeBrain lets you program the variables you desire for temperature and light sensors, sirens, switches, and motion sensors. Once these are set, a personal computer isn't needed with HomeBrain. The unit's CPU takes care of the rest. Up to 300 different switch-controllable devices can be hooked up to HomeBrain, although not all simultaneously.
The Powerport from Savergy, Inc., plugs into the user port of a Commodore 64 to control appliances.
The system has a variety of subtle monitoring formats. For example, a rain sensor can make sure that the lawn is not watered during a rainstorm. Motion detectors can tell when the house is empty, so that heat or air conditioning won't run needlessly when no one's home.
At $1499 suggested retail, the HomeBrain system isn't cheap. The manufacturers estimate a three- to five-year payback, with energy savings of 10 to 30 percent.
HyperTek also makes an enhanced package, complete with software and peripherals, which retails for $2149. That system is preprogrammed for a typical house, says Eric Davidson, director of marketing at HyperTek.
That Warm Feeling
Brust and Coffron agree that one of the most popular uses for computer control devices is home security. It offers an intangible psychological benefit, Coffron says—peace of mind.
"It gives you a warm feeling that everything is as it should be."
While it may be a some-what exacting process to start a computer-based home control system from scratch, both Coffron and Brayden foresee a time when houses will be built with computers already installed.
Blauvelt, NY 10913
Electronic Systems International
2797 Peterson Place
Norcross, GA 30071
Genesis Computer Corporation
P.O. Box 1143
Bethlehem, PA 18018
Salem Industrial Park
P.O. Box 137, Route 22 East Whitehorse, NJ 08888
Leviton Manufacturing Co.
5925 Little Neck Parkway
Little Neck, NY 11362
1404 Webster Avenue
Fort Collins, CO 80524
For the books The IBM PC Connection, The VIC Connection, The Apple Connection, and The Commodore 64 Connection, by James Coffron, contact:
2344 Sixth Street
Berkeley, CA 94710
"I firmly believe that within five to ten years, builders will start building a computer nook into a home, and at that point, it becomes very feasible to have your so-called black box [controller] sitting next to that home computer," Brayden says.
Coffron predicts that homes in the not too distant future will have computer jacks in every room, the way electrical outlets and telephone jacks are commonplace now. Along with the jacks, "there will be interfaces for whatever computer you have, and they'll be tied in to wiring all over your house, so you really won't have to do anything but run your home security package, or run your home control package."