Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, July 11, 1995 TAG: 9507110028
SECTION: EXTRA PAGE: 3 EDITION: METRO
SOURCE: DAVID BUTLER
DATELINE: LENGTH: Medium
A: There are several ways to solve this problem. The product you mentioned is basically a small heating element that "tricks" a thermostat into setback. The element mounts below the thermostat and plugs into a special power line carrier (PLC) appliance module. The PLC module allows the element to be remotely activated from a wireless hand-held remote or a 24-hour timer.
Unfortunately, you're right about the minimum adjustment. The heating element has three setback modes: five, ten and fifteen degrees. For example, if you wanted to reduce the nighttime temperature from 72 to 62 degrees, you'd set the stat to 72 and select the ten-degree setting on the element. Just reverse the procedure during the summer. At best, this approach yields only approximate results.
Several companies have introduced thermostats with special provisions for an external controller. For example, one company's extensive line of digital thermostats can be toggled in and out of setback from an external switch. Using a low-voltage PLC module as the external switch, you can activate or deactivate the setback mode from any room in the house.
However, no thermostat has been capable of full remote control - until now. You can finally get a digital thermostat that's compatible with popular PLC home control products. Using an inexpensive plug-in control console or a hand-held remote, you can set the temperature from 62 to 84 degrees (in one-degree increments) or select the operating mode (heat/cool/auto).
Another company recently introduced an extensive line of thermostats equipped with a serial port. Like other programmable stats, you can set four schedules per day from the stat's keypad. However, the serial port makes it possible to connect the stat to a personal computer or home automation system. Using special software, you can monitor the temperature or enter new schedules - all from your PC!
A Canadian company has taken a different approach. Its modular line of smart thermostats is designed especially for electric baseboard and radiant heat. One version includes a wireless remote; another assists the user with its synthesized voice - ideal for someone with impaired vision. The original model features a built-in motion sensor that cancels the setback mode when someone enters the room.
Conventional thermostats also offer some interesting new features. For example, several models offer filter and energy monitors (based on actual run-time). If you like the idea of a setback stat but you're turned off by the idea of entering temperatures and schedules, you'll appreciate the simplicity of a pre-programmed stat. All you have to do is review a list of daily schedule and temperature settings and select one that suits your lifestyle.
A growing number of thermostats will accept remote temperature sensors. This option allows you to mount the stat wherever you choose - in the kitchen or hidden away in a closet. The unobtrusive sensor replaces the stat in its traditional location: away from drafts, direct sunlight and exterior walls.
To receive a manufacturer source list for the programmable thermostats and controls mentioned in this article, send $1.50 (please don't send cash) and a self-addressed envelope to David Butler F-520, Department TWN, 14713 Pleasant Hill Road, Charlotte, N.C. 28278-7927. The list includes toll-free phone numbers and a summary of each company's products.
TechTalk: When connecting a remote temperature sensor to a thermostat, it's important to use shielded cable with a "drain" wire (similar to microphone cable). This helps to reduce interference from nearby electrical appliances and wiring. The latest generation of remote temperature sensors is fully digital, virtually eliminating the potential for measurement errors.
by CNB