Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, August 8, 1995 TAG: 9508080081
SECTION: EXTRA PAGE: 3 EDITION: METRO
SOURCE: DAVID BUTLER
DATELINE: LENGTH: Medium
A: Conventional heating and cooling systems use a single thermostat to control the temperature for the entire home. But these systems can't eliminate hot and cold spots. In single-level homes, the sun heats rooms on one side, while others may become too cool. In multilevel homes, temperature variations are compounded by warm air's natural tendency to rise.
Some rooms may be difficult to regulate no matter what season it is - possibly because they're isolated from the rest of the house or near the end of the duct system. Or you may have an unused bedroom that you'd prefer not to cool. A single-thermostat system can't do this.
A multizone heating and cooling system can correct these problems by dividing your home into individual comfort zones. For example, a two-zone system typically separates the living area from the sleeping area (or the upstairs from the downstairs), allowing you to optimize comfort throughout your home. You can set the temperature in one area without affecting the other.
Here's how it works: One thermostat tracks the temperature in the living area. Another tracks the temperature in the sleeping area. Both connect to a control panel, which in turn, opens and shuts a series of motorized dampers inside the duct system. A small motor on the side of each damper rotates a blade, blocking the flow of conditioned air to that zone.
Zoned systems can be combined with programmable thermostats to automatically adjust the temperature while you're at work or while you're sleeping. Each zone can have its own setback schedule. Comfort is delivered not only where you need it, but when you need it.
Although installation is easiest during construction, you may be able to install a simple two-zone system in your existing home. Installation of the second thermostat and control panel is usually no problem. However, retrofitting motorized dampers can be easy, difficult or impossible - depending on the layout of your duct system.
If your home has inaccessible ductwork, inflatable dampers may be the answer. They're designed to slip into the duct just behind the register. An aquarium-type air pump relies on a series of electronic valves to inflate the proper damper. The damper expands like a balloon, blocking airflow into the room. Getting an air tube to each damper is usually the biggest installation challenge.
If you have a PC, you may be interested in a new temperature management program. Designed to work with a line of new digital thermostats, this PC-based software can also be linked to other automation systems. When combined with a zoned system, the software allows you to set temperatures or modify setback schedules without having to visit each thermostat.
For example, you can set up the software so that all thermostats will switch to setback mode when you arm your security system. Linked with motion detectors, control becomes even more automatic: You can program the software to adjust the temperature whenever someone walks into a room.
To receive a list of companies that manufacture automatic dampers and zone control systems, please send $1.50 (please don't send cash) and a self-addressed envelope to David Butler F-524, 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.
HomeTech News: According to The Gas Research Institute, a modulating (variable) gas furnace is under development. Expected to be introduced in 1996, the furnace will feature an advanced control system that will include a home automation interface (CEBus) along with support eight temperature zones. With variable output, the furnace can easily adapt to current conditions, including the number of zones calling for heat.
by CNB