Zoning in HVAC Systems
One of the more overlooked aspects of home automation is the inclusion of area zoning in HVAC system design. Zoning eliminates the need for multiple systems and will maximize energy savings while improving indoor comfort.
In new construction, the HVAC system designer faces the challenge of maintaining a suitable temperature and humidity level in rooms with significantly different load requirements. Two story homes are particularly difficult because of the air stratification effect. Glass exposure, insulation levels and duct leakage also serve to complicate load calculations and the design of the duct network.
True zoning relies on a single heating and cooling system and a network of relays, powered dampers, zone controllers and communicating thermostats.
At the heart of the process, the zone control module is hard wired to a series of mechanized dampers. After the primary duct trunk line is installed, the dampers are strategically inserted in the secondary run outs. The devices are 24-VAC, spring loaded and motorized. The dampers open and close to supply or restrict the movement of conditioned air depending on the thermostat call in a particular zone. In essence, family members have the ability to tailor the temperature in each room to meet their own personal preferences.
Zoning systems are compatible with virtually any digital or programmable thermostat, so the full array of features can be utilized. This includes a variety of setback programs that adjust the indoor temperature to maximize energy savings when the building is unoccupied. Homeowners can adjust the temperature remotely so the building is returned to the appropriate comfort zone just prior to the arrival of the first family member.
How HVAC Zoning Systems Operate
The actual operation of the zoning system begins when a local thermostat calls for heating or cooling. A relay is closed, and the control panel opens the appropriate damper for the targeted zone. The condensing unit is engaged, and conditioned air is directed to the area of need.
If there is a signal from another zone during the cycle, its damper will immediately open. The process of opening and closing dampers continues until the different thermostats report that the all of the zones are satisfied. Excess cooled or heated air is then directed to the last zone that called for it, and the condensing unit is instructed to shut down.
Zoning and Home Automation
HVAC zoning systems are extremely flexible. Instructions can be input in a variety of ways including a thermostat, PC, smart phone or mobile device. Communicating thermostats can be integrated with lighting, security, audio/video and other appliances. Additionally, many of today’s advanced thermostats comply with existing wireless protocols such as X-10, Insteon, Z-wave and Zigbee.
Zoning is a perfect alternative for homes and buildings requiring multiple independent heating and cooling systems. The initial installed costs will be significantly lower since the requirement for additional equipment is eliminated. Zoning can be easily combined with modern home automation systems to provide enhanced comfort, exceptional efficiency and a longer equipment lifecycle.