Zoning Return on Investment – Payback?
There is no short answer to this question with Zone Control. Energy CAN be saved with zoning but it is also capable of increasing the comfort of a home. Because of this, a zoning system can both save and cost energy depending on how the homeowner uses it. User habits of operating the system primarily determine how much energy will be used or saved. An example would be a homeowner that very carefully controls the thermostats of his system (turning off zones when not in use) will be able to realize more energy savings than someone who does simply sets all zones for a comfortable temperature.
Several years ago, a typical homeowner would not have wanted to bother with several different thermostats to save only a few dollars a month. Today is a different story. We are more energy conscience and actually demand greater control. Zoning allows this control and lets the user balance the comfort and efficiency levels that are right for them.
The user (homeowner) can save energy by taking advantage of the superior control capabilities that zoning provides and putting thermostats in rooms that are not being used in a setback temperature (or OFF). On the other hand, if operated by the end-user improperly, it will not save energy. Homeowner involvement is absolutely necessary for energy savings to be seen with a zoning system. It is intuitive to a user how to enjoy the COMFORT features of zoning. Simply set the thermostats to the temperature that makes you comfortable. But the energy savings features of zoning can be less obvious.
Most manufactures of zoning products & independant studies quote 20 to 35% savings of the HVAC energy usage “CAN” be seen with zoning. The higher end of this range is the case where the user has chosen to operate the system to maximize savings.
Like most good things come with a cost… The cost of zoning hardware is not more than a few hundred dollars, however efficiency can have other costs... comfort or convenience. If a homeowner turns OFF lights in every room that is not being used, then more energy can be saved but it can be less convenient than just leaving all the lights on. With zoning, the added control can be useful and helpful but it can become an inconvenience for some.
Some Zoning Products have built-in features that improve energy saving capability. SmartZone from ECOJAY has “ECO Mode” that allows setback of the whole system from one thermostat for easier control. Also, SmartZone has a potential of saving energy automatically on 2 stage systems. Using the built in temp sensor, SmartZone only turns on 2nd stage when needed. Turning on 2nd stage when not needed (which most all thermostat do) can waste 1000s of kWh and can reduce the life of your equipment. Another energy-saving feature of SmartZone-4X is economizer, AC run-time can be reduced on mild temperature days with the use of an outdoor temp sensor.
There are too many uncontrollable variables to give a make a calculation of exactly how much energy could be saved in a particular situation. These variables include the wide range of different possible installation applications due to the on-site circumstances that can create additional installation cost & reduce energy saving potential.
With zoning it is possible to achieve a perfect mix of comfort and efficiency with the correct equipment and proper operation of the system. This mix can be adjusted by user’s operation of the system. Zoning does not save energy or make an area comfortable by itself, it is only a tool that provides the ability for the user to set the exact mix that meets his needs.
Light switches don’t save energy… turning the light switch OFF saves energy.
Although ZONING itself does not provide energy savings, it gives the user the ability to achieve greater efficiency with more granular control of the load. This simply means that BOTH energy savings and better comfort can be achieved with HVAC Zoning.