However, there are considerations to think about if you're discussing an area. Another factor in keeping the temperature of an area under control are the devices that are within that area. Units that produce heat, such as stoves and fireplaces, will eliminate all the temperature in the home in a standard HVAC system. With a zoned system, the kitchen or living room can be adjusted separately from the other living areas to eliminate this problem.
For example, suppose that you are going to be using the oven for an extended period of time. In that case, you can lower the kitchen temperature to keep the area comfortable even when the oven is turned on. For an HVAC zoning system to work with existing HVAC equipment that isn't divided into zones, it must have at least two-stage (high and low) or modulating (multi-stage) equipment. Your options are a single HVAC system divided into two zones, as we've been discussing, or two separate HVAC systems, one for each level of the house.
A zoned system is a single HVAC system that serves two or more zones, rather than two separate HVAC systems.
