Abstract: Control data to change any of various parameters in energy management systems that control energy consumption devices, such as heating and air conditioning equipment, is transmitted from a remote location, through a paging network, to a plurality of paging data receivers connected to respective energy management systems. The paging data receivers respond to a common call and pass the accompanying control data to their respective energy management systems, which individually react depending on whether one or more predetermined addresses is/are within the control data. A response to the remote site can be provided by an energy management system through the commercial telephone network.