Abstract: To anticipate potential failure of a temperature modification device (e.g., heating, ventilating and air conditioning equipment used in a commercial building), an efficiency value representing the ability of the temperature modification device to change temperature in a predetermined zone is repeatedly computed. When one of these values is computed, it is used in determining whether the ability of the temperature modification device to change temperature in the predetermined zone has deteriorated over time. This is done by comparing a current efficiency value with a previous efficiency value. In response to a determined deterioration exceeding a predetermined tolerance, a control signal for initiating inspection of the temperature modification device is communicated, thereby enabling the device to be serviced in response to a detected operating condition of the device and before actual failure of the device.

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.

Abstract: Power demand is monitored and temperature control effected in response. If monitored power demand is below a predetermined power demand limit, a selected desired temperature setpoint is used as the temperature to be attained. If monitored power demand is above the power demand limit, a modified temperature setpoint is used. The modified temperature setpoint preferably is determined to maintain a still comfortable temperature while also reducing power demand.