Page 220 - Alternative Energy Systems in Building Design

196 ENERGY CONSERVATION

■ The ability to control of HVAC system components
■ The ability to read and store data and display them on electric, gas, and water meters
■ The ability to provide remote-control monitoring and programming using a variety
of communication technologies
■ The ability to provide local and remote alarm reporting
■ The ability to manage and control local or remote demand-side loads

The system also must produce a high rate of internally verifiable energy savings in
commercial and residential applications. In essence, the energy-management system must
optimize HVAC energy efficiency by causing the equipment to operate in an energy-
recovery mode for a significant portion of each cooling or heating cycle without affecting
the comfort zone of the facility. The system also must be able to reduce energy con-
sumption and demand by programming the HVAC equipment to cool or heat the facility
on an optimal schedule. Typically, a well-designed centralized energy-management
system also must incorporate software features to remotely program, control, and perform
energy analyses of the utility demand-side loads. In essence, the significance of a
centralized energy-management and control systems (CEMCS) is to enable cost savings
through improved efficiency and operational and maintenance savings while allowing the
utility to implement real-time demand-side management on a local or remote basis.

UTILITY DEMAND-SIDE MANAGEMENT

In centralized energy-management systems, utility demand-side management (DSM) is
achieved by programmed efficient loading and operation of the HVAC equipment. Real-
time DSM is achieved by allowing a utility to control the setpoint temperature used for
either air-conditioning or heating on a local and remote basis through two-way modem
communications or optionally with a radiofrequency paging system. The control
setpoints also can be proportionally or continuously controlled and changed by the
utility as the demand for electric power increases or decreases. The energy-management
systems in general can be programmed to raise the cooling or heating setpoint tempera-
ture in small increments, cycle units on a timed operational basis, or shut units off while
the system’s data-acquisition aspect automatically provides display and reporting of
changes and load-shedding capability to the utility via modem communications.

CONSUMER ELECTRICAL DEMAND SAVINGS
Consumers with single or multiple HVAC systems can achieve electrical demand
savings by the programmed use of the centralized sequencing of the operation of multiple
air-conditioning systems to limit the number of air-conditioner compressors operating
at any one time. The utility/consumer also can place setpoint limits on the amount the
room temperature can rise during DSM load-shedding control in cooling and establish
priorities for unloading each HVAC system.

ENERGY CONSERVATION
Energy conservation is achieved by programming the centralized energy-management
systems for more energy-efficient temperature settings for heating and cooling at all