Building Automation and Energy Efficiency (EN 15232 standard)

Automation, control, and supervision systems can have a significant impact on the energy consumption of buildings and their occupants, reducing it by 10, 20, or even more than 50 percent. In recognition of that fact and to encourage implementation of these systems, the European Committee for Standardization issued EN 15232 Standard: Energy Performance of Buildings – Impact of Building Automation, Controls, and Building Management for use in conjunction with their Energy Performance of Buildings Directive (EPBD). These documents define conventions and methods for estimating the impact of building automation and control systems (BACS) on the energy performance of building.

Focusing on EN 15232, in this paper, we present an overview of BACS, highlighting the advantages they can provide and describing the primary functions they can perform. Because a building energy audit is the first step in developing any energy management program, we describe the three different levels of complexity of such an audit before tackling the details of the EN 15232 BACS classification system and looking at some examples of BACS implementation schemes.

The actual savings in both energy usage and costs that a BACS can provide is of primary interest to building managers and owners as well as BACS system designers. We describe the two calculation methods presented within the Standard: the simple Method of Efficiency Factors, useful for obtaining a quick estimate, and the more rigorous Detailed Calculation method, which returns a more accurate result but requires much more information and effort. We also examine two different procedures for evaluating the costs associated with a BACS: the Payback method and Life-Cycle Cost Analysis.

Finally, we explore how the methods and classification system of EN 15232 work with those of the EPBD.