With the conclusion of last year’s United Nations Climate Change Conference in Paris, energy regulators are paying a lot more attention to buildings’ efficiency performance, going forward. Buildings will need to become ever-more efficient, if the countries that signed the Paris agreement are going to reach their agreed-upon CO2-reduction targets. Engineers and building owners in the European Union (EU) have a head start, in this regard, thanks to longstanding recognition of the importance of building efficiency, which has led to the development of tools to help quantify and improve energy performance.
Europe-wide energy standards have been in effect since 2002, when the Energy Performance of Buildings Directive was enacted across the EU. This directive requires member nations to set minimum energy-performance requirements for both residential and non-residential buildings, and to establish means for measuring that performance. One method published in 2012, the European Standard EN 15232: “Energy performance of buildings – impact of Building Automation, Controls and Building Management,” can help owners and engineers assess how much impact today’s increasingly sophisticated building automation and control systems (BACS) can have on energy performance and use in a specific building.
Similar to a number of other European energy standards – including the International Electrotechnical Commission’s Standard 60634: “Electrical energy efficiency within low-voltage settings,” which I’ve covered in previous posts, “IEC 60364-8-1: Setting a New Standard for Efficient Buildings,” and “IEC 60364-8-1 – A Systematic Guideline to Continual Assessment of Building Energy Efficiency,” EN 15232 is a point-based system that provides concrete means for assessing, in this case, BACS performance. In addition to benchmarking such systems in existing system, this newer standard can help engineers and building developers work together to determine the functionality required in new facilities based on efficiency goals and budgets.
The standard provides a detailed table outlining performance characteristics in a broad range of categories, with related scoring that rises according to impact on energy efficiency. As an example, Table 1 illustrates the scoring outlined in the standard’s Table 1 related to the level of control of a building’s heating system.As you can see, the simple four-step progression for this category moves from no automatic control of room temperatures to individual room control with communication to a central system and some sort of occupancy sensing.
By doing this kind of inventory for all building energy systems either in place or planned, engineers can determine into which of four efficiency classes the BACS will fall, as follows:
- Class D – non-energy-efficient BACS. Buildings with Class D systems should be retrofitted, and new buildings should not be built with such systems.
- Class C – the base or benchmark level of acceptable BACS, and includes (among other provisions) room-level manual controls for climate and lighting controls, along with some room-level time-dependent ventilation. Window blinds feature motorized operation with manual control.
- Class B – the first tier of improvement from the base acceptable level, with features that include individual room-level heating and cooling control with some central-system communication, room-level time-dependent air-flow control and automatic occupancy detection for lighting.
- Class A – the highest level of automation, including centralized communication of room-level temperature controls, presence-dependent air-flow control, and automatic daylight control that ties together operation of lighting, motorized blinds and climate controls.
So, what is the added value to owners of moving up to more efficient BACS installations? The standard’s Table 5 illustrates the potential impact in just one aspect of building energy use – the energy consumed in thermal performance – for a range of nonresidential occupancy types. As you can see, with Class C designs as the benchmark, office buildings could see a 30 percent reduction in related energy use by adopting high-efficiency equipment.
Schneider Electric’s Smart Panels and Enerlin’X communications systems can connect with onsite energy-management systems to provide the real-time and historical energy-use data that can be critical to ensuring BACS delivery their promised efficiency. And be sure to visit our Consulting Engineer Portal for a range of additional electrical-design resources and tools.