SMART BUILDINGS | VENTILATION and integration with electric grid control strategies. Smart systems can have sensors to detect airflow, pressures or fan energy use so system failures can be detected and repaired and when components need maintenance. Contributor to smart buildings AIR OF INTELLIGENCE What is smart ventilation? The University of Nottinghams Benjamin Jones looks at the definition given by the Air Infiltration and Ventilation Centre F or many building systems, claiming to be smart has technological and commercial advantages. In March 2017, a working group of Air Infiltration and Ventilation Centre (AIVC) experts from several countries agreed that smart ventilation is a process to continually adjust the ventilation system in time and, optionally, by location to provide desired indoor air quality (IAQ) benefits while minimising energy consumption, utility bills and other non-IAQ costs (such as thermal discomfort or noise). A smart system adjusts ventilation rates to: occupancy; outdoor thermal and air-quality conditions; electricity grid needs; direct sensing of contaminants; and operation of other air-moving and air-cleaning systems. It can supply information on operational energy consumption and IAQ to building owners, occupants and managers, and signal when systems need maintenance or repair. A smart system can adjust ventilation depending on demand for example, if the building is empty. It can also time-shift ventilation to periods when: a) indoor-outdoor temperature differences are smaller (and away from peak outdoor temperatures and humidity); b) indoor-outdoor temperatures are appropriate for ventilative cooling; or c) outdoor air quality is acceptable. Being responsive to the electricity grid needs means providing flexibility to electricity demand including direct signals from utilities Provides IAQ Improves thermal comfort Smart ventilation requires a more complex system than one without controls. This additional complexity is needed to get smart ventilation including electricity grid interaction or controls, depending on outdoor conditions to optimise energy use without compromising IAQ. This increased integration of the ventilation system environment in its control strategy is part of the trend towards smart buildings. It is made possible because of the progress made on sensors, and on information and communication technologies. In the proposal for a revised Directive on the Energy Performance of Buildings, the European Commission citing the need to define a smartness indicator explained that the smartness of a building covers flexibility features, enhanced functionalities and capabilities resulting from more interconnected and built-in intelligent devices being integrated into the conventional technical building systems. The features shall enhance the ability of occupants and the building itself to react to comfort or operational requirements, take part in demand response and contribute to the optimum, smooth and safe operation of the various energy systems and district infrastructures to which the building is connected. Although this mainly refers to energy, it is clear that smart ventilation is a key contributor to the smart readiness of buildings for reducing energy impacts and providing IAQ. Standards and regulations Europe In the standards that support the Energy performance of buildings directive (EPBD), smart ventilation can be considered using the control parameter ctrl, defined in the European Standard EN 16798-7:2017. But this standard offers little information on how to determine this characteristic for specific systems. Continually adjusts ventilation system SMART VENTILATION Minimises utility bills Minimises energy consumption Minimises noise Main features of smart ventilation 62 September 2019 www.cibsejournal.com CIBSE Sep19 pp62-63 Smart vent.indd 62 23/08/2019 15:17