The challenge The filter element is an essential component of any ventilation system, since it is designed to remove airborne contaminants, which can be either chemical or biological. Ever-increasing air pollution and the ongoing publications on the negative effects it has on human health (see the latest WHO report of 12/05/16) are constantly drawing the attention of regulators and citizens, who increasingly consider the quality of the air we breathe indoors as one of the necessary conditions for well-being. The key factors to achieve high air quality are ventilation (quantity) and filtration (efficiency), which are typically in contrast with energy savings, an aspect regulated by all governments. Despite the fact that these requirements are in stark contrast with one another, active electrostatic filtration appears to be the only solution that dramatically reduces energy consumption, increases filtration efficiency and prevents the proliferation of the microbial load, either in the air or deposited.The Sabiana solution Sabiana has developed an active electrostatic filter with modular units (Crystall) that maintains all the distinctive features of electrostatic technology, turning some typically negative aspects into operational benefits.This new solution features two separate and distinct sections, using different construction technology, each with its own functional purposes. The first section, defined as an active section or polarisation, is an integral part of the supporting structure and consists of thread-like tungsten emission electrodes, whose design ensures reliability and safety without using special, delicate and expensive materials (isolators).The second section, called a passive section with an induced or collection anode, consists of laminated aluminum profiles that are placed opposite to each other and suitably spaced out. They create an electric field without applying an additional power source, thus ensuring they can be removed for maintenance purposes (cleaning).Thanks to this technology, each area of the collector is autonomous, thus avoiding any accidental short-circuits on one section that may affect the operation of the entire filter. Benefits In general, mechanical filters increase filtration efficiency according to the pressure drops (the newer they are, the less they filter), thus ensuring the class they belong to (average efficiency) only after a certain period of operation with a significant impact on energy consumption. Instead, the use of an electrostatic filtering system such as “Crystall” offers a series ofbenefits, which are listed here below. • Guaranteed energy savings (80% less than F9 Eurovent A+) due to negligible pressure drops that are constant over time (< 30 Pa);• High filtration eiciency (> 97%) also with a clean filter;• Capacity to filter very small particles (< 0.01 μm);• Slower fan rotation speed resulting in lower noise levels;• Constant input air flow when filters get dirty;• Proven bactericidal action resulting in a reduction of the causes of the “Sick building syndrome”;• Simple and inexpensive maintenance through washing only with water and a normal, biodegradable detergent;• Certification according to UNI 11254:2007;• Technologically sustainable and patented solution Applications The Crystall active electrostatic filter is an exclusive solution by Sabiana, designed to be applied on both air handling units and terminal units, significantly improving air quality and drastically reducing energy consumption without compromising thermal performance.The standard sizes, which match those used in the field of mechanical filters, and a limited depth of just 100 mm mean it can be easily used not only on new air handling units, but also on existing ones manufactured by Sabiana or other manufacturers.With the publication of European standard EN 13779, the concept of performance was introduced (control of specific pollutants to obtain concentration levels below imposed limits), which does not pose any restrictions to the plant solution to be adopted, allowing the designer to achieve the desired air quality. To do so, works do not just involve the outdoor air input, but also and more importantly, secondary air handling – as long as one uses filtering systems that ensure a quality comparable to that of outdoor air.By improving the filtration efficiency of the internal terminal units, one can decrease the volume of outdoor air to the minimum permitted values.With its Carisma fan coils and SkyStar cassettes, Sabiana offers an active electrostatic filter option, thus allowing for reduced initial investment costs and lower energy consumption during operation. Sabiana SpASabiana SpA is one of the leading companies in Europe in the field of air-conditioning, whose excellence, in terms of professionalism, solidity, reliability and technological know-how is universally acknowledged.This level of excellence has allowed it, starting from 1 July 2014, to join the AFG group, Arbonia-Forster-Holding AG, an international group and technological leader in the production of materials for construction, which operates worldwide and owns more than 40 distribution companies, with representatives and partners active in more than 70 countries.Today, Sabiana’s production ranges from air-conditioning systems for major industries to those for single residential units.