press release of Clivet S.p.A.

SARS-CoV-2: Clivet tecnology to reduce infection risk in confined spaces

Following the COVID-19 pandemic and the risk of contagion in public and private confined spaces, in view of the reopening to the public of shops, bars and restaurants Clivet reaffirms the importance of the role of air conditioning equipped with effective ventilation and air filtration systems to reduce the risk of contagion.

Feltre, 08th May 2020


For over 30 years, Clivet has been a reference company within the air conditioning industry. In this particular period characterised by the risk of contracting the SARS CoV-2 infection in confined spaces, Clivet emphasizes the important role that air conditioning systems can play for the containment of the virus spread, together with the other measures provided by governments.

It is well known that the contagion occurs by inhaling droplets produced by coughs and sneezes in cases of social distances lower than one/two meters, contact with contaminated surfaces, or inhaling faecal plumes from toilets.

Recent surveys show that infection risk increases when there are large amounts of aerosols, classified as PM10 PM2,5 and nanoparticles PM1 with dimensions respectively lower than 10 mm, 2,5 µm and 1 µm. SARS CoV-2 virus is on last category with a dimension between 0,08 µm and 0,16 µm.
Particles with larger dimensions coming from outdoor or indoor air can be a means of transport for the virus. Under ventilated, occupied spaces can increase the risk of infection.
Items that can decrease infection risk within occupied spaces, are the "air renewal rate" and the air filtration efficiency.

In confined spaces that do not have air-conditioning systems, ventilation can be achieved by the opening of windows (if possible). This does not guarantee air filtration and can cause occupant discomfort and energy waste. Without a constant rate of air renewal, there could also be an increased risk of infection.

This demonstrates the important role of a mechanical ventilation system, with controlled inlet of external purified and handled air and the extraction and expulsion of used air, above all during such a difficult pandemic.

ASHRAE, REHVA and national associations guidelines suggest to increase as much as possible the renewal air inlet in existing installations and to assure correct pressure differences to toilet extract systems.

Clivet has always paid close attention to the theme of the IAQ and over the years has developed innovative CMV (Controlled Mechanical Ventilation) and DOAS (Dedicated Outdoor Air Systems) particularly suitable for easy installation in bars, shops, large and medium-sized sales areas, and restaurants. These packaged high efficiency systems do not require to be fed with hot or chilled water or refrigerant gas.

Available with air flow rates from 125 m3/h to 14.000 m3/h, they allow heating, cooling and dehumidification to the renewal air, to automatically control flow rates, and to expel used air. They also utilise the energy contained in the exhaust air through a thermodynamic heat recovery system that allows to efficiently obtain thermo-frigorific powers much higher than those obtainable from conventional heat recovery systems, thus being able to satisfy independently also the thermal loads of cooling and heating during the mid-season. 

They have electronic filers that capture particles through an electrostatic field with minimum losses than can reduce the energy used by the fans. They also perform an ionizing action to the treated air, with an effective microbicidal action on bacteria and viruses. These filters are washable and do not require replacement.

Aware that each building has different air conditioning needs, Clivet offers several renewal and purification systems for commercial (ZEPHIR3) and residential (ELFOFresh2 and ELFOFresh EVO) applications, air handling units for hospitals, process industry, data centres (AQX and SAHU), full fresh air systems, air renewal and air-conditioning systems for medium and high attendance for commercial centres, multiplex cinemas, restaurants, kitchens … (rooftop CLIVETPack, SMARTPack). For houses with nearly zero energy need, Clivet offers an innovative packaged unit (ELFOPack) that renews and purifies the air, heats, cools and produces sanitary hot water.