ACR Journal

CMYK / .ai CMYK / .ai CMYK / .ai acrjournal.uk 25 AIR FILTRATION or gaseous contaminants from the outside then a requirement for molecular filtration systems would be advised to ensure adequate protection for residents. Another consideration that is important in these systems is energy consumption. To manage the energy consumption of your air filters there is a Eurovent standard 4/21 that rates your air filter from A+ to E classification. These classifications are important to consider, especially when the requirement for Net Carbon Zero continues to grow. Air filtration requirements for recirculation air systems Over the course of COVID-19 we have seen many regulations and guidelines issued, expressing that recirculation air systems should be turned o†, with the exception being only if these units are utilising HEPA filtration. The reason for this is that recirculating air systems, that do not use HEPA air filters, can often spread viruses from one location to other areas or redistribute contaminated air back into the room causing further outbreaks. The problem here is that not all systems are made to accommodate HEPA air filters. Often the increased pressure drop will either not be permitted by the fan or a reduction in air supply will occur. As a result, it is important to ensure your system is properly protected. For instance, if your recirculation air mixes through your supply air system you could be safely operate it with installing an ePM1 60% bag filter in the exhaust air, then with two further stages in the supply air system of ePM1 60% your final filtration performance will be somewhere in the region of 95%. This can often be a simple upgrade producing maximum benefit. Air filtration requirements for air purification systems If we examine WHO recommendations and government guidelines we see that one technology is often mentioned, HEPA filtration. HEPA filtration has been used for years to protect people from airborne contamination risks. But what exactly is a HEPA filter? I think it’s best described as a tested and certified filter that performs at 99.95%(H13) or 99.995%(H14) ešciency. When choosing a HEPA air purifier there are a number of important considerations, such as: 1. Is the HEPA filter individually tested and certified to EN1822:2019 standard? 2. Is the unit sized adequately for the space? REHVA recommends that air purifiers are sized to achieve between 2 and 5 air changes in your environment. 3. Does the system create any bi-products? Some air purifiers that use other technology can create ozone. Check that 0% emissions are created by your system. These are just some of the key metrics and considerations to bear in mind when assessing the viability of air filtration systems for any building in a post- pandemic world. https://www.camfil.com/en-ie/