Article on a paper titled ‘Filtering Airborne Aspergillosis’ by Don Donovan – Camfil Farr Ireland
There is much written about the prevention of Nosocomial Invasive Aspergillosis, how outbreaks can happen and the effect that it can have in immune suppressed patients.
While this paper looks briefly at Aspergillous its main focus considers filtration steps to prevent airborne Aspergillus entering the hospital ventilation systems but as requested it will also consider other fungi spores in its recommendation.
Many commentators have suggested that HEPA (High Efficiency Particle Air) filters should be installed as a final stage of filtration and this has now been written into many hospital guidelines and standards. This document will review this in more detail.
In compiling this report I felt it was worthwhile taken into account the general indoor air quality and how it can be improved by the installing the optimum filter selection while at the same time taking into account the cost of energy, labour and waste disposal.
In most cases the particle size of different contaminant are known however to understand how these particles are actually filtered this document includes a section on the principles of filtration.
Over the years, many of the standards and regulations that govern air filters have been updated, and this document will review these and look at why they have changed for the better. The new standards have more emphasis now on the protecting of people’s health (IAQ) and the conservation of Energy. At the end of this report recommendations are put forward. READ THE FULL REPORT HERE.
Hospital IAQ Related articles:
Operating theatres require a much cleaner level of air than general areas, so they would be expected to have HEPA filtration for invasive surgery. H14 class filters are the usual particulate efficiency for these Ultra-Clean Ventilation systems.
The Chartered Institute of Building Service Engineers (CIBSE) offer guidance in their CIBSE Guide A on Environmental design of F7-F9 class air filters for use hospital wards. They also advise F7 class for offices. This chimes well with the advised filter class of minimum F7 and recommended F9 in EN13779:2007 Performance requirements for ventilation and room conditioning in non-residential buildings.