Historically, filters have been installed to reduce the build-up of particles deposited on HVAC equipment, which can reduce airflow and prevent heat transfer. However, in recent years, potential health benefits have been increasingly recognized as one of the main goals of filtration.
Particles in indoor air come from outdoor air and various indoor sources, including cooking, smoking, furnishings, office equipment, chemical reactions, and various biological sources such as molds, pests, mites, and occupants.
Air filtration in buildings can significantly reduce occupant exposure to particles from both outdoor and indoor air (recirculating air). While the health effects of indoor particles are poorly understood, high concentrations of particulates in outdoor air are strongly related to a variety of adverse health effects. The impact of particles on health is strongly related to particle size and particle size is closely related to filtration.
Other benefits of Whatman Venting Filter include dust reduction of interior surfaces as well as deposition and accumulation of organic matter on the surfaces of ventilation ducts, coils, and fans, thus reducing the potential for ventilation. microbiological growth in these places. The amount of particles removed by filtration depends on the airflow rate and the fraction of particles removed (depending on their size) as the air flows through the filter media.
Particle filtration technologies are well established and widely available. The efficiency with which the particles are removed by the filters in the HVAC systems varies considerably depending on the type of filter used as well as the particle size. In Whatman making Standard, filters are listed in 20 MERV (Minimum Efficiency Reporting Value) classes according to their effectiveness in eliminating the different particle sizes. Therefore, the efficiency at which the particles are removed by the filters in the HVAC systems varies considerably depending on the type of filter used and the particle size. A higher MERV indicates greater efficiency in removing small particles, the most harmful to health. Currently, most HVAC systems in commercial and residential buildings have filters with relatively low efficiency (low efficiency for removing small particles). Therefore and in order to reduce adverse health effects, particle filtration in buildings needs to be improved. The additional costs of using higher efficiency filters and the expected health benefits are considerable. Therefore, the systematic use of high-efficiency filters in HVAC systems is good practice.
AIR FILTRATION AND OCCUPANT HEALTH
Several health effects are related to particle exposure that can be reduced by filtration. Allergies and asthma symptoms can occur in sensitive individuals when inhaling allergenic particles, such as pet allergens, dust mite allergens, pollens and fungal spores from outside or inside sources.
Extensive research indicates that asthma exacerbations, hospitalizations, and mortality rates increase with increasing particulate concentrations in outdoor air. Much of the exposure to outdoor air particles occurs when people are indoors and these exposures can be reduced by air filtration. Therefore, it is reasonable to expect health benefits from outdoor air filtration that significantly reduces the concentration of particles inside buildings.
Given the amount of time people spend indoors, indoor concentrations of particles of outdoor air origin and respiration rate, it is estimated that about 65% of inhalation of air particles outside occurs when people are inside. Therefore, an improvement in particle filtration systems in buildings reduces these exposures and consequently the associated premature morbidity and mortality.
The cost of filtration increases when high-efficiency filters are used, but it is not necessary to use filters with very high efficiency to significantly reduce the concentrations of particles in the interior; the cost increase associated with adequate filtration is therefore relatively modest.
However, filtration is only effective if the filters are replaced frequently and the ventilation system is properly maintained. Particle filters are an important source of air pollution.