people in uk spend more than 80% of their time indoors, whether at home, at work, at school or on the go. That’s why it’s important to make sure the air inside those enclosed spaces is safe to breathe.
In recent years, there has been a wide range of air-cleaning devices on the market, especially once it became clear that COVID was an airborne disease. Some devices work by thermal or photocatalytic oxidation, others by adsorption, filtration, UV germicidal irradiation, ion generation, and electrostatic precipitation.
Despite their scientific-sounding names, none of these techniques remove all indoor air pollutants and many produce undesirable chemical pollutants, as a detailed recent report pointed out. report good by the UK government’s Scientific Advisory Group for Emergencies (Sage).
For example, ionizing devices give particulate matter an electrical charge that causes it to fall on surfaces, removing it from the air. However, they can also produce ozone through their operation. Electrostatic precipitation devices also charge particulate matter to remove it but can produce nitrogen oxides and ozone.
Chemical oxidation devices actually use an ozonizer or a mixture of chemicals to directly release ozone or other oxidants into the room. Given that ozone and nitrogen oxides are harmful gases, some of these devices are simply displacing one pollutant with another.
The Sage report concluded that air-cleaning technologies were likely to provide only limited benefit in places that were adequately ventilated and unless there were specific risks (such as a busy street outside, so natural ventilation should be given more importance). make difficult) was not necessary. The report also concluded that, if necessary, techniques using filtration or germicidal UV would be most beneficial if used correctly.
One problem with air-cleaning devices is that they are unregulated in the UK. Anyone purchasing such equipment has to rely on information provided by the manufacturer to determine how efficiently it removes pollutants.
Instruments are tested under carefully controlled laboratory conditions rather than in a typical, occupied building. The issue of secondary pollutant build-up is often not addressed, and advice on where air-cleaning equipment should be placed for best results is often absent.
The onus is heavily on the consumer to assess the benefits of air-cleaning technologies and which one they should choose.
make it easy for consumers
To make it easier for consumers, the government needs to create an accredited and independent organization to test these devices for safety and effectiveness. Testing must be performed in a realistic indoor environment to ensure that each appliance is safe to use and maintain as it ages.
And manufacturers should provide clear advice on how to operate and maintain their air-cleaning equipment. The operation and maintenance of these devices should be as simple as possible.
Manufacturers should also provide operating parameters, as they currently do for white goods such as fridges and cookers. The parameters would include things like noise (if the equipment is too noisy, there is a risk that people will turn it off), maintenance costs, the amount of space that can be cleaned, and the efficiency of pollutant removal. These should be provided in a standard checklist format, making it easy for consumers to compare devices.
Even with these changes, consumers will still need to consider whether indoor spaces or rooms really need air-cleaning technology. This is perhaps the trickiest aspect, given that many consumers will lack the expertise or equipment to determine whether they need to clean the air in their homes.
For most homes, natural ventilation is sufficient, especially after activities that lead to high indoor emissions such as cooking and cleaning. Using a cooker hood in the kitchen when cooking and an extractor fan when using the bathroom will also help. If a building is located on a busy road, it may be necessary to open windows on the other side of the building or outside during busy times.
A relatively inexpensive way to help homeowners assess whether they need air cleaning in addition to ventilation is to purchase a carbon dioxide monitor. recently report good Indicates that carbon dioxide concentrations are consistently above 1,500 parts per million, suggesting ventilation is poor and that cleaning the air may be beneficial.
Ultimately, cleaning the air will only be an interim solution. For most buildings, the best solution is to remove air pollutants from the outside and ensure there are enough windows to provide adequate ventilation.
Nicola CarslawProfessor, Indoor Air Chemistry, York University
This article is republished from Conversation Under Creative Commons Licence. read the original article,
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