Can air purifiers prevent asthma symptoms from getting worse?
Room air cleaners remove the smallest particles that are in the air within the device. However, air purifiers are not able to remove the particles of allergens caused by local sources of environmental pollution, for example, the waste products of microscopic dust mites that cloud up above the pillow when you flop on it (or when you just toss and turn in the bed).
You inhale these allergens before they get into the field of action of the air cleaner. The air cleaner needs 10-15 minutes to clean the room from such temporary hotbeds of dust and allergens.
Wall carpets – another powerful source of allergens, from which it is impossible to get rid of one vacuum cleaner or air cleaner. Accumulated allergens remain in the carpet until they are disturbed. When you vacuum the carpet, even using a good brush, a large amount of the allergen is thrown into the room, even if a highly efficient vacuum cleaner is running at that time. Room air cleaners are also less effective if the source of allergens is in the house, for example, a cat, dog, bird or hamster.
The effect of room air purifiers applies only to the room where they are located. Since about eight hours you spend in the bedroom, so according to the logic of things this is the first place where the air cleaner should be installed. In addition, you spend several hours a day in the kitchen and in the hall or office, so you need a separate air purifier for each of these rooms.
Types of air cleaners
There are many different types of air cleaners, including the following:
In mechanical air purifiers, a fan is used to force air through a special screen that captures the smallest particles, such as smoke, pollen, and other allergens in the air.
Highly efficient dust collector (VEPU) – one of the most famous air purifiers. VEPU (which means filter type, but not a brand name) was developed during World War II to prevent the spread of radioactive substances outside the laboratories. This air cleaner is capable of capturing up to 90% of all particles with a size of 0.3 microns or more. The disadvantage of this device is a noisy fan and a large consumption of electricity required for the operation of the device’s engine. Noise can be reduced by using a large device designed for large rooms, and turning it on at low speed. It is not recommended to direct the fan to carpets or curtains, as it may stir dust from carpets and curtains.
In addition, Ultra-VEPU is available, which capture very small dust particles. There is no evidence that these devices help to control asthma more effectively than with traditional VEPU.
The electric air purifiers use an electrical charge to attract and trap allergens and irritants. If the device consists of collecting plate electrodes, the particles circulate inside the system; otherwise, they stick to the surfaces of objects in the room and must be mechanically removed (wipe with a damp cloth). The disadvantage of such devices is the formation of a small amount of ozone. Ozone irritates the airways, causing temporary bronchospasm in asthmatics and a “stuffy nose” in people suffering from hay fever or rhinitis.
The hybrid air cleaner contains elements of mechanical and electric air cleaners.
Gas phase (GF) air cleaner uses activated carbon grain to remove odors (volatile organic compounds) and non-dispersed contaminants, such as cooking smells, paint smells or building materials (for example, formaldehyde) and perfume smells. These are black thin filter plates that are installed in front of the VEPU. The disadvantage of these filters is fragility, since they absorb smoke and odors and therefore they need to be changed at least once a month. And, nevertheless, their cost is low. Their advantage is that they absorb large particles (working as a pre-filter), thereby prolonging the performance of expensive VEPU filters.
Bactericidal air purifiers use ultraviolet radiation, which kills bacteria, viruses, mold, which fall under the action of ultraviolet radiation. Such ultraviolet radiation can work together with other air cleaners that use a fan. But there is no information about the studies that would demonstrate the effectiveness of bactericidal ultraviolet air purifiers in the fight against respiratory symptoms in people suffering from lung diseases. Nevertheless, for many decades, people have successfully used such air purifiers to reduce the risk of developing tuberculosis infection among staff and visitors to hospitals that treat these patients.
Ozone generators are devices that intentionally produce large amounts of ozone to clean a room. They are often used to clean rooms from smoke, which is a consequence of fire. Ozone causes bronchospasm in asthmatics, even at low concentrations, and, therefore, asthmatics should avoid it.
If you have asthma, an air purifier and room air conditioner may make breathing easier, but may not help. The same applies to hay fever (allergic rhinosinusitis) or COPD (emphysema or chronic bronchitis).
If you live with a smoker, then air purifiers can be extremely helpful. Passive smoking causes severe asthma symptoms. Passive smoking can also cause a “stuffy nose” in children. Almost all air purifiers perfectly remove the smoke from the room (if only the filter is big enough and the fan is turned on).