This article explains different types of air purifiers / air cleaners for asthma patients and guide to choose them.
Asthma and air purifiers
If you have asthma, then the air cleaner and room air conditioner can facilitate breathing, but may not help in this. The same applies to hay fever (allergic rhinosinusitis) or HNZL (emphysema or chronic bronchitis).
If you live with a smoker, then the air purifiers can be extremely useful. Passive smoking causes severe exacerbation of asthma symptoms. Passive smoking can also cause a “stuffy nose” in children. Almost all air cleaners perfectly remove smoke from the room (unless the filter is large enough and the fan is turned on).
Asthma and room air cleaners
Can air purifiers prevent the exacerbation of asthma symptoms?
Maybe. Room air cleaners remove the smallest particles that are in the air within the device. However, air cleaners are not able to remove particles of allergens caused by local sources of environmental pollution, for example, the products of the life of microscopic dust mites that swell over the pillow when you flop on it (or when you just turn and roll in bed). You inhale these allergens before they get into the air cleaner field. The air cleaner needs 10-15 minutes to clean the room from such temporary fires of dust and allergens.
Wall carpets – another powerful source of allergens, from which it is impossible to get rid of by one vacuum cleaner or air purifier. The accumulated allergens remain in the carpet until they are disturbed. When you vacuum the carpet, even using a good brush, a large amount of allergen is thrown into the room, even if a highly efficient vacuum cleaner is in operation at this time. Room air cleaners are also less effective if the source of allergens is in the house, for example, a cat, a dog, a bird or a hamster.
The action of the room air purifiers extends only to the room where they are located. Since about eight hours you spend in the bedroom, therefore, logically, this is the first place where an air cleaner should be installed. In addition, you spend a few hours a day in the kitchen and in the hall or study, so you will need a separate air purifier for each of these rooms.
Types of air purifiers
There are many different types of air purifiers, including the following:
The mechanical air purifiers use a fan that pumps air through a special screen that catches the smallest particles, for example, smoke, pollen, and other airborne allergens.
Highly efficient dust collector (VEPU) is one of the most famous air purifiers. WEPU (which means a type of filter, but not a brand name) was developed during World War II to prevent the spread of radioactive substances outside the laboratory. 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 necessary for the operation of the engine of the device. Noise can be reduced by using a large device designed for large rooms, and including it at a low speed. It is not recommended to direct the fan to carpets or curtains, as it can stir dust from carpets and curtains.
In addition, “Ultra-VEPU” is available, which capture very small particles of dust. Evidence that these devices are more effective in controlling asthma than with traditional VEPU are not.
In electric air purifiers an electric charge is used to attract and trap allergens and irritants. If the device consists of precipitating plate-like electrodes, the particles circulate inside the system; otherwise they stick to the surfaces of objects in the room and they must be removed mechanically (wipe with a damp cloth). The disadvantage of such devices is the formation of a small amount of ozone. Ozone irritates the respiratory tract, causing temporary bronchospasm in asthmatics and a “stuffy nose” in those with hay fever or rhinitis.
The hybrid air cleaner contains elements of mechanical and electric air cleaners.
The gas-phase (GF) air purifier uses activated carbon grain to remove odors (volatile organic compounds) and non-dispersible contaminants, for example, odors of cooking, smells of paints or building materials (eg formaldehyde) and perfume odors. These are black thin filter plates that are installed in front of the VEPU. The drawback of these filters is fragility, as 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 cleaners use ultraviolet radiation, which kills bacteria, viruses, mold, which fall under the influence of ultraviolet radiation. Such ultraviolet radiation can work together with other air cleaners in which a fan is used. 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 these air purifiers to reduce the risk of tuberculosis infection among staff and visitors in hospitals that treat such patients.
Ozone generators are devices that purposely produce a large amount of ozone to clean the room. They are often used to clean rooms from smoke, which is the result of fire. Ozone causes bronchospasm in asthmatics, even at low concentrations, and therefore asthmatics should be avoided.
An air cleaner for the whole house can be used if your house is heated or ventilated through air ducts. When using air purifiers for the entire house, the VEPU system must include filters designed to reduce dust and dirt in the ducts and coils of the system. These simple filters are inexpensive, but they need to be changed every one to two months. In addition, they retain only large particles, and not small, which most often fall into the lungs. You can buy more efficient filters (slightly more expensive), which catch smaller particles. They are often covered with electrostatic charge. Nevertheless, these filters quickly become dirty in dusty places, reducing the flow of air that passes through the system, thereby reducing the degree of heating or cooling the room.
You can add permanent air cleaners to the entire VEPU system for the whole house, but the devices themselves and their installation are quite expensive. Disadvantages of the system – the formation of ozone, a byproduct of electrostatic air cleaners; the need for regular cleaning of the coils; the need to maintain a constant fan operation (24 hours a day and 7 days a week) for air purification; high cost of electricity and strong noise from a large blower fan.
Choose an air purifier
Before you buy an air cleaner, ask yourself a few questions:
Is it large enough? Is it possible to handle this with a filter with cleaning the room, like my bedroom at a speed that is most comfortable for me? A suitable size of the device is determined by the intensity of the supply of clean air by the device.
How difficult is it to change (or clean) the filter? Ask the store to demonstrate this. How often should I change the filter (or two other filters) (when used in a house where a smoker lives, since this is the most difficult conditions for the filter to work)? How much does it cost to replace a filter? (Also check the cost of the filter by buying it online).
How much will the device cost for the year?
Does the device emit a lot of noise? This is a very important parameter for devices with a built-in fan. The indicators of the intensity of the supply of clean air – the figures obtained at the maximum speed of the device, at which the device produces maximum noise. Is it possible to sleep while the device is running? (Turn on the device and check, even if you are in a noisy store and it’s difficult to determine).
If you or a person close to you have asthma, and there is a smoker in the house, then the air cleaner will certainly help you to control the symptoms of asthma. If no one smokes in the house, the air purifiers may be useless. If, except for you, no one smokes, then the air cleaner will help everyone, except you. What is the conclusion about air purifiers and prevention of asthma symptoms? If you are a healthy person and live in a region with minimal air pollution, then perhaps there is no point in spending money on filters.