Do Air Purifiers Really Work?

It is a fact that we need good quality air in our homes and need to prevent outside air consistently entering the house. However, air inside the house is, in all probability, worse quality than outside. We have many air contaminants in our homes we do not think about such as mildew or mold. Additionally, there are various allergens present, as well as dander from pets, be they dogs or cats.

As a general rule, the air inside a home should, if anything, be much better than the outside air. However, many people suffer from asthma, sinuses, irritating cough, etc, and it is quite possible that the air in the home is polluted.

There is a solution to maintaining quality air inside the home: an air purifier. Air purifiers have become popular in the last decade and could be the solution to bad, stale air.

What can we expect to find in our homes? We have many airborne contaminants in the air, including dust particles, that have entered the house during the day and are securely trapped for a minimum of 12 hours, as the day wears on into the evening. Also, microorganisms including bacteria and VOC’s (Volatile Organic Compounds) can become trapped in a home. These contaminants can cause a multitude of allergies or trigger allergic reactions.

So, what can the average household do about this?

If you wish to improve your home environment, you can turn to appliances that filter and control the air. Now, we are told that there are devices that clean the air that you and your family breathe, but do they work as advertised? We can take a quick look!

Air Purifiers – do they do the job?

The short answer here is – Yes! All air purifiers are designed specifically to filter air entering your home by removing pollutants, and generally noxious waste products, but what do they take out and what is left behind? Manufacturers claim they are 99% efficient. This claim of 99% is achieved in a controlled environment. Depending on your environment this figure can change significantly. Let’s take a closer look at this, now. Although air purifiers certainly do work efficiently, the type of unit and in what circumstances it works, must be taken into account.

The Various types of air purifiers

The Active Type (electrostatic)

The active type remove impurities by electronic means. They use a combination of elements containing positive and negatively charges ions, which collect certain impurities. They do this by collecting particles onto electrostatic elements, attracting the dust to the charged surface.

Ionizer Filter

This is one of the most popular types of filters on the market. You may have seen them on a wall in a room, such as a medical suite waiting room, as one example. They emit electrically charged particles which “collide” with dust particles and drop them to the ground. This requires some additional work, as the floors need to be vacuumed on a more or less daily basis to completely rid the room of contaminants. Furthermore, particles may drop onto furniture, beds and couches, which will also require additional cleaning.

You can get the type of filter with a collecting plate, which is an oppositely charged direct current element. This will collect the particles. A simple cleaning is all that is necessary to “renew” the element. It should be noted that these units emit ozone that is unhealthy for people with allergies. Only units passed by The California Air Resources Board (CARB) should be used. These Ionizers are smaller units and can be wall-mounted but have a specific function. They are commonly sold as stand-alone units. They work similarly to some types of insect repellant units.

The Passive Type

Passive filters are the particle remover type and are the most common type. They draw air through a maze of filters one after the other. The elements, as they are called, are mostly renewable and need to be changed at some point after a period of use. The HEPA filter is an example of such a machine. It employs several different filters, some fiberglass, which traps dust or other contaminant particles. However, this filtration method will not catch all impurities. Gases, odors and VOC’s will pass through.

Activated Carbon Filter

Of course, we mustn’t forget the activated carbon filter, as it is particularly good at collecting VOC’s. They differ from the HEPA filters and they won’t catch everything. Gases, obnoxious odors and of course VOCs will generally slip past a HEPA filter. These activated carbon filters need to have their elements replaced on a more regular basis.
There are many new air purifiers on the market such as the virus treatment units which make use of far-UVC light sources. This UVC (Ultra Violet C) is a specific frequency of ultraviolet light that sanitizes the air by light. The specifics of which are extremely technical and we will not delve into that here.

All air purifiers draw air through the unit and into the room or space where they are needed. The unit consists of a fan that sucks in air and passing it over the filtration elements, whether active or passive. Many impurities such as pollens, allergens and even some viruses are collected in this manner. Viruses are limited to airborne viruses only. If you have allergies for example many air purifiers will help by reducing the pollen count and other factors. They will not eliminate impurities in a room that contains equipment or furniture that emits dust, for example. There are also air purifier units that have washable filters.

Where in our homes should air purifiers be placed?

With certainty, the bedrooms are an important place to put a purifier, as we spend a considerable amount of time there. Not to mention the amount of time you may be confined to the bedroom if you are sick or in poor health. Because of this, a purifier in the bedroom seems like a must. However, the question remains, are they?

Are air conditioners worth it?

Considering all we saw above, air purifiers really work and can make a difference to our health and livelihood, especially in bad conditions. Whether one needs an air purifier depends on quite a few scenarios. Cost is one condition, as air purifiers are fairly expensive, all things considered, with a starting price of $75 to well over $1,000, in some cases up to $3000.

There are running costs associated with these units as well. Some filters can be washed which is fairly easy and inexpensive, whilst others need to be renewed or replaced, which can be fairly pricey depending on the type.

To assess their cost versus having cleaner air, we need to look at the advantages and disadvantages of using air purifiers, taking into account the environment. Frankly, would they help?

The advantages

Purifiers provide a healthy environment. Our families are important and as parents, we want to keep our children from being exposed to dirty or contaminated air. Providing this is important in creating a safe home environment, especially for the children.

Some children are more sensitive towards allergens than others and have to endure conditions such as asthma or allergies. Having an air purifier for this reason alone, is a plus straight away. Babies, should also not be subjected to unclean air, again depending on the circumstances and location.

Purifying the air in proximity to beds, cots or other places used for sleeping, helps ensure babies and toddlers will breathe more easily. It may also lessen the chance of allergies being developed or triggered.

Pets in the house

Though we love all kinds of pets, our children come first. Our pets, also treasured, do unfortunately shed hair, fur and pose other general issues that create an environment that can pose a risk to a child’s health. In many cases this can cause unpleasant allergic reactions.

For these reasons, pet owners can benefit from having an air purifier. The HEPA filter will work best in such a case, as they capture dust and hair, and improve air conditions related to allergies to pets. The activated carbon filter, on the other hand works well with absorbing unpleasant odors, an issue often associated with owning pets. The choice on which filter to use, in the case of HEPA or activated carbon, becomes an important one.

Remove Kitchen and Other Unpleasant Environment Odors

If your environment happens to be a source of unpleasant odors, an air purifier will help. A good choice here would be a unit fitted with an activated carbon filter.

Should We Trap Allergens?

It is common knowledge the at least 30% of US adults suffer from one or another sort of allergy while the figure for children is around 40%. This is an incredible number and anyone spending extended amounts of time in the household or even rooms at school (in the case of children) should consider installing an air purifier of some type.

The HEPA filter with its multi-stages of filtration is highly effective in these cases, trapping pet dander, mites and most pollens. Of course, we cannot see these little irritations, anything smaller than 10 microns to be precise.

Remove smelly odours especially smoke

Smoke consists of airborne suspended particle matter and it is desirable to remove this from your house. If you have children it is even more imperative to remove smoke. An air purifier will remove smoke from the house and clean up the air we breathe.


Maintenance is required

Air purifiers, as we have said, work. However, to keep them doing their job as effectively as the manufacturers claim they need servicing. Remember they are equipped with filters and some of these need to be renewed. This can be an inconvenience as firstly these spares can be expensive and may not be readily available. Also, you have to purchase and install them or call your service technician to do so (even more expensive)> This is something to keep in mind when thinking of installing one. Remember your electricity bills will increase depending on how often the unit is running.

Performance issues

Although most manufacturers claim a 99% performance factor you cannot expect this, depending on your location and outside conditions. For example, using a purifier in a town where there are industrial operations emitting smoke will have worse performance due to the worse quality of air compared to that of a location on a hill far away from such factories. The 99% claimed is performed under strict environmental conditions and does not take location into account. Dust and embedded particles present in the house prior to the inclusion of an air purifier will not be clean it.

Noise Levels

There are very few devices that perform cleaning operations without producing some level of noise. Air purifiers fall into this category and some noise is to be expected. The flow of air and passing it through a filter system requires a fan and all fans emit noise of some kind. You need to assess this particularly if you have a relatively noise-free house. Noise can be irritating so an initial check for this should be done.

Will an air purifier really benefit me?

This depends on many issues the main one is taking into consideration the occupants of the premises. Does anyone suffer from any allergies? Are there asthma dwellers in the house? If the answer is yes, then possibly an air purifier can help with their quality of life.

Location issues are present, as well. If you live in a city with known bad air, then it will definitely add some benefit. If, however, you happen to live in the country where the air is relatively clean then you must question your decision to purchase one. Should none of the points be an issue in your house then it is possible an air purifier may not have any beneficial effect.

You can improve the air quality in your house by cleaning regularly, dusting, vacuuming with a good vacuum (maybe one using a HEPA filter) and airing the house out regularly. This, once again, depends on your location. Pets need cleaning and grooming and a pet grooming service may well eliminate any pet issues. The expense of an air purifier may not be warranted. People who are not familiar with the operation of an air purifier may be misled into thinking it is the answer to all issues, which it is not.

You will not need to clean your house as often with an air purifier

Wrong. This is a misconception. Air purifiers clean the air and not the surfaces of general household furniture such as tables etc. They can only remove dust that passes through them. Merely opening a door will allow dust to invade the house and it will not pass through the air purifier.

An air purifier will fix any allergy issues

Wrong again. An air purifier will certainly assist in reducing allergy issues due to air quality, but you cannot expect it to entirely clear up these issues. Many sales and marketing people have one thing in mind, to sell the product. They can mislead you into thinking that an air purifier is an answer to any problem such as allergies or people suffering from lung based issues. It will not, as we said earlier, but it will help. We spoke about mold and mildew earlier, however, many of these issues can be fixed by running a dehumidifier occasionally which obviates the need for purchasing an expensive air purifier.

We have previously mentioned that if consideration is given to the purchase of an air purifier it should be fitted with a HEPA filter. A HEPA filter can last for 12 to 18 months before the element has to be renewed to maintain industry standards.

Similarly, an activated carbon filter is simple but highly effective and will absorb most fumes and VOC’s. So, buying an air purifier with both of these elements, a HEPA filter and an activated carbon filter, has to be effective. This of course depends on why you will be using it.

Some features of air purifiers.


Auto mode enables a unit to monitor the quality of the air by using sensors that detect impurities passing across them. It is highly effective in the HEPA filter, as feedback is obtained from the activated carbon filter. This controls the speed of the fan and thereby contributes to saving electricity. They have a sleep mode on some models, which can either be controlled by light sensors or timing devices. Light sensors in a child’s room for example are useful as they lower the fan speed to eliminate noise. This is also useful should you forget to turn the unit off at night. You can override these features should you wish the unit to operate at full power all the time.


As previously mentioned, these units are not cheap, but add operational costs to the utility bill. Thought needs to be put into the purchase of these units, as a running cost is always present. There are some options for energy saving, though, as an added feature is incorporated into most units. There are fan speed controls that let you select the speed at which the air is drawn and blown into the room. This is also useful as the fans can be quite noisy, especially at night. You can also select the speed to suit especially if you are in the room. Some units are fitted with auto functions that power off, or reduce the speed of operation, depending on the air quality feedback from the elements.


Earlier we mentioned that ionizers do emit ozone and this may not be at a friendly frequency of operation. One should make sure that a purchased ionizer has been approved by CARB (Californian Air Resources Board). These can be harmful and are typically used in consulting room as bug eliminators. These emissions emit a frequency that collides with dust and other particles and drops them to the ground. These units are not recommended to anyone with allergies to these ozone emissions.


Homeowners do strive to make their homes as safe and as clean as possible especially if there are small children present. This is the main reason that they purchase these units. There is a consideration to be observed and that is to see if the quality of the air in relation to the outside air requires the use of an air purifier.


We have concluded that air purifiers are useful, especially if the inhabitants of the dwelling suffer from allergies. If this is the case, we can assure you that they do work and some thought is needed whether you really need one or not. A good tip is to check on your local AQI or air quality index which is usually a feature of weather stations. Pick one close by and check for yourself on this to see the quality of the air locally.

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