Best Air Purifier for Every Classroom

You may have considered buying an air purifier (or it has even been recommended to you by healthcare personnel), an apparatus in appearance very similar to air conditioners but with the mission of returning better air than the one they trap. In this air purifier buying guide, you will find a simple explanation of how it works and how to choose an air purifier that meets your needs.

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How an Air Purifier Works

As a consequence, it returns cleaner air and in some cases, with fewer odors, since they trap the particles responsible for it.

To retain these particles, they first capture the ambient air using a fan and, after passing through a filtering system where the impurities are trapped, the air returns to the room anti-smoke.

Although there are several technologies to purify the air such as electrostatic precipitators or the use of ozone, as we have previously advanced, the one used at a commercial level is high-efficiency filters.

High-efficiency filters offer an effective and safe solution. Of course, they are not perfect, requiring the replacement of these periodically so that it continues to fulfill its mission. In fact, the starting point when choosing an air purifier will be precisely to know what degree of retention they offer.

Factors to Consider when Choosing an Air Purifier

The retention capacity of the filter that integrates the air purifier is essential because it determines the quality of the air that will come into the room. In this regard, the recommendation is to look for models that have HEPA filters (from the English High-Efficiency Particulate Air) and not “HEPA type”.

Why this nuance? For a filter to be called HEPA it must meet certain standards, that is, it must trap all particles equal to or greater than 0.3 microns in diameter with 99.97% effectiveness.

Thus, we can also find models with “HEPA type” filters, generally more affordable but also less efficient, which either do not meet HEPA standards or have not been tested in independent laboratories.

How big is the Room to Purify?

The next aspect to assess is to know the cubic meters of the room whose air we are going to purify. And, as with air conditioners, it is not the same to operate in a room of 10 square meters as to condition a room of 50 m ^ 3.

To size the room we will simply calculate its volume. This is its surface multiplied by its height. Air purifiers offer this data or an approximation to the surface to be purified in their specifications.

It is important to know this information to be able to size our purification needs so that we do not fall short or invest more than necessary in an oversized purifier.


Hand in hand with the purification needs is the power necessary to carry it out in the time specified in the specifications. In general, the more cubic meters we have to cover, the more power we will require. This power is usually given as a function of the flow of purified air per unit of time.

In case of not having enough power, the air purifier would be forced to operate for a longer time, something that in the long run would affect both the performance of the device, its useful life, and electricity consumption.


It’s easy to overlook the noise section when we’re choosing an air purifier, a mistake we’ll pay for as soon as we get it out of the box and up and running.

Although it is true that due to its dimensions it is a portable device, it must be taken into account that the air purifier will be operational in our home continuously, in our presence, and sometimes, when we are sleeping or doing activities that require silence.

In this sense, it is worth taking a look at the level of noise generated, always looking for those that are quieter or have a night mode. However, it is not the same to use it in the baby’s room to put it in an office.

To get an idea of ​​noise levels, a couple of notes: the ideal for sleeping is that it is less than 30 dB and the noise generated by a well-functioning refrigerator ranges between 30 and 50 dB.

Other Factors to Consider

After reviewing the fundamental factors, others may be interesting to us.

How they are managed and if they are programmable: While the most basic models are controlled on-site from the device itself, there are programmable and remote-controlled models or even an application to manage it electronically. Although they are not as popular as air conditioners or robot vacuum cleaners, there are already some models that can be integrated into the smart home, so that we can manage them using a voice assistant.

That includes sensors so that they work autonomously, detecting variations in air quality and particles, thus adjusting both their operating time and the power used.

That they have extra technologies that complement the purification of HEPA filters such as ionization, activated carbon, or ultraviolet light. Thus, those with an additional carbon filter are interesting if we seek to neutralize odors, ionizers help neutralize particles, and UV helps to neutralize bacteria accumulated on the filters.

The frequency of filter replacement: The useful life of a HEPA filter is limited and, although the manufacturer usually provides an approximate period of time to change it, some models report the deterioration of this key piece.

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