Home & KitchenAir Purifier

What Should I Look for in an Air Purifier Before Buying it?

Air purifiers can be quite effective in improving the quality of your indoor air. Though they may have limitations when it comes to certain pollutants such as nicotine, it is still quite effective in cleaning a myriad of air contaminants in your homes.

But to make sure that your air purifier is indeed working for you, you have to buy the right one. 

And here are several factors that will help you make a suitable purchase for your needs.

How to Buy the Suitable Air Purifier

Whether you need one for your bedroom or kitchen, these factors can help you decide the right model and size of air cleaner.

The size of the room and CADR

Air cleaners are based on the square footage of a room.

A small device is not suitable for cleaning a larger area, the same rings true with air cleaners and purifiers. So using small air cleaners for a big room will be useless. It will not have enough prowess to eliminate contaminants from the air. 


On the other hand, if you use a big air purifier for smaller spaces, it can be an overkill and will just be a waste of money.

Air purifiers will have this specification labeled properly. You’d easily know how many floor areas a specific air cleaner can cover. 

Determining where you want to place the air purifier can also help you pick the right size. 

Another more scientific approach to help you figure out what size of air purifier to buy is by knowing the CADR.

Most brands of air purifiers come with a CADR number. This is a metric measurement that helps us know how effective an air purifier is at cleaning various particles in a particular room size. The higher the CADR number, the faster it can clean out air particles.   Air purifiers with higher CADR ratings will be more beneficial in larger and more spacious rooms. 

There is also a simple way of computing the CADR

You need an air purifier with a CADR number that should cover at least two-thirds of your room. But keep in mind that it’s better to get one that has a higher CADR than the needed CADR for your room. 

Type and number of filters

It’s essential to know what type of pollutants are present in your indoor space. This will help you to pick the right type of air purifier, you’d have to check out for the filters.

Not all air cleaners are made the same. Some are equipped with filters for a specific air pollutant or contaminant. 

Also, keep in mind that the gold standard for choosing air purifiers are HEPA filters. In addition to this, enumerate the concentration of specific contaminants that you need to eliminate from your indoor space.

For instance, if you have pets, you should get an air purifier with filters that can effectively remove pet dander from the air. 


The number of filters also matters a lot. For starters, most air purifiers have at least two filters. The first one catches the larger particles and the second or main filter traps the smaller air contaminants. 

Some air purifiers are designed with multiple filters. This with additional filters will have more prowess that can trap more VOCs and bad odors. 

The air changes per hour or ACH

This refers to the number of times that all the air in your room will be cycled through your air purifier within an hour. Often, you can see this in the product description, so it pays to read the fine print.

You can also manually calculate this by measuring the volume of the room vs the capacity of the device. 

Efficient air filters should have at least two air changes per hour. But if you have more pollutants in the air, you should get one that has a higher number, especially if you also want to lessen the load of tobacco smoke if you have a higher concentration of bacteria or viruses in your homes.

An air purifier with an ACH rating of 4-6 is king when it comes to this specific need. 

Other features

There are added features that can add value to your air cleaners.

For instance, photocatalysis uses light to remove bacteria and pollutants from the air even in water. It can target gas pollutants and more VOCs that other air purifiers cannot eliminate.

Some are equipped with UV height and ionizers that can enhance the filtration process. But one thing to keep in mind is that it can also be a bit irritating to those with lung issues so you have to weigh the cons vs the pros. 

There is also  UV sterilization. This is often used in hospital settings and is very efficient in resisting pathogens and preventing their spread. This is very effective in killing bacteria since it does not lead to bacterial resistance. It is best paired with HEPA filters. 

Level of noise

Check for the technical specifications of the unit and decide where you want to place them in your house.  An air purifier in the bedroom must operate quietly so your sleep will not be disturbed.

Some units can be quite meek while others can make a noticeable noise while in operation.  

Cost of Maintenance

There are two cost components in owning an air purifier. The upright fee and the cost of maintenance.

Filters are replaceable and you need to buy a new one when it becomes saturated, otherwise, it will not be efficient in cleaning anymore. 

Some filters are cheaper, but they often need to be replaced more often than more expensive filters. 

So you have to consider this continuing cost if you decide to buy air filters.  

Energy efficiency

As with any electrical appliance, air purifiers can either be cost-efficient or a liability to your electrical cost.

This will depend on the model, the size of the unit, and the surface area of the room. Bigger air purifiers often consume more power. That’s why using a huge unit for a small room can just be a waste of money.

Buying the right one will help you save money


Even indoors, you are not spared from air pollution. A lot of household appliances are giving off loads of harmful chemicals and air contaminants.

So COVID or no COVID, air purifiers are essential in every home. It can keep indoor air clean, and free of pollution, improve the quality of your life. But you have to pick the right type of air purifier to enjoy this. 

Buy the wrong one and it will not be able to efficiently clean your indoor air, thus will be a waste of money.

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