In our last post we discussed how air purifiers can help keep pesky mould spores from becoming a problem – and big patches or mould – and the different types available to homeowners. Today we are going to look at the individual specifics you should keep in mind while shopping to help ensure you spend your hard earned cash on the air purifier that is right for your unique home:
Air Purifiers and Room Size
The air purifier you should buy depends on the size of the room where you plan to use it. Make sure to check air purifiers for their recommended room size. It should be the same or greater than the room where you are going to run the purifier, but not too much greater.
The size of the room recommended for an air purifier is based on how fast the purifier can clean the air. For example, experts recommend that an air purifier should be able to clean all the air in a room at least twice per hour, and some recommend six air changes per hour (ACH). Generally, the more ACH the better.
Often an air purifier will have listed the volume of air cleaned at different fan speeds in cubic feet per hour, or cubic feet per minute.
Clean Air Delivery Rate (CADR)
Another measure of how quickly and how well an air purifier cleans the air is clean air delivery rate (CADR). CADR tells you the volume of air that an air purifier cleans of a certain particle per minute. It is found by multiplying the air flow in cubic feet per minute by the percentage of particles removed.
CADR rates for dust are between 10 and 400, for tobacco smoke are between 10 and 450, and for mould spores and pollen between 25 and 450. Consumer Reports rates CADR scores above 350 as excellent, and below 100 as poor.
Air Purifier Power Usage
Another consideration when buying an air purifier is how much electricity will it use. Usually the faster an air purifier can clean the air, the more power it will use. So purifiers for bigger rooms generally use more electricity. However, purifiers do vary in efficiency, with some being able to clean more air for the same amount of power.
Fortunately though, most air purifiers use very little power, often less than 10 watts on low, so you can run them continually without having to worry about the electricity bill skyrocketing.
Air Purifier Filter Replacement
The other operating cost, besides electricity, is filter replacement if you do opt for a model that makes use of them (as we explained in part one, not all of them do). This cost depends on how often you have to change the filter and how much a new one costs.
HEPA filter life can often range from about six months to five years. Sometimes they can be washed or cleaned and reused. When you are buying an air purifier, make sure to check how long the filter lasts and how much new filters cost.
Air Purifier Noise Levels
The final consideration is how noisy the air purifier is going to be once it is installed and running. Again, the noise level can be a trade-off for how quickly the purifier can clean air. The amount of noise the air purifier makes in decibels (dB) should be listed. Most air purifiers are very quiet though, often virtually silent on low speed and so should not be too much of a distraction.