The question then becomes what your air quality is like and what is the size of the space you’re trying to clean.
The manufacture does not always provide enough helpful information to help consumers determine how many air purifiers they will need. Sometimes all they provide is the room size the purifier is believed to clean on the box. Manuals, product specifications or descriptions may provide more.
So you may be left to guess a trial by error approach, until the problem is alleviated.
But there are a few simple guidelines that can help. We discuss those in the following paragraphs.
If the air quality of your house or apartment is really poor or a large area, then you may need a large capacity purifier or buy multiple units. Multi-level dwellings will need purifiers on multiple floors and possibly even more depending on area size. After pinpointing the source of the odor, place an air purifier paid link as close as possible or the center of the room but not too close to a wall.
Table of Contents
- Clean Air Delivery Rate CADR
- Air Purifiers CFM
- Noise Level
- Filtration Stages
- Air Quality Monitors
- Warning Signs
Clean Air Delivery Rate CADR
AHAM stands for the Association of Home Appliance Manufactures and is a body recognized by the EPA (environmental protection agency). It tests and rates air purifiers against manufactures claims to verify accuracy. Look for AHAM Verifide® of CADR and rating on device or packaging. You can perform a brand search to verify AHAM CADR certification for dust, tobacco smoke, pollen here: https://www.ahamdir.com/room-air-cleaners/
AHAM’s CADR ratings are for 3 types of contaminants smoke, pollen and dust. Each type receives a separate rating; maximum rating for smoke or pollen is 450 and 400 for dust.
Ratings for CADR are at the highest fan speeds.
AHAM recommends following the 2/3 rule when trying to find a unit with a good CADR (clean air delivery rate). For example, in a room size of 500 square feet you want a tobacco smoke rating of at least 333 CADR. The rule applies to rooms up to a height of 8 feet
The CDC (center for disease control) recommends at least 5 air changes per hour
If the manufacture gives you the CFM number then you can calculate the ACH (air changes per hour):
Step 1: CFM x 60 = Cubic Feet Per Hour
Step 2: Find cubic volume of room using: Length in feet x Width in feet x Height in feet
Step 3: Divide cubic feet per hour/cubic volume of room=ACH (air changes per hour)
Short version of formula ACH=cfm×60/Area×Height
Air Purifiers CFM
It refers to the air flow at cubic feet per minute. It was the standard measurement to determine air purifier efficiency. But that is no longer true and it has been replaced by the CADR rating. Some manufactures only provide the CFM rating and not the CADR.
As a general guideline when trying to get an idea of an purifier’s efficiency and the only information provided is CFM then again AHAM’S 2/3 rule would apply.
It’s not unusual to find local department stores and hardware shops only carry units capable of 1-3 air changes per hour. So shopping online and checking product specifications and certifications before you buy can be helpful and reduce the need to return an item due to insufficient capacity.
Noise Level
If you live in an area prone to wildfires, apartment tobacco smoke you may need to run it at a higher speed just to create fresh air. This is true more today than ever due to climate change. The pollution coming from these fires have creeped into our homes and made it difficult to breathe.
For those with lung diseases like asthma, bronchitis or COPD this is brutally true.
California and Texas have been especially hit hard in 2023.
Purifiers can be very noisy especially on high and the wrong one can make it hard to get a good nights’ sleep.
Chances are you will be running your it consistently. How much noise can you stand? A whisper is about 30dB, a ticking watch 20dB and 60dB(decibels) is about conversation level. Noise levels over 70dB over an extended period of time can start to damage hearing.
The good news is that many of the new air purifiers paid link have what is called a brushless motor that tends to be quieter and less of a distraction.
Filtration Stages
Today levels of filtration have greatly improve providing anywhere from 3-6 stages of filtration depending on the unit you purchase. Filter combinations of activated carbon, pre-filter, HEPA filter all working together help pull irritants out of the air and trap them to its’ surfaces.
Air Quality Monitors
Some purifiers come with an air quality monitor which change colors as the level of air contaminants increase. The fan speed will automatically increase to remove them and decrease once the threat is gone. These makes getting the right level of purification a set it and leave it operation; so even when you return home the air quality is good.
But even better are those with Wi-Fi capabilities. Just download the app to your phone view or control air quality and other features from anywhere, even when you’re away from home.
Warning Signs
A few warning signs that your being bamboozled or hoodwinked by the manufacture is when:
Some promise more than they can deliver and have no certifications. Often a clear warning sign can be when the number of watts for the motor is so small there is no way it can deliver on the promise of cleaning a large size room. For example, a claim to clean a room size of over a thousand feet but the motor capacity is just 18 watts.
Also take note that higher capacity air purifiers have larger filters or more filtering material allowing more pollutants to be trapped across their surface area.
And finally another red flag is if you can’t find any product certifications by a recognized testing authority. Reputable manufactures want to gain consumer confidence and will pay to have their products tested and verified for claims they make.