How can a purifier ease asthma?

Asthma causes inflammation and narrowing of bronchial tubes which restricts air to and from the lungs. Exposure to smoke, dander, microbes and allergens can trigger and worsen the symptoms. Since air purifiers work by filtering the air of these airborne particles and cleansing it, it can prevent and alleviate hypersensitive reactions. Filters, such as the gold standard HEPA filter, clean the air of particles that are as small as 0.3 microns at an efficient rate of 99.97%. For perspective on the size of the particles, the width of a human hair strand is 100 microns.

Features to consider while choosing an air purifier for asthma

The following are the certain features which determine the quality and performance of air purifiers.

Filters types

The effectiveness of an air purifier mainly depends on the type and number of filters. Filters can be replaceable or permanent, like the IFD filter in Honeywell HFD-120-Q.

The best top rated air purifier for mold and asthma combines several filters to target various contaminants. A pre-filter captures large particles which can clog the other filters while the main filter traps the fine particles. An activated carbon filter absorbs pet odor, smoke and other gaseous pollutants while an ionizer discharges negatively charged ions into the atmosphere that attach themselves to 0.01-micron-sized airborne particles to remove them.

The HEPA (High Efficiency Particulate Air) filter is considered the standard worldwide because it can eliminate tiny 0.3-micron particles and cleanse the air of at least 99.97% of harmful microbes and allergens while a regular filter, such as the permanent IFD filter of Honeywell HFD-120-Q, has a maximum effectiveness of 99% and can only capture particles that are bigger than two microns.

For the best HEPA air purifier for asthma, consider Coway AP-1512HH or Oransi Finn OVHT9908 which both feature four stages of filtration with a pre-filter, an activated carbon filter, a HEPA filter, and a bipolar ionizer.

CADR level

Clean Air Delivery Rate is a standard testing system by the Association of Home Appliance Manufacturers (AHAM) which measures the effectiveness of a portable air purifier to remove tobacco smoke, dust and pollen pollutants from the air. The CADR rating indicates the volume of air filtered in cubic feet per minute, with a high rating indicating faster filtration and higher output of clean air.

Winix 5500-2 has a high CADR rating of 243 for dust, 246 for pollen, and 232 for smoke. This makes it one of the top contenders for the best air purifier for allergies and asthma.

Coverage area

Besides CADR rating, air purifiers are also rated according to the specific number of square feet they are designed to clean. This is referred to as the coverage area. Using a low coverage air purifier in a large room will reduce its effectiveness.

To identify the most suitable air cleaner based on coverage, measure your designated room including the height and select a model with a higher recommended coverage area than the size of the room. This allows you to operate it on lower speed efficiently and noiselessly while retaining a high output.

Noise level

The essence of an air purifier is for us to have clean, breathable air that can prevent and alleviate our respiratory problems, not add migraines to our symptoms with noise that can wake up the dead.

Air purifiers usually feature multiple fan speed settings with varying noise levels. To co-exist peacefully with them and even sleep soundly as they run, choose a model with adjustable speed so you can select the lower one which is quieter. GermGuardian AC5350W has five fan speed settings, including sleep mode. Its highest speed setting also produces minimal white noise.



Knowing the dimensions of an air purifier will help you calculate the available storage space, and make any needed adjustments to accommodate it. The size will also determine its portability, which makes it easier to move the unit from one room to another.

For instance, Oransi Finn OVHT9908 is seven inches long, ten inches wide and 22 inches long, with a slim tower shape for compact storage.


To know how long you should expect your air purifier to last, look at the length of its warranty as well as other incentives regarding labor, replacement of defective parts and after sale service. Honeywell HFD-120-Q and Oransi Finn OVHT9908 have long warranties of five years and ten years respectively.

Extra features

Extra features complement other functions by providing options for a more powerful performance, easy control, and greater efficiency.

This includes an automatic mode which chooses the best setting for the level of contamination, auto shut-off, ambient auto-dimming light, sleep mode for quiet operation, eco-mode for minimal energy consumption, air quality sensors and light which automatically detect the level of air pollution. Other handy options include adjustable fan speeds, filter change indicator which alerts you when replacement is due, scheduling timer for delayed start, and LED display panel for easy access of controls and display of feedback and other useful information.