Most people consider spring to be the prime allergy season, and that’s true to a certain extent. However, the arrival of fall brings with it its own set of allergens. The resulting allergies can be exacerbated as people retreat indoors and breathe the same stale air, an effect that only gets compounded by the coronavirus pandemic.
What Causes Fall Allergies?
Allergies can be caused by many different factors. For autumn, the common causes are:
Ragweed pollination begins in late summer, continuing on up to October depending on the seasonal warmth. Even if the plant is not prevalent in your local area, the pollen can still be dispersed for hundreds of miles around through wind. People who are allergic to spring plants are also likely to be affected by ragweed.
Mold and mildew
The onset of cold and wet weather encourages mold formation. They can grow in moist places such as piles of wet leaves, gutters, and even damp areas around the house.
Humid places are prime breeding grounds for these microscopic parasites. They can proliferate in unmade beds, furnaces, and even air filters.
These are dead skin shed by pets around the house. Roughly 40% of people who suffer seasonal allergies also have pet allergies. Cats are twice as likely as dogs to cause allergic reactions, while among dogs Bulldogs and Saint Bernards rank the highest among allergy-causing breeds.
Other pet allergens include fur, saliva or urine.
How Air Cleaners Help
Air cleaners filter the majority of allergy-causing particles. These include pollen, mold spores, dust mites and dander. They also boost the air quality in enclosed environments, important as more people remain cooped up at home during the pandemic.
According to the Centers for Disease Control and Prevention, air cleaners “can help reduce airborne contaminants, including viruses, in a home or confined space.”
How to Choose the Best Air Cleaner for Fall Allergies
- Check the room size
Air cleaners come in a variety of sizes, from portable units to large free-standing boxes for whole house, industrial or commercial use.
Here’s a rough sizing guide to help you:
Air Cleaner Model
Small / portable units
Rooms or spaces up to 200 sq. ft.
Medium size units
Rooms between 200-400 sq. ft.
Large air cleaners
For rooms between 400-1,500 sq. ft.
For the typical home or commercial store
An air cleaner that is too small for a given space could be ineffective at filtering allergens and contaminants. It could also tax out the air filter faster, resulting in more frequent filter replacement.
An air cleaner that is too large for a room will purify the air faster, but at the cost of higher energy consumption. In addition, larger units tend to have more expensive filters and maintenance costs, so it makes sense to get just the right sized unit for the space.
- Look at the CFM
One important measurement of a unit’s air purification efficiency is CFM, or cubic feet per minute. This measures how many cubic feet of air per minute the cleaner can scrub. The higher the CFM rating, the larger the space it can clean.
A good rule of thumb is that you need 100 CFM for each 250 sq. ft. of space. A desktop air cleaner usually carries a rating of 100 CFM, while a standard room air cleaner has about 400 CFM.
To determine the CFM for your specific room, use the following formula:
CFM = Room size x Air changes / Hr
Room size: Length x width x height in feet
Air changes / hr: Refers to how many air cycles are required per hour. This varies depending on how the room is used:
For residential homes:
|Room||Air Cycles / Hr|
For non-residential spaces:
|Area||Air Cycles / Hr|
|Restaurant dining area||8-10|
|Food staging area||10-12|
|Theatre / auditorium||8-15|
- Look at the CADR
CADR stands for Clean Air Delivery Rate. This defines particles that can be filtered from the air times the CFM rate. CADR measures the efficiency of the air purifier in producing clean air for a given space.
According to the Association of Home Appliance Manufacturers, a good rule of thumb is to get an air cleaner with a CADR score that’s at least two-thirds the size of the space.
|Room size in sq. ft.||Recommended CADR|
- Determine what type of allergies you have
After choosing the right size, check what allergies you and your family members have. Then shop for models that filter those specific allergens. Most air purifiers filter smoke, dust, pollen, unpleasant smells, pet fur, and chemical disinfectants. But not all are rated for microscopic allergens.
- Check the filtration
Entry-level models usually have a single-stage filtration, meaning it uses just one filter. These are usually made of fine cloth to trap larger particles, and carbon to absorb odors. However, they are not as effective when it comes to smaller dust particles, pet dander, and mold spores.
More upscale versions have multi-layer filtration, where different filters are used to trap smaller contaminants.
Finally, top-end air cleaners use HEPA, or high-efficiency particulate air filters. HEPA filters can trap up to 99.97% of airborne particulate matter as small as 0.3 microns, which includes most allergens.
- Additional protection
Some air cleaners feature UV light protection. This uses short-wavelength ultraviolet light lamps to inactivate harmful pathogens and airborne microorganisms like bacteria, viruses and mold spores. It damages the DNA they need to live, rendering them harmless so they do not flourish in the air cleaner’s HEPA filter.
This technology creates negative ions using electricity, which then attaches to positively charged particles like dust, pollen and other contaminants. The resulting bond creates a dense particle that’s too heavy to free-float in the air and falls to the ground, where it can be swept up instead of circulating around the room.
Both UV light and air ionizing functions offer an added safety net that complement the filtration provided by the air cleaner.
- Noise level
Like fans, air filters have different speed settings. Budget cleaners usually have just 1 or 2 speeds (high and low), while more expensive units have variable speeds for high-efficiency or nighttime use.
Look for the decibel level on the label. Manufacturers are not required to state the sound level, so a unit without a dBA rating could mean it is loud, while quieter ones usually display the noise level up front. The typical air purifier emits about 36 dBA on low, while better models emit about 32 dBA on the same setting. For air purifiers for bedroom use, you will want to get the lowest possible noise level.
- Features list
You may also want to consider added features that make operation more convenient. These include:
- Remote control
- Smart home integration (via WiFi, bluetooth, or IR)
- App support (some units can be controlled via app and even tell you when it’s time to change the filter)
Total Home Supply offers a range of air cleaners that provide HEPA filtration, UV protection and ionizer function for unparalleled air purification in your home or commercial space. Check out our air cleaners page for more information.