Allergy season air quality kit
Updated
A particle monitor, a HEPA air cleaner sized by CADR, spare filters and a smart plug, plus a hygrometer and dust covers: a shopping list to cut airborne particles at home, with realistic yearly filter costs.
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Before you buy
An air cleaner is one layer. The EPA’s asthma-trigger guidance puts source control first: wash bedding weekly in hot water, use dust-proof covers on pillows and mattresses, vacuum carpets weekly, keep humidity between 30% and 50%, fix leaks, and keep pets out of bedrooms. Filtration removes some airborne particles. It does not clean surfaces, and it cannot promise relief from allergy symptoms. Talk to a doctor about symptoms.
Size the air cleaner by CADR
The EPA’s table of minimum CADR for 8 ft ceilings: 65 cfm for a 100 sq ft room, 130 for 200, 195 for 300, 260 for 400, 325 for 500 and 390 for 600. Its wildfire advice, a smoke CADR of at least two-thirds of floor area, produces similar numbers. The air purifier room size calculator adjusts for ceiling height. Choose one unit for the room where you sleep first. Keep its door closed.
What HEPA means
The EPA says a HEPA filter can theoretically remove at least 99.97% of dust, pollen, mold, bacteria and other airborne particles of 0.3 micrometers. Be careful with labels such as “HEPA-type,” which do not state that standard. Avoid devices that intentionally produce ozone: the EPA calls ozone a lung irritant.
Yearly cost of filters and power
- Filters. The EPA notes manufacturers typically recommend replacement every 60 to 90 days for filters in general; follow your model’s manual. Two sets at $20–$60 is $40–$120 a year; four sets is $80–$240.
- Electricity. A unit that draws 30 W around the clock uses about 263 kWh a year, roughly $47 at 18¢ per kWh (the EIA forecasts about 18.2¢ for 2026). Check your unit’s real draw with an energy-monitoring plug or our device energy cost calculator.
Humidity and the monitor
The EPA says to keep indoor humidity below 60%, ideally between 30% and 50%. See smart humidity control for dehumidifier and humidifier use, and our monitor guide for what PM2.5, CO2 and VOC readings mean. During smoke events, follow our wildfire smoke guide.
Where each item goes
| Item | Placement |
|---|---|
| Air cleaner | In the bedroom, with space around the air intake as the manual says, door closed |
| Monitor | At breathing height, away from vents, windows and the stove |
| Hygrometer | Basement, nursery or any room with condensation |
| Smart plug | On the wall outlet that powers the air cleaner |
Core items
Air quality monitor with PM2.5 and humidity
$50–$250Shows whether particle counts and humidity in the bedroom actually change after you start the air cleaner, and sends an alert when they climb.
What to look for: PM2.5 laser sensor, humidity and temperature, app history, optional NDIR CO2, local display, works with your phone ecosystem
See options on AmazonHEPA air cleaner sized by CADR
$100–$300The core of the kit: it filters the air in the room where you sleep. Size it with the EPA’s CADR guidance rather than a “covers up to” claim.
What to look for: true HEPA filter, smoke CADR from the table below, quiet low setting, filter-change indicator, no ozone generation, CARB certification
See options on AmazonReplacement filter sets × 2
$20–$60Buy the first year’s spare filters with the purifier, because a dirty, overloaded filter does not work well. Two sets cover a year on a typical schedule.
What to look for: exact filter model for your unit, HEPA plus carbon if your model uses both, sealed packaging
See options on AmazonSmart plug for the air cleaner schedule
$10–$25Starts the air cleaner before bedtime or when the monitor’s reading rises, without wiring anything.
What to look for: 15 A rating, local control or Matter support, scheduling, energy monitoring; works only if your purifier powers on by itself after a power cut
See options on AmazonNice to have
Digital hygrometer
$10–$40A second reading for rooms the monitor is not in, such as the basement or a nursery.
What to look for: humidity and temperature, min and max memory, stated accuracy
See options on AmazonDust-proof mattress and pillow covers
$20–$70The EPA lists dust-proof covers among the steps to reduce exposure to dust mites. They address the bed itself, which an air cleaner cannot do.
What to look for: zippered encasement that fits your mattress depth, breathable fabric, machine-washable
See options on AmazonVacuum with a HEPA filter
$100–$300The EPA recommends vacuuming carpets weekly with a HEPA-filter vacuum so dust is not blown back into the air.
What to look for: sealed system, HEPA filter, washable parts, a floor tool suited to your flooring
See options on AmazonMERV 13 HVAC filters
$30–$90Extends filtration to the whole house on a forced-air system, if the blower can handle it.
What to look for: the exact size of your slot, MERV 13, manufacturer note that your system supports it
See options on AmazonDehumidifier for a damp basement
$200–$400Keeps humidity from drifting above the EPA’s 60% limit, above which mold growth becomes more likely.
What to look for: ENERGY STAR certified, continuous drain, auto-restart, capacity for your space
See options on AmazonStep by step
- Measure the bedroom and find its CADR target with the calculator.
- Set up the air cleaner and the monitor. Give the monitor a day to settle and note a baseline.
- Plug the air cleaner into the smart plug and test that it resumes after you cut the power for a moment. If it stays off, set it to run manually and skip the plug.
- Create two automations: a bedtime schedule, and an alert when PM2.5 or humidity crosses your limit.
- Wash bedding in hot water weekly, install covers and vacuum with a HEPA vacuum.
- Write the filter change date on the air cleaner. Reorder before it is due.
Cheaper or upgraded versions
Budget version, about $110–$340: an air cleaner sized by CADR and a $10–$40 hygrometer. Run it by hand and change the filter on schedule.
Upgrade, about $500–$1,400: add a dehumidifier, a second air cleaner for the living room, an NDIR CO2 monitor and MERV 13 filters for the HVAC system.
Frequently asked questions
How big an air purifier do I need for allergy season?
Match the room. The EPA’s table gives 130 cfm for a 200 sq ft room and 195 cfm for 300 sq ft, assuming 8 ft ceilings. Choose a higher CADR for taller rooms.
How often should I change the filter?
Follow your model’s manual. The EPA says manufacturers typically recommend replacing filters every 60 to 90 days, and that a dirty filter will not work well.
Will an air purifier stop my allergies?
It can reduce some airborne particles, but it does not clean surfaces or replace source control such as washing bedding and controlling humidity. Talk to a doctor about symptoms.
Do I need a monitor as well?
Not required. A monitor shows whether particle counts and humidity change and can trigger the purifier. A budget version is a purifier and a hygrometer.