Q&A: Can air purifiers get rid of household odors?

Our kitchen is poorly ventilated, so cooking odors tend to linger. Will an air purifier eliminate the smells?

Some manufacturers of air purifiers claim their machines will remove odors from your home as well as improve the overall air quality there. Hoping to sniff out the truth, we put five room air purifiers to the test.

Manufacturers use a range of different technologies to enable their machines to remove odors:
• The Whirlpool Whispure AP45030S, $230, highly rated in “Filtering the claims,” uses a thin carbon-fiber mat that also serves as a prefilter to remove large particles.

• The Bio-Net EGF Enhanced, a $750 electrostatic precipitator–type purifier, has a small shallow cartridge loaded with carbon granules.

• The IQAir HealthPro Plus, $800, and the Austin Air Systems HealthMate HM-400 (shown), $450, are equipped with large cartridges filled with carbon granules.

• The Winix PlasmaWave 5000, $300, combines a carbon filter with “PlasmaWave” technology said to, generate “both positive and negative ions” to create plasma clusters that “instantly neutralize viruses, bacteria, chemical vapors and odors in the air.”

Over the course of several days, we ran each of the five machines through its paces in the same sealed chamber we used to test for dust and smoke removal. Read the results of the testing below.

The first step involved filling the chamber with a cooking odor by heating ground cumin in an electric frying and pumping the aroma into the room via a duct. (There was no air purifier in the room at this point.) Every 15 minutes over the course of one hour, our trained panelists, seated at “sniffing stations,” took a test whiff of the chamber air to determine whether the cumin odor in the room was being reduced. The panelists determined that the odor stayed roughly the same during the one-hour test period.

To get the room ready for an air purifier, we ventilated it completely. Next, we placed an air purifier in the middle of the room and turned it on and then repeated the cumin test as described above. We followed the same procedure for each model.

Our findings: The Whirlpool, Bio-Net, and Winix air purifiers did not remove the odors and proved to be hardly an improvement over no air purifier at all. The IQAir and Austin Air models proved the most effective, though it took them an hour to eliminate the odor completely. Note that neither of these models was among the top performers in our tests for dust and smoke removal. Refer to our Ratings of room and whole-house air purifiers (available to subscribers) to find the top overall performers.

You’ll need to replace the odor filters on your purifier according to the manufacturer’s recommendation, typically every 3 to 12 months. The cost of replacement odor filters for the models tested range from about $8 for the Whirlpool carbon-fiber mat to about $100 for the IQAir large cartridge.

The bottom line? Instead of buying an air purifier to get rid of smells, you might do just as well by opening a window even for just a few minutes.—Ed Perratore

Essential information: Read “Tip of the day: How to choose an air purifier” for expert advice on choosing an air purifier.

Comments

[Mel]

I appreciate the scientific approach. I use a high quality air purifier in my home and it works wonderful on odors. It isn't one of the models that you mention testing in this posting though. It's especially nice to have since the outdoor air isn't always fresh. Thanks.

[Ben]

Most odors are molecular particles so a mechanical filter media like HEPA will not trap them. The IQ Air works using activated carbon and potassium permanganate. The model tested here has 6 pounds of this media, but other IQ Air models have 12 pounds or more of gas-control media.

Besides cooking odors, homes often have aldehydes (like formaldehyde), solvents, and ozone. None of these molecular contaminates can be effectively filtered with particle filters.

Controlling the source of the pollutants is the most effective, but even conscientious homeowners won't be able to eliminate all the sources. As long as there are common materials like MDF and particle board, there will be formaldehyde. Vinyl in one form or another is nearly ubiquitous, and so is dioxin.

Ventilation is an excellent option if it is done correctly. However, outside air has its own pollutants like dust, ozone, and sometimes smoke and carbon monoxide.

Opening a window can be a good or bad ventilation scheme. Besides often being wasteful of energy used to heat, cool, humidify or dehumidfy air, it can affect the house pressure balance -- especially if there is any wind. Pressure balance problems can suck radon gas out of the basement or crawlspace into the living space. It can also push moist air into building cavities where water condenses and mold forms.

Good ventilation is essential, but sometimes it takes knowledge of the building envelope, pressure differentials, temperature and humidity levels and the right method.

A gas-control filter is not a practical solution in and of itself, but it can be a useful component. The real drawback for them is that they cannot move enough air through the filter for a large area without a lot of noise. At low speeds (less noise) they only handle smaller rooms. Buying one for every room is costly, but consider that whole-house systems are also many thousands of dollars.

[Jerry]

I started looking for this Whirlpool’s Whispure AP45030S, at $230, and it is NOWHERE to be found for less than around $850 or more. What gives with that? Supply and Demand since Consumer Reports rated it best? It wouldn't have been rated best, if the price had been over $800. I'm not finding anywhere where you can buy one for $230, and i've found that true of alot of stuff lately on Consumer Reports. If anyone knows of a place, please let me know.

[nicole]

I agree with Jerry...as I could not find the top rated Whispure, I found that a comparable model could be up to $1300. I gave up and tried the 2nd rated air purifier which was nowhere to be found. I am now down the list to possibly the Hunter Permalife 30547 or the 3M FAp03-RS. If anyone has any comments on these, it would be appreciated.

[Dan]

I have a odor problem that I have not been able to find a solution for. There is a wine store next door and and the wine and fermentation odors somehow pass through the demising wall. We have sealed up the demising wall completely and we still get odors. (not on a consitent basis though) We are looking for a filer/air purification device that will remove the odors.

Will any of the tested devices work in my situation or is there another suggestion?

Thanx, Dan

[Brammy]

I am getting very disappointed in what I can find on CR. I subscribed to this in hopes of purchasing an Air Purifier among other products but this info seems so out of date. Where are the Rabbit Airs? The Sharp PlasmaCluster or any ofthe other mid-level purifiers (less than 800.00)? If the info that out of date. The Kensmore you mention is now the Envirosense I believe. Getting info on discontinued models really has not helped me.

As far as airing out a house, that can be easier said than done with a local failing grade in air quality and a cosntant pale of smoke hanging around, not to mention the high concnetrations of mold and pollen we have here in the deep south. I would really like a review on a more recently avail model of air purifer, something that is still on the shelves.

[Doug Atherton]

CR's article on air purifiers is seriously out of date. The Whirlpool Whispure 450 is no longer available at Amazon.com and no one else seems to have it. The Kenmore model is also not available at Sears. When is CR going to update its test information?

I'm considering Rabbit Air which is a popular model on Amazon.com. I need a unit large enough to clean a 2 bedroom apartment of cigarette smoke. Any ideas for me?

[Bronson]

I Agree with Dan, there are soooo many new air purifiers on the market that have better technology and better "everything".

I always tell my friends with smelly homes to first vacuum and dust the entire place, change their air filters and buy a dependable air purifier at www.trustedair.com. I disagree with this review. Do the sniff test again!