What is the Clean Air Delivery Rate (CADR)? The AHAM Label (found on the packaging of the air cleaner) lists three CADR numbers ─ one for tobacco smoke, one for pollen and one for dust. First, find the AHAM suggested room size noted prominently in the label. This suggested sizing should match the size of the room you are trying to clean. Next, compare CADR numbers from manufacturer to manufacturer and from air cleaner to air cleaner. Higher ratings for the dust, tobacco smoke and pollen CADR numbers indicate that the unit will filter the air faster than a unit with lower ratings. If the ratings are same from one unit to the other, then the air filtering performance is similar. Homedics AF-100 Hepa Air Cleaner Buy a Used "Homedics AF-100 Hepa Air Cleaner" and save 7% off the $129.99 list price. 18.1 x 20 x 8.8 inches #752,028 in Home and Kitchen (See Top 100 in Home and Kitchen) #480 in Home & Kitchen > Heating, Cooling & Air Quality > Air Purifiers > HEPA Air Purifiers

5 star60%4 star13%3 star10%2 star14%1 star3%See all 30 customer reviewsTop Customer ReviewsThe flaws kill it!!Very quiet and well designed.Smells like wet dogBurning or melting smellthis air cleaner is great. the filters are a little priceA-1Great FilterBreathe Easy: High-Performance Air Purifiers Most of today’s room air purifiers have higher air-cleaning ratings than ever before. However, questions exist about the ratings’ legitimacy and, thus, how effectively these models perform. When it comes to discussing the benefits of room air purifiers, manufacturers are pointing to higher test scores as a reason for consumers to be excited. You should temper any excitement, however, so you can understand what these scores mean and whether a high score is of any consequence to the room you that want to clean. Consumers who are in the market for an air purifier will find that prices for the majority of models increased by up to 10 percent over the past 3 years. “The raw materials in the construction of the units have gone up, such as copper and carbon,” says Michael Domon of Austin Air, which makes air purifiers.

He says his company’s models jumped in price by about $30 on average. crystal air leaf purifierHe says carbon, which is used in air-purifier filters, is becoming more expensive because of its use in a wider range of products.slant fin air purifier ionizer Association of Home Appliance Manufacturers (AHAM), which is a trade association, says room air purifiers are becoming more effective.nomorerack air purifier AHAM performs tests to determine whether the appliances live up to manufacturers’ claims, and it says more room air purifiers log higher scores for clean air delivery rate (CADR) than ever before. (CADR is AHAM’s measurement for the volume of filtered air that’s delivered into the room by an air purifier. The higher that the CADR score is, the faster that allergens, such as dust, pollen and tobacco smoke, will be filtered from the air.)

(Whole-house air purifiers are rated on their minimum efficiency reporting value, or MERV, by American Society of Heating, Refrigerating and Air Conditioning Engineers.) Wayne Morris, who is an AHAM technical expert, tells Consumers Digest that CADR scores rise every year. He says his association now sees more models that have a CADR score of as high as 450, which is the maximum score that AHAM’s test registers. Morris says that 3 years ago, only one model had a CADR score of 450. Today, at least seven do because of what he calls improvements in the air purifiers’ motor and the design of the fan blades to move the air throughout a room more efficiently. Click chart above to view full presentation The higher score also means a higher price for an air purifier. For example, the Blueair 603, which has a CADR score of 450, costs $800. The otherwise identical Blueair 503, which has a CADR score of 375, costs $700. According to our research, this is a representative increase between purifiers that have a CADR score of 450 and those that have a score that’s in the 300s.

However, an air purifier that has a higher CADR score isn’t necessarily the best choice for the room that you’re trying to clean. According to AHAM, a good rule of thumb is to look for an air purifier that has a CADR score that’s equivalent to two-thirds the size of your room’s area. For example, a 10-by-12-foot room—120 square feet—would call for an air purifier that has a CADR score of at least 80. (See “Calculating Your CADR Score.”) An air purifier that has a CADR score of 450, then, would be appropriate for a room that measures nearly 26 feet by 26 feet. Richard Shaughnessy, who is the director of indoor air quality at University of Tulsa, says AHAM’s rule of thumb includes caveats. He says CADR scores are based on the initial operation of the appliance. He says, on average, air purifiers can become up to 50 percent less efficient in only 6 months’ time. CADR scores also are based on an air purifier operating at its highest setting. Most consumers typically use the devices at lower settings to limit noise or the amount of air movement in a room, he says, which makes it proportionally less efficient.

For example, he says that if you operate an air purifier at half power, you should expect a CADR that’s reduced by roughly 50 percent from its advertised score. So if you plan to operate your air purifier at a lower setting, you might want to consider a score that’s higher than AHAM’s recommendation for the corresponding room size.Clean air is in short supply, thanks to all the unseen particulate matter floating around. According to data released recently by the Central Pollution Control Board, Delhi is in the “severe” pollution category, while Chandigarh has alarmingly high levels of particulate matter. The situation is pretty similar in many other parts of the country. Now that winter is setting in, cooler air closer to the ground level traps smoke and other particulates, worsening air quality. The smoke from Diwali firecrackers will remain suspended in the air longer; smog conditions in certain parts of north India are already making it difficult for people to breathe.

And, unfortunately, the situation isn’t much better indoors. But while you cannot really do much about the outdoor air, air purifiers can help improve the quality of air indoors to some extent. They cannot remove carbon monoxide or propane, but can filter out pollutants like particulate matter, aldehydes, chlorinated hydrocarbons, ethers, esters, ketones, halogens and sulphur dioxide. Why invest in an air purifier? If you keep the windows closed, particularly at night, the bedroom could have too much carbon dioxide a few hours after you’ve fallen asleep. If you open the windows, you are letting in the polluted outdoor air. An indoor air purifier can help trap allergens and viruses, allowing cleaner air to reach your lungs. We had tested some air purifiers in summer. New devices have come in since, tweaked for Indian conditions. There is greater emphasis on the thickness of each filter and fan speeds have been boosted for quicker clean air output. To make the buying decision easier, we have broken this down into the typical room sizes found in modern-day homes, and identified which purifiers work better in each.

The ideal air purifier for most study rooms should be powerful enough to clean room sizes up to 250 sq. ft (23.2 sq. m.). Known for its air conditioners and home appliances, Carrier Midea has also added air purifiers to the line-up. The MAPTT253EBN (Rs.12,999) has a three-filter set-up—pre-filter, HEPA (high-efficiency particulate arrestance) filter and activated carbon filter—as well as an ionizer to remove odour and pollen particles, and quickly cleans smaller-sized rooms. This has an extremely high maximum Clean Air Delivery Rate (CADR) of 270 cu. m. per hour (m3/h). Then there is Sharp’s FP-F30E-H (Rs.19,000), which comes with the Plasmacluster Ion technology—this replicates the positive and negative ions found in nature. These ions float around the room, attaching themselves to mould and viruses—they draw out the hydrogen on the bacteria surface, breaking down its proteins. This purifier has a more compact form factor. The design is such that it pulls in air through the back, which means you cannot place it against a wall.

The bedrooms in most modern-day apartments are usually 250-350 sq. ft, which is well within the range of most purifiers. The Eureka Forbes Aeroguard with Acton (Rs.12,990) is a powerful purifier, with a maximum CADR of 205 m3/h, and also includes a negative ion generator—negative ions are created in nature by water, air, sunlight and the earth’s inherent radiation, and clear the air of dust, mould spores, pollen, pet dander, odours and cigarette smoke. The Aeroguard with Acton improves the bedroom air quickly, and works well even if outdoor air is coming in. The niggle is that the unit works only with a wireless remote control, and there are no hardware keys on the device itself. Indian company Atlanta Healthcare has the Beta 350 (Rs.14,950), which surprised us with its tremendous attention to detail. Unlike Philips purifiers, which use the traditional air-conditioner air filter as the pre-filter, and Panasonic purifiers, which integrate the pre-filter in other filters, Atlanta Healthcare uses a very fine washable fabric pre-filter.

It captures dust, and that enhances the life of the next layer of filters in the purifier, particularly in our dusty environment. The Beta 350 is best at maintaining the room’s humidity levels because it has a glass fibre HEPA filter. This is good news for users who tend to suffer from a dry throat in winter. It has a fairly high 225 m3/h CADR too. Carrier Midea’s MAPFS331ECL (Rs.18,990) has a comparatively lower, 170 m3/h CADR, which means it takes a few minutes longer to clean the same room size than the Eureka Forbes Aeroguard with Acton. This, however, shouldn’t be a problem since these devices will ideally be running the entire day. The MAPFS331ECL is also the simplest to use and packs in all the features—ionizer, sleep timer, and a three-filter set-up. For bigger rooms upwards of 350 sq. ft, be they living, dining or home theatre spaces, the speed at which a purifier delivers clean air matters more. Which is why, the higher the CADR, the better. The Eureka Forbes Aeroguard with Acton Advance (Rs.21,990) can deliver a maximum 500 m3/h CADR.