Philips Series 3000 AC3821 Air Purifier Review: Exactly right

March 31, 2022 0 Comments

Detailed Review of Philips Series 3000 AC3821 Air Purifier

Philips has a range of air purifiers that it offers in different price segments. We have the Philips Series 3000 AC3821 / 20 Air Purifier for review which features a price tag of Rs 37,995 on the official site of the company but retails on Amazon for around Rs 22,999. We tested the device during the Diwali season, when air quality was extremely degraded and continued long-term testing in the summer. Will the air purifier be able to fight the highly toxic air or will it give up in this difficult situation? We’ll find out.

Construction and design

We rarely see an air purifier designed for an Indian home without a solid build and functional design. The Philips AC3821 / 20 is no exception. It sports a rugged build with an aesthetically pleasing design, although it bears a resemblance to most box-type air purifiers. It plays in rounded corners and is equipped with wheels that help it rotate effortlessly. The device sucks air from the back through horizontally moving slits and has a latch to its right, which is actually a panel that needs to use a humidity feature to fill the water.

Philips AC3821 / 20 expels fresh air from above. One of the top panels has touch-based controls for running the air purifier and the front has a small display. This display shows various metrics related to indoor air quality, such as current PM2.5 levels, which it measures with the sensors on the left. The display allows users to understand the condition in which the air purifier is operating if the humidity feature is enabled, or if the filter needs to be replaced.


The Philips AC3821 / 20 Air Purifier is equipped with three separate filters that enable it to remove particles and gases. It plays a pre-filter, followed by an activated carbon filter and a ‘nano protect’ filter, a term used by Philips to describe a HEPA filter that traps PM2.5 and small particles. The pre-filter works by capturing large particles, mostly PM10 and large particles. Hair strands, pet dandruff and large dust particles fall under this category. We noticed that after using the air purifier for several weeks, the pre-filter accumulated a lot of dust, which indicates that it is working quite well. Similarly, the HEPA filter has turned gray due to accumulation of trapped particles.

This is followed by activated carbon and a ‘nano protect’ HEPA filter that works to get rid of small particles and air from the lens. The carbon filter has a hive structure and contains activated carbon, which absorbs harmful gases such as benzene and formaldehyde, which are usually produced indoors during the cooking process. In the case of HEPA filters, the pleated design enables it to hold particles up to 0.3µm in size. After all, both filters are said to last approximately 24 months, but this may vary depending on the region of contamination where an air purifier is used.


Most air purifiers follow the same general rules of sucking air from an inlet, filtering it in the process, and releasing fresh air from an outlet vent. The effectiveness of an air purifier depends on many other factors such as how well it is able to conduct air in a room if there are gaps or leaks in which non-filtered air flows around the filters. How strong the filters are in trapping harmful particles in the air also affects the ability of the air purifier to clean the air.

We tested the Philips AC3821 / 20 Air Purifier in such a way that it gives an accurate idea of ​​how well it performs. Our standard test combines the operation of an air purifier in three different locations with different air quality levels. Room 1 is an area where air quality has deteriorated considerably as it is located in Delhi where the level of external air pollution is quite high. This room has an area of ​​120 square feet and a ceiling height of 12 feet. On the other hand, the level of air quality in Room 2 is between low and medium. Its ceiling height and area are 12 feet and 140 square feet, respectively. Finally, Room 3 is located in a relatively clean area where the amount of airborne particles is low. It has a ceiling height of 12 feet and an area of ​​350 square feet. In addition, the Philips Air Purifier displays current PM2.5 levels but we used our own air quality monitor to see how well the device performed. Note that we have recorded PM2.5, PM10 contaminant concentrations and not weights, and these are mentioned in µg / m3.

In room 1, the levels of PM2.5 and PM10 were 92 and 112 µg / m3, respectively, before our standard 45-minute test began. Note that the National Ambient Air Quality Standard sets the approved PM2.5 and PM 10 levels at 60 µg / m3 and 100 µg / m3 (over 24 hours). A healthy person, when exposed to contaminants above the above levels, can develop health complications over time. Living in an area with high levels of pollution can cause a person to be allergic to high levels of air pollution or even at high risk of developing lung and / or coronary complications.

Back in the test, we let the air purifier run at its maximum speed for 45 minutes. We noticed that after testing, it dropped to PM2.5 level 24 and PM10 level 21. The overall AQI (calculated based on PM2.5 particles) has been lowered from 169 to 76, which is moderate in AQI. Although the indicator is not excellent, the air purifier has performed well enough to make the air better.

In room 2, the air purifier started trying to filter the PM2.5 and PM10 levels, which stood at 50 and 58, respectively. Although the level of contamination was not really very high, an air purifier is still tested in this situation because it is already difficult to reduce the level of contamination. After our standard 45 minute runtime, both PM2.5 and PM10 levels dropped to 10 and AQI improved from 136 to 42.

In this case, Philips AC3821 / 20 has done a good job and is the best in terms of efficiency.

Coming to Room 3, which is a conference room in our office, PM2.5 level was 72 and PM10 at 83 had an AQI of 159. After 45 minutes, PM2.5 and PM10 dropped to level 25. And 32, respectively, while AQI has improved to 78.


Although the primary function of an air purifier is to capture harmful particles in the air, many companies combine additional features to make the device an attractive purchase for customers. Philips Series 3000 AC3821 / 20 air purifiers are equipped with a humidity feature that enables them to increase humidity in their room while purifying the air. Moisture comes in handy in the winter season and helps to alleviate problems like dry skin or sore throat, chapped lips. Humidity is also beneficial when someone is suffering from flu or cold, but keep in mind that excess moisture can cause some air problems.

Although the Philips AC3821 / 20 air purifier comes equipped with a humidifier, the company already offers standalone devices for humidity. All of the company’s products, including tested purifiers, have NanoCloud technology This technology enables the company’s device to humidify the air using small water molecules that are proven to reduce the amount of bacteria in the air and do not cause white spots or wet floors, which is a common problem when using an air humidifier.

The most common problem when using a humidifier is that a fine mist is released into the air, settles around your home and evaporates leaving white spots. This is a common occurrence that can be avoided by using filtered water in the moisture process. Phillips advises people not to use tap water for moisture. We noticed that the moisture process in Philips Air Purifier works well and, as advertised, does not cause white spots.

It should be remembered that a humidity setting is being used. Crank it up to the maximum and the room where the humidity is happening will be warm enough even in winter. This is not actually caused by the device, but the air retains heat when the humidity level is high. Overall, the Philips AC3821 / 20 air purifier has strong humidity which makes it a good product for your home when combined with good air purification.


Most devices, including the Internet of Things (IoT) capabilities, are becoming smarter these days. However, Philips has chosen to go traditional with its AC3821 / 20 Air Purifier because it does not have IoT support or app compatibility. The touch-controls of the device are placed next to the air outlet vent at its upper end. Includes a standard on / off switch, a child lock that deactivates all other buttons, air purifier speed control, slip timer, automatic mode, a switch to dim the display, a humidity level to set and a mode to change its operation mode. .

Most controls are self-explanatory. However, in automatic mode, the device detects the amount of air pollution and dynamically changes speed to purify the air. Additionally, the device has three automatic modes that it manages. The first is a normal mode, the second is an over-sensitive allergen mode and the third is sleep mode. To select the humidity level, the device offers four pre-set levels between 40, 50 and 60 percent for selection.

The last row

The Philips AC3821 / 20 is a good air purifier that works well in reducing harmful particles from the air. However, it falls short in the features it offers compared to its competitors. In this price range, or even less, you can find devices that offer more functionality, including similar air purifiers. The plus point of Philips Air Purifier is that it provides strong humidity which can come in handy, but only in certain months. While the Air Purifier works well, we think there are better options available like the Blueair Classic 280i, which is equally powerful for air purification and offers IoT features. In most cases the trade-off will be a humidifier available with Philips Air Purifier.

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