#TinhteTest: TCL FreshIN 3.0 - is drawing outside air into the room really effective?

After many testing projects and supporting Mr. cuhiep, today I officially have a test of my own air conditioner, the main character will be TCL FreshIN 3.0 with the highlight being the natural air supply part, from outside to inside the room.

After Mr. Hiep's series of articles about the TCL FreshIN 3.0 air conditioner, I saw a lot of questions about what happens if the natural gas is sucked in, but the natural gas is not ok? Does it make the air in the room better? So the purpose of this article and video is to answer the above question, is the natural air suction from outside brought into the room of the TCL FreshIN 3.0 air conditioner really effective?

General information

Before going deeper into the article, I will give a little information about the air conditioner I tested, this is TCL FreshIN 3.0, a special air conditioner with the ability to naturally draw outdoor air, filter it, then bring it into the room.

This air intake system is separate from the cooling system, with a separate air intake pipe, separate filter, and separate air supply door on the air conditioner. The process is as follows, first the air is sucked from a separate pipe, by a separate motor, with a maximum capacity of 3 cubic meters of air/hour.

Next, this amount of air passes through 4 filter layers including:

Finally, it is brought into the room through a separate air vent on the air conditioner. The purpose of this feature is to supply filtered natural outdoor air, continuously into the room, to improve the indoor air.

How I do it

I installed the machine in a room with dimensions of 410x380cm, height of 270cm with a volume of about 42m3, without affecting the air inside the room, leaving it normal, living normally with its use as a video studio. I set up an IQAir+ air meter to record the measured parameters. After the air in the room has stabilized and is as normal as the level Tinhte lives in that room, I start turning on the machine and set it to the fresh air supply mode with the highest capacity.

I installed the air conditioner normally, the air intake is located in the hallway outside the room, I haven't even bothered to change the filter since the admin tested it, just to test it for blood. AQI+ and average PM2.5 concentration on June 18, 2026, recorded.

As for CO2 concentration, I have the following practical experience:

Average AQI+ and PM2.5 parameters recorded on the AirVisual app on June 16, 2026, at the station "Ministry of Natural Resources and Environment Inter-Agency Area".

Parameters at the beginning, the machine has not been turned on yet.

Test 1

The first time, I tested on June 16, 2026, with the following parameters:

Parameters after 2 hours Results obtained:

From 2 hours onwards Summary of measurement results:

Average AQI+ and PM2.5 parameters recorded on the AirVisual app on June 18, 2026, at the station "Ministry of Natural Resources and Environment Inter-Agency Area".

Parameters at the beginning, the machine has not been turned on yet.

Test 2

The second time, I tested on June 18, 2026, with the following parameters:

Parameters after turning on the device for 2 hours Results obtained:

Parameters from the 2 hour mark onwards Summary of measurement results:

Read results and comments

After 2 tests, and the numbers I recorded of the timelapse process on video, you can see more, it can be said that after using this feature, the air in the room has improved. Luckily, my office is located in District 3, the atmosphere is quite good, average levels are recorded around 50-60, rarely rising. So the initial test level was around this level, 60 or especially the 2nd test, the initial number was only 17, because maybe before the 1st test, the air was already ok.

CO2 concentration during the 1 and 6 hour test.

Let's talk about CO2 concentration first

This is also the parameter that recorded the most improvement, it looked majestic from 2000 to around 1000... But actually it's quite normal guys, 2000 is because I stood in the room for a long time, because I had to set up, prepare, watch the lights... So it looks high, but I guess it will only be at 1300 to 1500. But that is more than enough, I feel okay with this result, because essentially TCL FreshIN 3.0 is only bringing natural outside air in, with a certain CO2 concentration (the number depends on the climate and locality), in my place, the outdoor level is usually 800, sometimes 900, sometimes 1000. But TCL FreshIN does not have the ability to filter out CO2 leaving behind O2, whoever said that is wrong. So when the machine has successfully brought the CO2 concentration level to the outside environment, that is the result I find ok. What is the purpose? When you stay in an air-conditioned, relatively closed room for a long time, the CO2 concentration will increase to 1300-1500. Although there is nothing dangerous, for some people with weak bodies, they will be able to feel it, creating a feeling of drowsiness and fatigue for unknown reasons. That's why the action is to step outside and breathe to stay awake. TCL FreshIN 3.0 continuously supplies air outside the environment, new air, CO2 equal to the environment into the room, thereby creating a positive pressure, which will push the old air containing more CO2 because we breathed before out, just like that we will always have better air to breathe, CO2 will not accumulate and gradually increase.

PM2.5 is different

PM2.5 is completely different from CO2, because TCL FreshIN 3.0 has up to 4 filter layers and has a HEPA layer that specializes in filtering PM2.5, air from outside, sucked in, through the filter layer, filtering out dust, dirt, hair, trash, especially filtering by PM2.5 => the decrease in PM2.5 concentration in the room is inevitable, I find this quite easy to understand. Similar to CO2, TCL FreshIN 3.0 continuously provides filtered air with less dust, less PM2.5 dust, thereby creating positive pressure, pushing air with PM2.5 in the room out, so gradually the PM2.5 concentration will decrease.

AQI+ and PM2.5 concentration in test 1, after 6 hours.

Talking about AQI+

As mentioned above, the improvement from 60 to below 10 is not too big, not as terrible as the smoke tests that cuhiep did. But for me, it represents the exact use case of a normal user, the air in the room is also at a normal level, with a blanket it's just a little worse. It shows the device's capabilities, true to normal use cases, effective, for me this result is ok.

But

The results were very positive, my husband and I quite liked this machine because of this feature. But again, what about other test conditions, what about areas with worse climate? I haven't really tested it yet, so I'm not sure, but in my experience, it will probably... need to change the filters faster, because the more dust there is, the more the filter has to filter.

Conclude

Basically, I believe you guys understand how it works and the natural air intake feature of TCL FreshIN 3.0 is effective. In conclusion, I just hope you guys understand, although TCL FreshIN 3.0 is not an air purifier, it is different in that it supplies new, filtered, better air into the room and pushes old air out, the air purifier is placed in the room to filter and re-filter the old air. I can't confirm whether this machine can replace an air purifier because there are many things to consider. But let's imagine, it is certain that the room must have air conditioning, and considering the fact that the air conditioner can both regulate the temperature and improve the air and the need to add an air purifier, we see that option 1 is more compact and saves more space. Hopefully after my test, you guys can understand a product line that is not new, but I think it's good but I haven't seen you accept it much. Thank you TCL for accompanying me in this article.