Car Air Purifiers

On 14 Jan 2015 I posted the results of my car air purifier tests here. The test compared the purification power of a car AC with that of a car air purifier.

Learnings: The purification power of a car AC is amazing. It takes you down to a PM concentration of under 25 µg/m³ (healthy) in five minutes. Whether the compressor is running or not, the car is running or not, the performance stays the same. Make sure your car is air tight, the vent is not exhausting air, and the fan is not on the lowest setting.

The filters in a car, like in a home air purifier, are passive. They are just pieces of carbon or paper. All they need to work, is a fan pushing air through them. The term car “AC” can be confusing. Both the air circulation in a car, and the compressor based cooling, are called “AC”. All we need for purification is the air circulation, which works in most cars even with the engine off. The compressor can be off.

The air conditioning control dials in a car’s control panel.

Let me illustrate that with this image above. In order for air purification to work in your can, the fan speed knob should be on 2 or more. The “inner circulation” button should be on – this ensures that outside air is not coming into the car. The A/C button can be on or off – this has no impact on the air purification process.

Test 1

Conclusions

• A car purifier, especially the no-brand kind that I tested, is entirely useless compared to the car’s built in air purifier.