Portable air purifiers can make a big difference in improving air quality around you, especially in shared public spaces. But with so many options available, how do you choose the right one? Here are the key factors to consider when selecting a portable air purifier that meets your needs.
1. Does It Use a HEPA Filter?
The first thing to look for is whether the air purifier uses a HEPA filter. A HEPA filter can remove at least 99.5% of particles as small as 0.3 microns. This includes dust, pollen, and even some bacteria and viruses.
If you’re concerned about odors, smoke, or chemicals (like those from cigarettes or pollution), consider a portable purifier with an activated carbon filter. Carbon filters are especially useful for absorbing gases and smells, making them a helpful addition if you’re in a smoky environment or near heavy traffic.
2. Check the Clean Air Filtration Efficiency in the Breathing Zone
For portable air purifiers, the primary goal is to ensure a high percentage of clean air in the breathing zone (30 cm), the area directly in front of the purifier where you sit and breathe. This is where clean air matters most.
To measure this, we use a particle counter to test the percentage of clean air at various distances from the purifier. For example, with the QT3 portable air purifier:
- At 30 cm, the QT3 provided 75% cleaner air. That’s an exposure reduction factor of 4 (calculated as 1 / (1 – 0.75) = 4).
- At an arm’s length (64 cm), the QT3 produced 40% cleaner air.
- Even at 1.2 meters away, the QT3 delivered 25-30% cleaner air.
Check whether the air purifier model provides these test results. The more clean air you can get in the breathing zone, the more effective the purifier is.
Read more: The Truth About Laminar Airflow in Air Purifiers: Myth or Reality?
3. Check the CADR
If specific breathing-zone data isn’t provided for the purifier, you can refer to its Clean Air Delivery Rate (CADR). CADR measures the total volume of clean air the purifier produces per minute.
While CADR is a good general indicator of a purifier’s performance, it doesn’t directly translate to how much clean air reaches the breathing zone. A high CADR doesn’t necessarily mean the air purifier will perform well close to you but it can give you more clean air overall.
The QT3 has a CADR of 37 m³/h and delivers 75% cleaner air at a distance of 30 cm. This performance can be a benchmark when evaluating air purifier models that lack specific filtration efficiency data. In comparison, most portable air purifiers typically fall within the range of 10–20 m³/h CADR.
4. Lightweight and Compact Design: Key for Portability
Portability often gets overlooked, but it’s important for a device you plan to carry to cafes, offices, or hospitals. A lightweight, compact air purifier makes it convenient to carry and use in various settings.
However, there’s a trade-off. Higher CADR often means larger and heavier devices because bigger filters, batteries, and motors are needed to increase airflow. At Smart Air, we recommend choosing a purifier that weighs under 1 kg for portability. Be sure to consider the weight and size when choosing a portable air purifier.
5. Battery Life and Charging Options
Check if the portable air purifier comes with a battery. If you’re using the purifier in places without easy access to power outlets, a battery is essential to have. Ideally, a portable purifier should have a battery life of at least 2 hours. Anything less can become inconvenient when you’re out and about for longer periods.
For example, the QT3 portable purifier has a travel version with a 4-hour battery life per charge. It also supports USB-C charging, and you can slot the battery into the device.
6. Know That More Expensive Doesn’t Mean Better
Don’t be fooled into thinking that higher price tags guarantee better performance. Air purifiers are relatively simple devices, just a fan and a filter. In fact, you can even DIY your own air purifier and bring it out with you for a fraction of the cost.
Many air purifier companies capitalize on the misconception that “more expensive” means “better,” charging more for what could be achieved at a much lower cost.
Smart Air’s QT3 is the most affordable portable purifier on the market for the amount of clean air it delivers.
Read more: How to DIY an air purifier?
Bottom Line: How to Choose a Portable Air Purifier?
When choosing a portable air purifier, focus on the features that truly matter.
1. HEPA filter and carbon filter
2. High filtration efficiency in the breathing zone
3. Clean Air Delivery Rate (CADR)
4. Lightweight design for portability
5. Long battery life and convenient charging options
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