Hey
@Wylie ******
! I'm the owner and electronics engineer behind AirDeveloppa :)
The reason why they unit does not have an embedded PM2.5 sensor it's a commercial one rather than an engineering one.
The purpose of our product is to offer affordable and effective air filtration to the masses. Our product achieves this quite well by removing all extra add ons and focusing on airflow, scientific testing and low power.
Also, adding a PM2.5 sensor will put me in direct competition with other companies and make the product more expensive to manufacture which it is not desirable.
We have released a new product, the AirCheck Business which helps local businesses in Chiang Mai to get more customers by showcasing their indoor air quality through our app. Kindly check the new AirDeveloppa app on the PlayStore :)
If you wanna come to my office and check note engineering stuff I'm happy to show you around