Smart Air Purifier

The article presents the concept and implemented, functional physical model of a mobile air
purifier for small public spaces or apartments. The purifier is a compact, controlled by microcontroller of
the Arduino UNO series. The model is equipped with a set of sensors allowing to determine the content of
PM 2.5 contaminants. After exceeding the adopted threshold in the software, the system automatically starts
the process of air filtering. The following factors are measured: solid contamination content, humidity and
air temperature as well as pressure drop on built-in filters. The purifier absorbs solid pollutants and reduces
VOC pollutants. The system has been equipped with a screen informing the user about air parameters and
the state of the filter contamination.
Concept of mobile air purifier
The project assumes the development of a system that supplies air to the room from the outside with unknown
pollination. The process of air quality improvement will be based on reactive air purification by the device in case
of detecting an abnormal concentration of one of the detected contaminants.
The design assumes that the filter will be mobile, with the capacity to improve the state of air in rooms with a
volume of about 130 m3 (approx. 50 m2 ). It was assumed that: the sensory system should monitor air dustiness,
temperature, humidity and pressure drop across the device's filters; the device switch on automatically,
information about air condition, temperature and humidity should be provided to the user via LCD
display, the filtering system should trap particles PM 2.5 with the efficiency of min. 95% and the used fan should
provide air flow of min. 100 m3/h, due to economic aspects, it was assumed that the accuracy of the used
sensor will only allow approximate measurements, therefore it will be necessary to use an additional button
activating the filtering system regardless of the sensor's indications, the filtering system should be monitored, i.e.
the user should be informed about the necessity of replacing of the filter cartridges, e.g. with an appropriate
message on the display, unit cost of the device should not exceed 250 €.
Originally, it was assumed that the system's operation algorithm should take into account the signals from
measurement transducers detecting the concentration of PM 2.5 dusts, formaldehyde, oxide and carbon dioxide.
Lack of coupling with the ventilation system means that the system will not be able to reduce CO and CO2
concentrations. For economic reasons, CO, CO2 and formaldehyde sensors have been abandoned. It was
assumed that the cleaning system should be equipped