Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for monitoring air quality with multiple sensing devices. The methods, systems, and apparatus include actions of: obtaining first sensor data from a sensor that is not an air quality sensor, determining that the first sensor data satisfy a first air quality criterion, in response to determining that the first sensor data satisfy the first air quality criterion, obtaining second sensor data from an air quality sensor, determining that the second sensor data satisfy a second air quality criterion, and based on a determination that the second sensor data satisfy the second air quality criterion, activating an air quality device.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for monitoring air quality with multiple sensing devices. The methods, systems, and apparatus include actions of: obtaining first sensor data from a sensor that is not an air quality sensor, determining that the first sensor data satisfy a first air quality criterion, in response to determining that the first sensor data satisfy the first air quality criterion, obtaining second sensor data from an air quality sensor, determining that the second sensor data satisfy a second air quality criterion, and based on a determination that the second sensor data satisfy the second air quality criterion, activating an air quality device.

A smart artificial intelligence based mobile robot having an air purification, humidification, dehumidification, and ultraviolet cleaning-based system to remove pathogens is disclosed. The robot also acts as an emergency alert system for break-ins and human fall detection using AI algorithm. The mobile robot operates and navigates intelligently using real time data collected from the environment through various sensors and input devices. An object detection module may use inputs from the camera to recognize people, pets, and others by pre-trained machine learning data set. The mobile purification, humidity management and sanitizing robot includes a ball bearing for balance and a motor controller, which drives two motors and wheels. The central controller of the smart mobile robot system has memory and processor to handle navigation, communication, notifications, and air handling system through real time data collection.

--Building including a living space, separated from an outside space by an outer wall, wherein a heat exchanger unit is provided at the outer wall and wherein a ventilator is provided for forcing air through the heat exchanger unit, wherein an air outlet duct is connected to the heat exchanger unit for allowing air to be expelled from the living space through the heat exchanger, such that heat can be exchanged in the heat exchanger between air flowing into the living space and air being expelled from the living space, wherein in the living space at least one sensor unit is provided for assessment of air quality and/or noise in the living space and control of the ventilator and/or the heat exchanger unit based on the assessed air quality and/or noise level in the living space.