Abstract: A multi-functional room air conditioning unit that controls both heat and humidity as well as the concentration of airborne particulates. A control unit monitors temperature, humidity and air quality parameters and automatically programs the apparatus to take corrective action when one or more of the parameters is outside of the desired range.

Abstract: A portable air quality indication unit senses and indicates at least the ambient concentration of aerosols and particulates, the ambient concentration of a gas such as CO, the ambient temperature and the relative humidity, and displays the same. The gas concentration level and particulates concentration level are provided as good or satisfactory, bad or unsatisfactory, or fair/good, i.e., marginal depending on the relation of the detected level to the predetermined threshold level values of gas concentration, and particulates concentration. Temperature and relative humidity can be displayed on liquid crystal displays. A microprocessor circuit within the unit assumes a low-power standby mode, in which the gas and particulates sensor means are sampled at a relatively low rate, when the particulates level and gas concentration level are below their respective TLVs.