It is a complex of weather conditions indoors: temperature , relative humidity , quantity of aero ions *, air exchange, air movement speed, content in air of firm particles (dust), existence of pleasant smells (aromatherapy), etc. Are considered optimum for a microclimate of inhabited and public places in a warm season: air temperature is 22-25 °C, relative humidity of 30-60%, air movement speed no more than 0,25 m/s; in a cold season these indicators make respectively 20-22 °C, 30-45% and 0,1-0,15 m/s. At the same time the difference of temperatures across from windows to an opposite wall should not exceed 2 °C, and down 1 °C on each meter of height of the room ^{[2] of [3]} .

For creation of a comfortable microclimate special systems are indoors used: in a cold season — systems of heating : gas, wood or coal furnaces; system centralized water, in rare instances (as outdate) steam heating (for residential and public buildings it is forbidden); heaters and electric heaters. Systems of a supply and exhaust ventilation (use of recovery of thermal energy of exhaust air is possible). Systems of moistening of air (steam, ultrasonic, with traditional evaporation (cold)).

In a warm and hot season — systems of ventilation and conditioning (coolers, dehumidifiers, obespylivatel).