Abstract: The present invention concerns a procedure and apparatus for controlling and maintaining air currents or equivalent in an air-conditioning installation or equivalent. The air-conditioning installation comprises one or several air-conditioning machines (P) for producing the desired flows, and one or several duct systems for conducting the flows into the desired room spaces (H.sub.1,H.sub.2 . . . ) or equivalent and/or out from the room spaces (H.sub.1,H.sub.2 . . . ) or equivalent. The duct systems consist of requisite trunk, zone and room duct systems (R,Z,C). In the procedure the air flow rates required at any given time in the air-conditioning system are determined on the basis of the air temperature and/or air quality and/or air noise levels and/or air pressure conditions and/or other similar factors. On the basis of the respective air flow rates determined by calculation, a combination of the set values for all control members (S.sub.1,S.sub.1.1,S.sub.1.2 . . .

Abstract: A method for regulation of ventilation, wherein air is removed out of a room space (H) or equivalent through an air-conditioning device (10) as outlet air (L.sub.1) and in which said air-conditioning apparatus (10) part of the outlet air is recirculated as return air (L.sub.2) back into the room space, whereby return air (L.sub.2) is mixed with outdoor air to be passed into the room space. Before the outlet air (L.sub.1) is made to flow via the return-air damper (15) to the point of mixing (C) of return air (L.sub.2) and outdoor air, the outlet air is fitted to flow first via the outlet-air damper (14) placed on the outlet-air duct (11a) and, thereupon, via the return-air damper (15). The portion (L.sub.3) of the outlet air (L.sub.1) that is not recirculated via the return-air damper (15) or equivalent is removed as waste air (L.sub.3), without throttling, out of the air-conditioning device. The invention also concerns an air-conditioning apparatus.

Abstract: The invention concerns a procedure for controlling volumetric flow rate in air-conditioning installations, wherein the volumetric flow passing through an air-conditioning duct is controlled with the aid of a control (10) disposed in the air duct by opening or closing the control damper (11) or equivalent of the control (10). In the procedure, the control signal of the control damper (11) or equivalent air flow-controlling member of the control (10) is non-linearized on the basis of the effective characteristic curve of the control and of the desired effective characteristic curve. The opening and closing of the control damper or equivalent of the control is controlled with the aid of said non-linearized control signal function. The invention also concerns apparatus for controlling air flow.

Abstract: The invention concerns a displacement ventilation control procedure in which the impurity and/or moisture concentration of the air containing impurities which accumulates in the part of the room or hall space above the staying zone and/or their changes and/or their differences are observed and the ventilation of the room or hall space is accordingly controlled. The invention also concerns a ventilation control unit.