Equipment for cooling an air current comprises heat exchanger with sets of first and second channels, each defined by heat-exchanging walls so that heat between air currents flowing through channels is exchangeable

Humidifying devices apply moisture to the walls of the second channels and a housing accommodates the heat exchanger and the humidifying devices. The housing comprises an air inlet for introducing a primary air current in the first channels. A ramification splits the primary air current flowing out of the first channels into first and second part currents. The first part current is fed into the second channels. An outlet is provided for conducting the first part current flowing out of the second channels and the second part current. The primary air current is conducted through a part of the first channels, after which the direction of it is altered so that it is conducted through the other part of the first channels.