Abstract: A diffuser is provided with three discharges. Two of the discharges are directed in one direction and, when installed, would be directed towards the outside wall of the conditioned space. The other discharge is directed in the opposite direction and would discharge into the interior of the conditioned space. Responsive to the temperature of the conditioned air being supplied, either one of the two discharges in the one direction or the discharge in the opposite direction is blocked. This results in two discharges in one direction or one in each direction with the discharge area being the same in both instances.

Abstract: A control for a plurality of air conditioning units installed in separate rooms of a multi-room building, with each air conditioning unit having an on-off switch to selectively connect the air conditioning unit to a source of electrical power. The control includes a switch for simultaneously interrupting the electrical power supplied to each air conditioning unit to place each unit in an off state. Once the supply of electrical power to each unit is renewed, each unit is prevented from restarting until the unit's on-off switch has been manually moved from its on position to its off position.