Abstract: A humidifier has an improved bottle wherein a continuously open drain outlet is located at the lower extremity of the bottle, a drain pipe being connected to the drain outlet and extending up the side of the bottle such that the upper end of the drain pipe establishes the static water level in the humidifier chamber. Electrodes extend vertically within the chamber such that current passes between the electrodes, via water in the chamber, to heat the water. The impurity level of the water in the chamber is monitored and when the impurity level reaches a predetermined value the chamber is flushed by opening a water inlet valve for a period of time. An electrical contact is provided to detect a high water level and when the water level drops below the high water level such that the contact continuously senses the absence of water for a fixed period of time, the inlet valve is opened until the high water level contact once again senses the water.

Abstract: A zoned air conditioning system using a room air terminal which has the same horizontal dimensions as a floor tile of a raised tile floor such that the terminal may replace one tile in such a floor. The terminal includes a cool air inlet below the floor for drawing in cooling air circulated in the under floor space and a return air inlet in the top surface of the terminal. The cool air and return air is mixed in a mixing chamber and drawn from the mixing chamber by a fan and returned to the room through an outlet vent. The ratio of cool air to return air mixed in the mixing chamber is controlled by a modulating damper which is controlled in response to the temperature of the return air in order to control the room temperature in the region of the terminal in accordance with an adjustable set point. A heater is also provided in the terminal for those occasions where the return air is cooler than the set point.

Abstract: An improved air vent (10) comprises a frame mounted from folded sheet metal, incorporating air dampers (23,24) in the bottom thereof and a plurality of square grills (21) located on supports (18,20) at the upper extremities of the frame. The frame includes four walls (11,12,13 & 14) which form a housing, and this housing is divided by barriers (16,17) into a number of chambers through which air passes. Each chamber has a grill (21) covering its upper opening and a pair of dampers (23,24) which adjustably control air flow through the chamber. Each grill 21 has a plurality of angled louvres 22 which divert the air to one side as it passes through the grill and the direction (A) in which the air is diverted is altered by rotating the grill within the housing. In this way different grills within the assembly may divert air flow through each grille (21) is adjusted by its respective dampers (23,24).