Abstract: A roof top cooler (10) is provided with perforate side walls (11), a top panel or lid (12), and a bottom panel which comprises a sump (13), and the sump (13) has four upstanding bosses (15) adjacent the four comers of the cooler (10). Hollow spacer posts (18) are carried by the bosses (15) and extend to the top panel (12), and telescopic legs (22) which are also of circular cross-sectional shape and form the inner component of a leg and post assembly, the telescopic legs (22) being slidably adjustable within the spacer posts (18) and retractable for packaging purposes, and the telescopic legs (22) terminating in their lower ends in respective feet (23) which are affixed to their lower ends by means of swivel means (24, 25).

Abstract: The invention provides a conversion means for converting a fixed type evaporative cooler (10) to a mobile type that includes a base with an opening (15), a sump (14) which can be of a size to suit one or more large coolers, means to accommodate a pump in the sump, wheels (24) firmly attached to the sump for support and mobility thereof, a filling station (22) for depositing water into the sump, and means to secure the sump to the base of a large cooler (12). The means to accommodate the pump includes a buoyant platform (16) thereby enabling the pump to remain in communication with fluid in the sump irrespective of the fluid level.

Abstract: A contra flow air to air heat exchanger, and an evaporative air conditioner employing such a heat exchanger, wherein the heat exchanger (10) utilises a series of stacked plates (24), each having curved deep groove corrugations which form channels (27) with an adjacent plate which are inclined at a small angle with the channels (28) of the first plate (24), each stack of plates (24) having two inlet ducts (14, 16) and two outlet ducts (18, 20) and (19, 21).

Abstract: To improve both heat transfer and evaporation in a heat exchanger (10, 25, 42) of an air cooler, there are provided a number of spaced narrow wet wicks (13) over which air flows transversely, and those wicks (13) are sandwiched between impervious spacer sheets (11, 12), the surface configuration of the spacer sheets (11, 12) being non-planar so as to increase the areas of the wicks (13) over which air flows, and also to increase air turbulence and thereby mixing, the increased mixing not only assisting in the evaporation of water from wicks (13) but also assisting in the heat transfer through the spacer sheets (11, 12) which define the air passages containing the wicks (13).