Abstract: An air conditioner with coolant pumped from a chiller first through a heat exchange conduit of an outside air heat exchanger to provide a minimum wetted surface temperature when treating undiluted outside air at its current temperature and humidity as it passes through this heat exchanger so to make maximum use of the available potential difference between the outside air and the coolant and therefore to cause maximum dehumidification. The leaving coolant from the outside air heat exchanger is the source of the coolant which then passes to the return air heat exchanger which cools and dehumidifies the return air. The leaving air streams from the return and outside air heat exchangers are mixed to become the supply air for a conditioned room which is economically dehumidified without need to overcool and reheat, nor to curtail the design flow rate of ventilation air and hence without contributing to conditions which are associated with the "sick building syndrome.

Abstract: A fluid mixing device has a chamber with a fluid inlet and an opposite fluid outlet. The device causes a flow of a first fluid wholly occupying the inlet to separate from the chamber wall upstream of the outlet. The distance between the flow separation and the outlet is sufficiently long in relation to the width of the chamber for the separated flow to reattach itself asymmetrically to the chamber wall upstream of the outlet and to exit the chamber through the outlet asymmetrically. A reverse flow of the first fluid at the reattachment and/or a flow of a second fluid induced through the outlet thereby swirls in the chamber between the flow separation and the reattachment and induces precession of the separated/reattached flow. This precession enhances mixing of the flow with the second fluid from the exterior of the chamber.

Abstract: An air conditioned space is cooled within a narrow target zone (as depicted on a psychrometric type chart) within which human occupants of the conditioned space would feel thermally comfortable, wherein factors including the heat transfer resistance of occupants' clothing and level of physical activity determine the target zone, by a method which includes correction of operative temperature, relative air velocity and humidity within the conditioned space, inherently controlling humidity by control of effective dehumidifier size while maintaining a low face velocity of air and a high velocity of coolant flow, but varying either, or both, dehumidifier size and the leaving air temperature if humidity ratio falls below four or exceeds thirteen grams of water per kilogram of dry air.

Abstract: An air conditioner dehumidifier comprising coil portions cooled by a fluid coolant such as by chilled water or refrigerant. As the required air sensible and latent cooling demands and their ratio varies in the conditioned space, the number of operational coil portions and the velocity of the coolant flow through each is controlled, by valves or other means, increasing coolant velocity while reducing the number of operational coil portions and vice-versa, to provide the coil surface area and the coil surface temperature necessary to cause the required degree of dehumidification and the required degree of sensible cooling in the required ratio to maintain comfortable conditions in the conditioned space with low energy consumption at all cooling demands.

Abstract: An air conditioner dehumidifier comprising coil portions cooled for example by chilled water or refrigerant. Under part load conditions, restriction of coolant flow below peak load flow, or its total elimination, is limited to some only of the coil portions, while the remainder may receive as much or more coolant flow as at peak load conditions. The relatively unrestricted coolant flow through this remainder can be greater than that under peak load conditions due to more pump output being available to supply the reduced active size of the coil.