Abstract: A hot water heater or similar heating device includes equipment for pre-cooling hot flue gas while preheating water for the water heater. It further includes a heat and mass exchanger for transferring heat and water from the pre-cooled flue gas to combustion air for the hot water heater. The pre-cooler may comprise a separate device or may be incorporated as part of a condensing water heater. The heat and mass exchanger may use membranes having condensing sides and evaporating sides, which allow water to pass from the condensing sides to the evaporating sides. It may further comprise troughs for wetting the membranes.

Abstract: The present invention relates to methods for indirect evaporative air-cooling with the use of plates, heat exchangers and feeder wicks—of the indirect evaporative type. Several components for an indirect evaporative heat exchanger described as follows: A plate for an indirect evaporative heat exchanger where the plate is made of laminate material having one sheet of wicking material for wet zone(s) and the other of a water proof plastic material for the dry zone(s). An evaporative heat exchanger is created by assembling the plates forming spacing for wet channels, (they are created by the wet zone of the plates,) and dry channels, (they are created by the dry zone of the plates,) with channel guides or corrugated plates. The spacing between the plates is defined to reduce pressure drop for increased airflow. A feeder wick system creates the wetting of the wet channels without excess water.

Abstract: Heat exchanger plates for indirect evaporative coolers, of the type having a dry side having low permeability to an evaporative liquid and formed to allow a product fluid to flow over a heat transfer area of its surface, a wet side designed to have its surface wet by an evaporative liquid, and formed to allow a working gas to flow over its surface to evaporate the evaporative liquid, further include edge extensions formed beyond the heat exchange area of the plates to facilitate removal of excess evaporative liquid. The edge extensions may slant or curve away from the wet side of the plates to assist in liquid removal. The plates may be used in a variety of configurations.

Abstract: A duplex exchanger includes first and second heat exchangers each including a main flow channel and a cooperating counterheat channel. The first counterheat channel is joined to the first main flow channel for receiving a cooled primary stream therefrom. The second counterheat channel is also joined to the first main channel splitting the primary stream therefrom. An evaporative coolant is injected into the first counterheat channel, and an evaporative saturant is injected into the second counterheat channel. Heat from the initially hot primary stream in the first exchanger evaporates the coolant in the first counterheat channel for self-cooling the primary stream in the first main channel. Heat from a hot secondary stream channeled through the second main channel evaporates the saturant in the second counterheat channel for adding mass to the primary stream channeled therethrough.