Abstract: The within invention improves on the indirect evaporative cooling method and apparatus by making use of a working fluid that is pre- cooled with and without desiccants before it is passed through a Wet Channel where evaporative fluid is on the walls to take heat and store it in the working fluid as increased latent heat. The heat transfer across the membrane between the Dry Channel and the Wet Channel may have dry, solid desiccant or liquid desiccant and may have perforations, pores or capillary pathways. The evaporative fluid may be water, fuel, or any substance that has the capacity to take heat as latent heat. The Wet Channel or excess cooled fluid is in heat transfer contact with a Product Channel where Product Fluid is cooled without adding any humidity. An alternative embodiment for heat transfer between adjacent channels is with heat pipes.

Abstract: A compact power hammer that can be used to drive post easily and safely by one person as well as for use with other impact tools. The invention is comprised of a cam (26) lifting a hammer (44) and dropping it onto an anvil (30). The impact on the anvil (30) is transferred to the post (56) or impact tool by way of the center tube head (58). The center of gravity of the impact device (10) is below and in the post or impact tool 56.