The invention relates generally to liquid-repellent coatings, and in particular, to porous liquid-repellent coatings, a method of preparing the porous liquid-repellent coatings, and a method of characterizing a porous surface for the liquid-repellent coatings. The invention further relates to a porous liquid-repellent coating comprising a porous layer of a transition metal oxide and/or hydroxide and a layer of a liquid-repellent compound deposited onto the porous layer of the transition metal oxide and/or hydroxide, wherein the porous layer of the transition metal oxide and/or hydroxide is comprised of a plurality of surface pores of varying angles with an average angle that is re-entrant.

A method of cooling moist air through a heat exchange surface suppresses the formation of dew and frost on a heat exchange surface by preparing a carrier which has a heat conduction ratio higher than that of the moist air if the air temperature in a temperature boundary layer, is below the dew-point when the air temperature in the temperature boundary layer is above 0 C., or below the freezing-point when the air temperature in the temperature boundary layer is below 0 C., the carrier being arranged within the temperature boundary layer and on the heat exchange surface, which is in contact with moist air and is used for cooling; and removing moisture from the air by condensing or sublimating water vapor in the moist air on the surface of the carrier by arranging the carrier opposite of the heat exchange surface and within the temperature boundary layer.

A method of cooling moist air through a heat exchange surface suppresses the formation of dew and frost on a heat exchange surface by preparing a carrier which has a heat conduction ratio higher than that of the moist air if the air temperature in a temperature boundary layer, is below the dew-point when the air temperature in the temperature boundary layer is above 0 C., or below the freezing-point when the air temperature in the temperature boundary layer is below 0 C., the carrier being arranged within the temperature boundary layer and on the heat exchange surface, which is in contact with moist air and is used for cooling; and removing moisture from the air by condensing or sublimating water vapor in the moist air on the surface of the carrier by arranging the carrier opposite of the heat exchange surface and within the temperature boundary layer.

A plate for a heat exchanger between a first medium and a second medium, the plate being associated with a main plane of extension and a main longitudinal direction and including a first heat transfer surface, extending substantially in parallel to the main plane and arranged to be in contact with the first medium, generally flowing along the first surface in a first flow direction; and a second heat transfer surface, extending substantially in parallel to the main plane and arranged to be in contact with the second medium, generally flowing along the second surface in a second flow direction. The first surface includes protruding ridges defining at least two parallel and open-ended channels extending in the first flow direction. The second surface includes a plurality of protruding dimples arranged in the channels between neighbouring respective pairs of the ridges.

Control systems are provided that provide thermodynamically decoupled control of temperature and relative humidity and/or reduce or prevent frost formation or remove previously-formed frost. The control systems herein may be included as a component of a heating, ventilation, air conditioning, and refrigeration system that includes a heat exchanger.

Control systems are provided that provide thermodynamically decoupled control of temperature and relative humidity and/or reduce or prevent frost formation or remove previously-formed frost. The control systems herein may be included as a component of a heating, ventilation, air conditioning, and refrigeration system that includes a heat exchanger.

A method of operating a heat exchanger is disclosed in which an electric field is applied to a hydrophobic surface having condensed water droplets thereon to reduce a contact angle between the individual droplet surfaces and the hydrophobic surface, and to increase droplet surface energy to a second surface energy level. The electric field is removed to increase the contact angle between the individual droplet surfaces and the hydrophobic surface, and to reduce droplet surface energy to a third surface energy level. The third surface energy level is greater than the first surface energy level and greater than a surface energy level for a free droplet. A portion of the droplet surface energy is converted to kinetic energy to detach droplets from the hydrophobic surface. The detached droplets are removed from the heat rejection side fluid flow path.

A method of operating a heat exchanger is disclosed in which an electric field is applied to a hydrophobic surface having condensed water droplets thereon to reduce a contact angle between the individual droplet surfaces and the hydrophobic surface, and to increase droplet surface energy to a second surface energy level. The electric field is removed to increase the contact angle between the individual droplet surfaces and the hydrophobic surface, and to reduce droplet surface energy to a third surface energy level. The third surface energy level is greater than the first surface energy level and greater than a surface energy level for a free droplet. A portion of the droplet surface energy is converted to kinetic energy to detach droplets from the hydrophobic surface. The detached droplets are removed from the heat rejection side fluid flow path.

A method for precise control of movement of a motive phase on a lubricant-impregnated surface includes providing a lubricant-impregnated surface, introducing the motive phase onto the lubricant-impregnated surface, and exposing the droplets to an electric and/or magnetic field to induce controlled movement of the droplets on the surface. The lubricant-impregnated surface includes a matrix of solid features spaced sufficiently close to stably contain the impregnating lubricant therebetween or therewithin. The motive phase is immiscible or scarcely miscible with the impregnating lubricant.

A method for precise control of movement of a motive phase on a lubricant-impregnated surface includes providing a lubricant-impregnated surface, introducing the motive phase onto the lubricant-impregnated surface, and exposing the droplets to an electric and/or magnetic field to induce controlled movement of the droplets on the surface. The lubricant-impregnated surface includes a matrix of solid features spaced sufficiently close to stably contain the impregnating lubricant therebetween or therewithin. The motive phase is immiscible or scarcely miscible with the impregnating lubricant.