US Patent 8627673 Atmospheric water harvesters

An atmospheric water harvester includes a cooling member over which humid air flows to condense moisture from the atmosphere. The cooling member may be the evaporator of a conventional, gas vapor-based refrigeration circuit. If a gas vapor-based refrigeration circuit is used, the compressor of the circuit may be variable speed. A fan or impeller used to move air through the system may also be variable speed. A preferred embodiment includes a variable flow geometry thermal economizer section configured such that, to varying degrees, the incoming air may be pre-cooled, before it passes over the cooling member, by heat exchange with colder air that has already flowed over the cooling member.