Flat panel contactors and methods

A flat panel contactor for an air handling, ventilation or duct system comprising:

• a frame having a top member, a bottom member, and two side members, the members defining an open front port and an open back port, the frame has at least two side ports extending from one side member;
• a first headspace adjacent the top member;
• a second headspace adjacent the bottom member;
• a hollow fiber membrane array located between the top and bottom members, between the side members, and between the front port and the back port, the array has multiple layers of hollow fibers, each layer has between 10-58 fibers per inch, the hollow fibers are held together with a supporting thread, the hollow fibers have a plurality of pores with an average pore size of 0.03-0.04 microns, and lumens of the hollow fiber are in fluid communication with the headspaces;
• wherein the array has a gas pressure drop less than 0.5 psi per 1000 SCFM.