Performance data of heat transfer and flow resistance are presented for the continuous heating of air in several experimental variations of a new type of perforated-plate heat exchanger. These exchangers consisted of sections built up by stacking multiple units of a perforated aluminum plate and a neoprene gasket, to form parallel channels perpendicular to the plate faces. Tests were conducted by causing air to flow countercurrently through these passages. The effects of hole diameter, plate thickness, and gasket thickness (or plate separation) are indicated. Results are presented jointly in the form of a pressure-drop efficiency factor versus Reynolds number for portions of the range between 800 and 4300.