A heat transfer apparatus includes a wetting chamber, an air intake opening leading to an air flow pathway through the wetting chamber, an air outtake opening leading from the air flow pathway through the wetting chamber, an atomizer, a liquid reservoir, and a liquid delivery system for moving liquid from the liquid reservoir to the atomizer. The atomizer is arranged to receive the liquid from the liquid delivery system and disperse the liquid into the air flow pathway in a form of atomized liquid, and the liquid reservoir is disposed to collect the atomized liquid from the wetting chamber.