An air heating cooling and dehumidification device for maintaining room air at a desired humidity and temperature includes an air to air cross flow heat exchanger (105) formed with cross flow first and second air flow paths (A) and (B), a primary air to liquid heat exchanger (110) in fluid communication with a liquid cooling fluid source (150) for dehumidifying air flow and a secondary air to liquid heat exchanger (115) for reheating the air flow after dehumidification.