The unique Lossnay heat-exchange technologies developed by Mitsubishi Electric help refresh a room's air while leaving temperature and humidity largely unchanged. The Lossnay core is comprised of a diaphragm constructed of specially processed paper configured into a cross-flow, plate-fin structure. The advanced heat-transfer and moisture permeability properties of the paper help maximize the recovery of heat as air is circulated through the element. The result is substantial energy savings and a more comfortable indoor environment. Lossnay ventilators can be used alone or in combination with other air conditioning/ventilation systems.