a simple climate control device is disclosed which can independently , or jointly , to the degree desired , ventilate and / or dehumidify and / or cool a dwelling . the device provides a way of supplying fresh outside air to a building or other space at a preferred humidity level while optionally cooling the inside air , and as desired dehumidifying the inside air to maintain the inside environment at a preferred temperature and at a preferred relative humidity , with gradual displacement of stale air by fresh air .