Patent ID: 6974382

Claim:
In combination with a building having an enclosed space, a bottom floor, and an outside wall having an opening above ground level, apparatus for conditioning air within the enclosed space, the apparatus comprising first conduit means having an air outlet and connected to said wall opening for discharging air through said wall opening to the exterior of the building and further having an air inlet end, a fan means adjacent the bottom floor and connected to said air inlet end of said first conduit means for removing air from the bottom floor level and discharging the air through said conduit means and the wall opening to the exterior of the building, and the apparatus further comprising a humidifier connected in fluid communication with the air inlet end of said first conduit means, second conduit means having one end open to the enclosed space, and a control valve for connecting the opposite end of said second conduit means to said first conduit means between the air outlet and the air inlet end thereof, there being a single fluid flow path from said bottom floor level through said fan and said humidifier to said control valve, said control valve having a first state allowing fluid flow from the air inlet end of said first conduit means to the air outlet thereof and blocking flow to said second conduit means and having a second state allowing flow from the air inlet end of said first conduit means through said second conduit means and blocking flow to the air outlet of said first conduit means whereby when said control valve is in said first state said apparatus provides dehumidification of air in the enclosed space and when said control valve is in said second state said apparatus provides humidification of air in the enclosed space.