Tjernlund Products Inc, White Bear Lake, Minnesota, offers a pair of energy-saving fans that are capable of automatically and simultaneously ridding basements or other areas of stale air and drawing in fresh outside air. The Xchanger comes in model X2D and model X2R. The former is designed for mounting directly next to an outside wall, while the latter can be connected to the outside intake/supply hood with six-inch ducts. Both models feature two reversible 90 CFM fans that can be positioned to move air in either direction.
Tjernlund www.tjernlund.com