Your basement should have cold air intake for the furnace/water tanks. Mine actually has 2, one for the furnace directly then another one drops by it for fresh air for the other gas appliances.any help with Bringing fresh in to a grow tent In a basement discretely besides a window? Plus cold Canadian winter air affect on roots in winter ? 4x4 tent 600 watt hps 4in filter fan combo, rooms dialed in just want fresh air