A glass unit comprising: (a) a spacer defining a perimeter of the glass unit, wherein the spacer has a front side, a back side, an interior perimeter edge and an exterior perimeter edge; (b) a front glass pane attached to the front side of the spacer; (c) a back glass pane attached to the back side of the spacer, wherein the front glass pane and the back glass pane are maintained by the spacer in a spaced-apart parallel relationship which defines an interior space of the glass unit between the front glass pane and the back glass pane; and (d) a pressure equalization conduit defined by and within the spacer, wherein the pressure equalization conduit has a first end and a second end, wherein the pressure equalization conduit is in fluid communication with an exterior of the glass unit at a first end port which is adjacent to the first end of the pressure equalization conduit, wherein the pressure equalization conduit is in fluid communication with the interior space of the glass unit at a second end port which is adjacent to the second end of the pressure equalization conduit, and wherein a desiccant is contained within the pressure equalization conduit, characterized in that the pressure equalization conduit is continuous between the first end port and the second end port so that a fluid can transfer through the pressure equalization conduit between the exterior of the glass unit and the interior space of the glass unit only at the first end port and the second end port, wherein the pressure equalization conduit extends within the spacer more than once around the perimeter of the glass unit, wherein the spacer defines therein a plurality of channels extending around the perimeter of the glass unit which are connected together in a series configuration, and wherein the plurality of channels provide the pressure equalization conduit. (a) a spacer defining a perimeter of the glass unit, wherein the spacer has a front side, a back side, an interior perimeter edge and an exterior perimeter edge; (b) a front glass pane attached to the front side of the spacer; (c) a back glass pane attached to the back side of the spacer, wherein the front glass pane and the back glass pane are maintained by the spacer in a spaced-apart parallel relationship which defines an interior space of the glass unit between the front glass pane and the back glass pane; and (d) a pressure equalization conduit defined by and within the spacer, wherein the pressure equalization conduit has a first end and a second end, wherein the pressure equalization conduit is in fluid communication with an exterior of the glass unit at a first end port which is adjacent to the first end of the pressure equalization conduit, wherein the pressure equalization conduit is in fluid communication with the interior space of the glass unit at a second end port which is adjacent to the second end of the pressure equalization conduit, and wherein a desiccant is contained within the pressure equalization conduit, characterized in that the pressure equalization conduit is continuous between the first end port and the second end port so that a fluid can transfer through the pressure equalization conduit between the exterior of the glass unit and the interior space of the glass unit only at the first end port and the second end port, wherein the pressure equalization conduit extends within the spacer more than once around the perimeter of the glass unit, wherein the spacer defines therein a plurality of channels extending around the perimeter of the glass unit which are connected together in a series configuration, and wherein the plurality of channels provide the pressure equalization conduit.