A dry-type electrical transformer system comprises a transformer and a housing. The transformer includes vertically oriented primary and secondary windings, a core extending through the primary and secondary windings, and top and bottom core clamps securing the top and bottom of the core. The housing includes a base supporting the transformer and having an air inlet, a top including an air outlet, and side walls around the transformer, wherein the housing facilitates air flow through air passages in the windings driven by natural convection in the absence of a powered air mover. Support beams allow air into a base of the housing, and the clamps are designed to allow efficient air flow into and through the air passages in the windings. A top of the housing divides the air flow into separate streams and directs the air to separate vents that release the air vertically upward.