An enclosure has a perforated front door with a replaceable filter, and a perforated rear side allowing air to flow through the enclosure. The enclosure also has mounting brackets for heat generating elements, such as line cards or other rack mounted electronics. A fan draws air through the perforated front door, though the filter, and across the heat generating elements. Side brushes are disposed on a side wall near the front of the enclosure, which allow any cables attached to the heat generating elements to exit the enclosure. The front door is removable, opening up one side of the side brushes and allowing the cables to slide in the side brushes while still connected to the heat generating elements.