Abstract: An apparatus for pre-heating ventilation air for a building. The apparatus includes a first sunlight-absorbent collector panel on the building. The panel is exposed to ambient air and defines a first air collection space between itself and the building. The first sunlight-absorbent collector panel has a plurality of air inlet openings to allow the ambient air to pass through the openings to the first air collection space. A second sunlight-absorbent collector panel on the building is adjacent the first sunlight-absorbent collector panel and defines a second air collection space between itself and the building. The second sunlight-absorbent collector panel has a plurality of air inlet openings to allow air to pass through the openings to the second air collection space. A glazing covers the second sunlight-absorbent collector panel and defines an intermediary air flow chamber between itself and the second sunlight-absorbent collector panel.

Abstract: An apparatus for pre-heating ventilation air for a building. The apparatus includes a first sunlight-absorbent collector panel on the building. The panel is exposed to ambient air and defines a first air collection space between itself and the building. The first sunlight-absorbent collector panel has a plurality of air inlet openings to allow the ambient air to pass through the openings to the first air collection space. A second sunlight-absorbent collector panel on the building is adjacent the first sunlight-absorbent collector panel and defines a second air collection space between itself and the building. The second sunlight-absorbent collector panel has a plurality of air inlet openings to allow air to pass through the openings to the second air collection space. A glazing covers the second sunlight-absorbent collector panel and defines an intermediary air flow chamber between itself and the second sunlight-absorbent collector panel.

Abstract: Electrical connectors are provided including a connector body with a tubular socket to receive an electrical conductor. A clamping means is arranged to secure the electrical conductor within the socket. A socket insert fits within the socket so as to reduce the effective size of the socket. The socket insert is tubular and is adapted to be deformed by the clamping means into retaining engagement with the electrical conductor.

Abstract: Insulation-piercing fasteners are provided having a generally cylindrical shank, externally threaded along at least part of its length. The end portion of the shank is configure to engage an insulated electrical conductor and is formed with a hollowed end portion. The hollowed end portion has a generally cylindrical recess having a diameter less than the diameter of the shank. The wall of the hollowed end portion has at least one interruption. The width of the interruption is less than the maximum internal width of the hollowed end portion.

Abstract: A shearable fastener has a threaded shank (10) adapted for engagement with a threaded bore and a head (12) formed for engagement with a drive tool. The shank (10) is formed with a series of axially separated weakenings (14) defining a series of shear planes, the weakenings (14) being formed such that the applied torque necessary to cause the shank (10) to shear increases progressively from the shear plane (14) furthest from the head (12) to the shear plane (14) nearest the head (12).