AU2011100026A4 - LED Downlight Gimbal Seal - Google Patents

Abstract

Abstract The disclosed dust, insect and air trap is comprised of an open ended tube made from materials such as silicone or other materials that may lend themselves to be elastically constricted at both ends to create a tight seal against the frame and lower heat sink of an LED recessed downlight luminaire so as to provide a barrier to eliminate air conditioning losses while stopping the ingress of dust and insects into the living areas of the installed environment. Page4of

Description

Recessed LED Gimbal Downlight Dust, Insect and Air Trap Submitted by Phil Delich, Lumitex Limited A device for improving a recessed LED downright luminaire to stop the ingress of dust and insects while also eliminating air conditioning losses. Overview Recessed downlights have become a very popular method to illuminate homes and businesses. A feature of many recessed downlights is their ability to swivel, by means of a gimbal mechanism. The gimbal mechanism that allows the fixture to swivel carries with it three problematic issues; 1) Dust and other airborne particulates built up in the roof space constantly pass through the gap around the gimbal mechanism, falling into the living areas of the room. This dust is of particular concern to allergy sufferers. "Blow in" insulation popular in recent years has created an additional ongoing source of fine particles entering living areas through gimbal light fixtures. 2) Spiders and other insects can pass through this gap into the living areas. Many people have a fear of spiders and insects entering their living areas, with venomous varieties of greatest concern. 3) Airconditioning losses accrue for each additional fixture in an installation. While one small gimbal gap may not reveal critical losses, an average home containing seventy or more fixtures will lose a significant amount of heating and cooling energy. Air Conditioning Losses in Relative Terms An average gimbal downlight has a gap of approximately 2mm around the frame. This equates to a hole in your ceiling of approximately 244mm 2 , or around 17.6mm in diameter. If a home or business has 70 downlights in the ceiling, the combined total of these gaps are equivalent to having a large hole in your ceiling of around 147mm in diameter, creating a significant loss of energy in a temperature controlled environment. Some downlight frames are manufactured with a larger 3mm gap. Page 1lof Prior Art Halogen lamps, due to their compact form, have previously been available in a sealed gimbal albeit at a considerably higher cost than a standard non-sealed fixture. However, since the arrival of LED downlights the previous methods of sealing the gimbal cannot be applied. This is due to critical thermal management necessary for LED lamps compared to the halogen lamp, as well as the need to stay within the industry standard 92mm cut-out size. LED lamps contain a significantly amount of alloy in the form of a heatsink due to the need to extract heat from the LED devices. The aluminium heatsink cannot be contained in the small form enclosure that previously allowed halogen lamps to be sealed and gimballed, as the heatsink requires air circulation to permit effective thermal management. Poor thermal management is proven to dramatically reduce the lifetime of an LED light, hence the need for a novel method to seal the fixture without compromising the thermal management, all without exceeding the 92mm industry standard frame size. LED heatsinks do not reach combustible temperatures, so there is no fire risk associated with the fitting or the proposed modification. A simple, effective and low cost means of solving all three issues is described below. Page 2 of 7