Light and illumination
For lighting purposes the lighthood is installed on the top of the display case. It is the perfect solution for any display case design invisible from the top with a depth measuring at least 200 mm. The lighthood replaces the top glass panel. Its standard height is 150 mm.
Inside the lighthood the required amount of light sources is introduced, with a dimmer on request, with concealed low voltage halogen spots or fiber optic lighting. For safety reasons access to the lighthood is from the top. Ventilation slots with covers against undesired light spill through to the top provide the necessary air exchange.
Access is normally by a hinged steel lid, locked with security locks, and incorporating ventilation louvers. If a display case is built into a wall, it should have an access panel to provide access to the lighthood. Access to the lamps should never touch the inside of the exhibition space. The lids are supported in the open position for re-lamping or spot lamp adjustment by gas struts, in appropriate dimensions for different sizes and weights of lid, or lid stays. The lids are removable for servicing work, which is more safely performed on a bench than above the display area. Between the light fittings and the display area a laminated glass dust shield is placed which can incorporate a PVB ultra violet filter, limiting UV to < 75 µw / lumen.
Below the dust shield a movable steel suspension frame can be fitted. This can be used for hanging objects, graphic panels and the like. As space is rather limited, the underside of the top lid is commonly sprayed white to act as a reflector for fluorescent battens.
The final layer is a louvre, the most commonly employed being:
- Plastic parabolic egg crate louvre
- Aluminium egg crate louvre.
- Koolshade, a laminated glass sandwich with a micro louver in the centre.