With MIREL evolution, Zumtobel is steering louvre luminaires towards modern times. By giving the luminaire a distinct appearance, Zumtobel has mastered the challenge of integrating energy-efficient LED technology into a tried-and-tested stylistic idiom: the lenses and the light source of MIREL evolution are visible to the user and are thus becoming a key design feature of the otherwise minimalist luminaire. Thanks to the particular shape of the lens, a directional beam pattern and a brilliant appearance are achieved without any annoying glare. Light distribution is effected via the lenses at a rate of 95 per cent; only 5 per cent of the luminous flux are reflected by the “louvre”. This results in more precise direction of light and higher luminous efficiency, which is also indicated by a luminaire efficiency factor of 112 lm/W. The luminaire's luminous flux levels and module sizes, however, have not changed as compared to the classic recessed luminaire. Conventional luminaires can be replaced on a one-to-one basis, which is a convincing argument in favour of using MIREL evolution in refurbishment projects. The stylistic idiom of MIREL evolution featuring an opal optic has been reduced even further, so that the luminaire now appears as a flat, level luminous panel. For the version fitted with an opal cover, a 3Dprotect® reflector is used, which not only ensures perfect direction of light but also protects the sensitive LED modules during installation. Due to the interplay of innovative LED technology and direction of light in MIREL evolution fitted with an opal cover, a luminaire efficiency factor of up to 123 lm/W is possible.