A drastic reduction in heat build-up in the windows of Leeds Jeweller John Dyson was one of the key motivators for the upgrade in lighting to Parify Prail 40-4, with a 30 degree beam angle. The enclosed window corridor of the store was accessed both morning and night by the staff and in summer the temperature of this corridor was between 35 and 45 degrees celsius. The old Metal Halide lamps, with 15 degree beam angles gave such a concentrated beam, that all of the light was focused in an area of just 300mm in diameter, consuming over 3885W per hour.
The concentration of this light, together with the heat and high UV levels, meant that John Dyson Jewellers were regularly discounting watches and straps due to bleaching. In one instance, £4000 was discounted off several watches.