Minor changes often lead to major improvements in the operating behaviour of ventilation equipment. For example, the splitter attenuators which exist in almost every ventilation and air conditioning system. The common rectangular have sharp-edged frames. The only reason why engineers haven't tried using new shapes is probably because of the price. With the same acoustic performance, splitters and complete silencers are always bought on price. Because of the air flow, so-called bull noses are used by contractors. They are designed to prevent both losses from arising through shocks during the entry and the losses resulting from the turbulence during the exhaust stage. Gebrüder Trox GmbH in Neukirchen-Vluyn, is now making this procedure dispensable. The company is equipping its splitter attenuators with rounded profile frames. This improves the intake and the exhaust conditions. According to Siegfried Walter, manager of the Equipment and Sound Technology Department at Trox, it also helps to reduce pressure loss by up to 30%. According to Walter, when you consider the blower caps which usually aren't included in tenders, the new sound absorbers are not any more expensive than the other sharp-edged cheaper products. Beyond that, the absorption-material is from biodegradable mineral wool which does not pose a health hazard and which can also be recycled. The surface is covered with non woven glass fibre fabric (standard construction). Since the modified sound absorbers can compete on price, the competition will also have to develop comparable products according to Walter.