Belimo ball valves key to energy-efficient air-conditioning refurbishment
Belimo’s motorised characterised-control valves provided the solution to the energy-efficient refurbishment of controls of the induction air-conditioning system in the ZDF building at Mainz in Germany.
Both operating and energy-efficiency benefits have been gained using Belimo characterised-control ball valves in the refurbishment of the induction air-conditioning system in the 16-storey building of German broadcasting company ZDF in Mainz, Germany. Pneumatic sequence valves had been used for the single-room control of the 850 rooms in this building for 30 years. Problems with these old valves pointed to only one solution — their replacement. Among the problems were very inaccurate regulation, with the slightest changes in settings causing large changes in temperature. Some valves were not operating at all. There was also a certain amount of unavoidable heat exchange due to the simultaneous flow of cold and warm water through a common valve body. Large temperature differences between the north and south sides of this exposed building required both heating and cooling to operate for most of the year. Particles in the system water could also cause valves to jam. The induction units could not be replaced because of the amount of work involved making costs prohibitive. Some 10 000 new valves were required, so confidence in the chosen solution was very important. One solution investigated was based on Belimo motorised characterised-control valves. A test room was fitted out with these valves and their performance monitored for six months. They satisfied the criteria of not jamming, being insensitive to dirt, robust but compact design and being available with appropriate Kvs values. When these ball valves are closed they are air-bubble tight — avoiding the wasteful leakage of energy that had previously been inevitable. This feature alone is said to have delivered an 18-month payback on the extra cost compared with conventional globe valves. Additionally, the much more accurate control of room temperature following their installation has made a significant impact on energy consumption and made the offices noticeably more comfortable.
Related links:
