Combined wall outlet with constant volume flow controllers

In office buildings the supply air is often distributed to the offices via corridor walls. Different types of wall air outlets can be used which obviate the need for a false ceiling in the offices. These outlets are connected to the supply and return air ducts positioned above the corridor's false ceiling. Usually there is little space available to accommodate the HVAC systems; in such cases it is possible to use the combined wall outlet - with integrated silencers and volume flow controllers - which has been recently developed by KRANTZ KOMPONENTEN. This outlet is made up of a rectangular housing divided into a lower supply air segment and an upper return air segment, a removable faceplate, and constant volume flow controllers integrated into the connection spigots, which operate without auxiliary energy. The outlet housing is fitted with silencers whose purpose it is to attenuate the sound power level of the volume flow controllers. These volume flow controllers are inserted from the rear into the extended connection spigots and can be removed where necessary. The faceplate is divided into a lower supply air segment and an upper return air segment with a neutral zone in between intended to prevent any collision of supply and return air.

Thanks to their high level of sound attenuation the integrated silencers also reduce the sound transmission between two adjacent rooms. In most cases this obviates the need for further silencers for such purpose.

One of the advantages of the combined wall outlet is its compact design which significantly reduces the space required for installation. Further, the installation time and cost are rather low since several parts build a single unit. Last but not least, this outlet saves costs since no silencers against sound transmission are required.

The combined wall outlet can be supplied either as a displacement outlet (Fig. 1) or as a multiplex outlet (Fig. 2) in 600, 800 or 1000 mm nominal length. The displacement outlet generates a low-turbulence air flow. The supply air temperature should not be under 16 °C. In offices having a usual height the temperature difference between supply air and return air can amount to max. -8 K. The multiplex outlet is made up of several jet bundle elements that are manually and individually adjustable and that discharge the supply air and take in the return air. The supply air jets being spread out, the jet velocity and the temperature difference between supply air and indoor air decrease rapidly. The multiplex outlet can be used for heating and cooling at temperature differences of up to +15 / -12 K. Both the displacement outlet and the multiplex outlet can be installed in buildings with concrete slab cooling or a cooling ceiling system.

The combined wall outlet has a nominal volume flow rate of between 16.5 and 25 l/s (60 and 90 m³/h). The working range of the constant volume flow controllers is about 50 to 150 Pa. The sound power level is max. 40 dB(A). The insertion loss of the outlet housing fitted with silencers is about 15 dB in average.

Besides the two combined wall outlets described above it is also possible to use the wall slot diffuser (Type WSD) whose design is to be modified for installation behind a gypsum plasterboard wall.

References:
Rheinische-Zusatz-Krankenversicherung (Health insurance company),
Cologne  (Type FA-VK-KVR)
Gemeindeverwaltung Littau (Administrative authority of Littau),
Switzerland (Type W-WK-KVR)