SilentMode Acoustic Enclosure for OCHSNER Table evaporator

Initial position
An OCHSNER heat pump from the "AIR-85-C14A" model series was used as part of a renovation project. The outdoor unit is designed as a table evaporator. The system has the following dimensions: 2,225 x 1,940 x 1,340 mm L x W x H. The system has 2 axial fans with a maximum volume flow at full load of 20,000 m3/h.

The heat pump is located outside of a kindergarten in Stuttgart.
 
Acoustic enclosure concept 
The basic structure of the acoustic hood is an aluminum plug-in profile frame, the service doors around the system are integrated into this profile frame. The service doors are based on aluminum panels with a thickness of 1.5 mm with internal 40 mm thick insulation made of Stratocell® Whisper, the material has one of the best sound-absorbing properties available on the market.
 
The acoustic hoods have the following dimensions: 2,800 x 2,500 x 1,700 mm (L x W x H) with a weight of 375 kg.
The air openings and the free air inlet openings are designed with around 15% above the required air volume of the system. The air flow is offset to the sides, so that no air short circuit can occur between the exhaust air and supply air. With the air deflection by 90°, the airborne sound is broken, which leads to a significant reduction in the exit noise. The air outlet speed is around 1.98 m/sec.

Noise reduction
The all-round noise reduction across the frequency spectrum from 63 to 8,000 Hz is between 19 and 20 dB(A), with a pressure loss of around 20 Pa.
 
Adaptation to the environment
The acoustic hood was made entirely of aluminum and powder-coated in the RAL color: 5022 (night blue).

Additional Information
info@silent-mode.com
​www.silent-mode.com (German)
www.silent-mode.net (English)
www.silent-mode.it (Italian)

Acoustic enclosure for OCHSNER Table Evaporator View from Air Inlet Side.

Acoustic enclosure for OCHSNER Table Evaporator View from Air Outlet Side.