SILENT-H DOUBLE Acoustic enclosure FOR A CASCADE OF 2 SAMSUNG INVERTER OUTDOOR UNITS WITH HORIZONTAL AIR DUCT

Initial position
Both projects involve enclosing 2 Samsung inverter outdoor units that have already been installed. The systems each have two axial fans with a maximum air volume flow of 7,200 m3/h (full load). The static pressure of the fans is a maximum of 20 Pa. 

The system is located in the Swiss canton of Bern.

Acoustic enclosure concept
The basic structure of the acoustic hood is an aluminum plug-in profile frame, the service doors around the system and in the roof are integrated into this profile frame. The acoustic hood was installed on site without screws by simply plugging the prepared modules together. To protect against high wind loads at the exposed position, the corner connectors were also screwed on so that the sound hood remains in position even with hurricane force. 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. Because the laminated polyethylene foam absorbs sound and does not reflect it, it is an excellent alternative to many soundproofing materials used today. The insulation is also moisture-resistant, does not build up mold, can be rinsed off with a high-pressure cleaner and corresponds to the fire protection class: B-S2-d0 (hardly inflammable).

Acoustic enclosures dimension
The base frame for accommodating both systems has the following dimensions: 2,900 x 1,450 x 1,800 mm (L x W x H) with a weight of 140 kg. The sound hood was made entirely of aluminium.

Airflow
Due to the small distance between the condenser and the wall, the supply air enters from the side at the rear. The air outlet is at the front and upwards with an air deflection of 90°. The acoustic hood is designed for an air flow rate of 15,000 m3/h. The ~air outlet velocity is 1.69 m/sec. so that we hardly transmit any sound.

Noise reduction and pressure drop
The all-round noise reduction across the frequency spectrum from 63 to 8,000 Hz is between 15 and 16 dB(A), with a pressure loss of < 15 Pa. air short circuit An air short-circuit between the warmer air entering and the colder air outlet is avoided by using a partition made of plastic plates with a high rubber content located at the front edge of the units. With this partition, the air chambers are hermetically separated. The high rubber content of the plate means that no vibrations from the systems are transmitted to the sound hood frame.

Right next to the cascade sound hood is one of our sound hoods for a Samsung VRF system, which was designed according to the same concept.

For more information: info@silent-mode.com