Office-based servers and active equipment and their cooling methods have become more powerful and inevitably noisier, leading to distractions and an uncomfortable workplace. Reduction of the noise generated within Data Network Cabinets by this equipment is significantly beneficial for a pleasant and efficient working environment, particularly where the cabinets need to be sited within working offices.
Meeting/conference rooms, School classrooms, retail and general public access areas also will benefit. Server rooms that need overall soundproofing of the room will need soundproof cabinets where large numbers of cabinets may generate such significant noise levels to make necessary working and communication within the workspace difficult. Soundproofing the cabinets may well make the necessity for complex soundproofing of the overall room redundant! It is therefore clear that in these situations keeping the server rack or server room generated sound to a minimum vastly improves the working environment promoting optimum comfort, and productivity.
Acoustic soundproof server cabinets can reduce audible server and general equipment noise by between 25 and 28.5 dB to the levels lower than typical office background sounds. However, we recommend soundproofing cabinets using a multilayer composite of sound barrier laminated with acoustic foam on all inside surfaces, reducing the noise between 25dBA and 28.5dBA.
Noise levels are measured in decibels (dBA) so if we have, say, 25dBA noise reduction this is the amount of noise removed from the source, as an example if we take the noise of a vacuum cleaner at around 75dBA and reduce to 50dBA that would reduce the sound level to about that of quiet speech. Additionally, it is vital to minimise general noise and filter out noise that is unpleasant to the ear, known as psychoacoustic noise – acoustic cabinet design filters out these undesirable frequencies, ensuring the audible noise is as low level and non-intrusive as possible.
Here is a link to a Decibel (dBA) chart for some typical sound levels.
To soundproof a server cabinet or server room, planning for Acoustic noise reduction becomes very important, as does the need for choosing a Passive or Active Soundproof Server Cabinet.
A Passive Acoustic Cabinet relies solely on the equipment fans for passive cooling. It will dissipate up to 2.5Kw of generated heat, making them suitable for devices such as network switches and UPS with a total power consumption of 1.5Kw. Temperature differentials between the internal cabinet and room draw air in from the front of the cabinet, passes it over the equipment, before being expelled at the rear.
An Active Acoustic Cabinet has variable speed fans either on the roof or on the rear doors to deal with increased heat loads, so are ideal for servers, blade servers, or other devices with an overall heat output above 1.5Kw. Soundproof server cabinets with active cooling can dissipate up to 12kW of heat load in a 42U cabinet.
To specify an Acoustic Soundproof Network Server Cabinet, first determine the following:
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If passive equipment such as patch panels, with no likelihood of other active equipment with or without fans, is installed, extra soundproofing is not needed.
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If active kit with or without internal fans and integral Cabinet fans required for heat extraction – then sound reduction methods are advisable.
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Is the heat generated by the equipment likely to always be below 1.5Kw (1.7Kw total consumption by equipment) - if so a Passive cabinet should be acceptable
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Is the heat generated by the equipment likely to be above 1.5Kw? - then an Active cabinet is required.
What are the best ways to reduce noise emanating from the cabinet?
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Specify a cabinet fitted with Acoustic sound-absorbing cladding to internal surfaces. This acoustic cladding is usually a heavy layer of sound barrier membrane with fire retardant acoustic foam laminates on both sides.
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The necessity for cabinet fans will depend on the heat generated, if it is below 1.5Kw, they may not be thought essential, and a Passive Cabinet should be acceptable. However, it then becomes vital to install the equipment & manage the cabinet cabling to ensure no obstructions to cause hot spots within the cabinet. It is best practice to pay attention to cabinet layout and fit cooling fans with a temperature-sensing thermostat to cover all eventualities.
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The main reason for the noise is fans running to dissipate heat from the fitted equipment, and this heat will need to be expelled from the enclosure without compromising the sound reduction properties of the cabinet. An Active Cabinet with low noise fans and an air baffle system to reduce extra airflow noise achieves this. When installing equipment and cabling, it is essential to manage this is such a way as to avoid possible hotspots caused by disruption to the airflow. The heat generated can be expelled into the room – or, in particular within enclosed data rooms, ducted away to avoid overall room temperature increase. Other cooling methods such as Air Conditioning or water cooling are possible as well as upgrading the IP rating to IP54 to minimise dust/water ingress.
