Case Cooling and Noise
Overall Case Ventilation
In addition to the obvious styling enhancements, Cooler Master has made several changes to the cooling systems incorporated into the Cosmos S enclosure. The new chassis comes with three 120mm and one 200mm case fans pre-installed. And there are three more blank locations for mounting additional 120mm fans if desired.
Pre-Installed case fans:
• Side Intake: 200mm 150 CFM
• Front Intake: 120mm 50 CFM (with red LEDs)
• Rear Exhaust: 120mm 50 CFM
• Top Exhaust: 120mm 50 CFM
Optional case fan locations:
• Bottom panel: (1) 120mm (with dust filter)
• Top panel: (2) 120mm
The Cosmos S chassis now includes three openings in the top panel (the original Cosmos 1000 had two). Since the top of the chassis is located well below the top of the case, fans can be mounted either above or below the top of the chassis. And using LED fans on top will add some nice lighting effects to the case.
The three top fan locations are well suited for installing a single, dual, or triple fan radiator for enthusiasts planning to incorporate water-cooling into their system build. In this case, mounting the radiator below and the fans above, works out great.
The Cosmos S comes with three Cooler Mater labeled 120mm case fans (A12025-12CB-3BN-F1) pre-installed. By looking up the UL code we see this fan is made by Chang Feng Electronics Co. Ltd. (DF1202512SELN).
• Model number: DF1202512SELN
• Size: 120x120x25mm
• Voltage: 7~13.2 VDC
• Speed: 1,500 rpm
• Airflow: 50.4 CFM
• Pressure: 1.93 mm H2O
• Noise: 25.6 dBA
Note 1: I measured the fan speed of the rear exhaust fan with an optical tachometer and found it was turning at 1,262 rpm @ 12 VDC.
Note 2: The 120mm fan used on the HDD cage (A12025-12CB-3KN-F1) has clear plastic blades and four built-in red LEDs.
Video Card and Motherboard Cooling
The single 200mm Cooler Master labeled fan mounted into the left side panel has nine blades and is rated for up to 150 CFM at 900 rpm when operating on 12 VDC. This fan is used to blow cool room air into the enclosure. It can move a lot of air and generates more noise than the smaller case fans. Unfortunately there is no speed control provided. Combined with the intake from the front HDD cage fan, the combined airflow into the case far exceeds the exhaust out, resulting in a positive pressure inside the case. And since the air intake points have dust filters, this will help keep the dust bunnies from building nests inside your fancy enclosure.
Internal HDD Cooling
While many users appreciated the storage capacity (6 HDDs) and convenience of the original Cosmos 1000 chassis, it didn’t provide much in the way of cooling to the installed drives. Cooler Master has completely redesigned the internal HDD cage in the Cosmos S and it now features a 120mm fan blowing directly over the drives mounted in the 4-in-3 drive cage.
Sound Pressure Levels (Noise)
Sound pressure level readings were taken 3’ away from the Cosmos S case with an average background noise level of 28 dBA. (Note: To get my basement lab this quiet requires turning off the furnace-A/C blower, unplugging the refrigerator upstairs, shutting down all the test computers, and with no one else moving in the house.)
Noise is a relative term. What is perfectly acceptable to one is annoying or unacceptable to someone else. With that said, I found the Cosmos S to be relatively quiet and acceptable by my standards for a high-end gaming enclosure. However, it is not silent and I wouldn’t use it for a HTPC. Adding speed controls to one or more of the case fans (particularly the 200mm side fan) will allow each user to fine tune the system to their personal tastes. Overall, Cooler Master has done a very good job of balancing effective case cooling with noise.
