The first thing that struck me when the system was turned on was the noise level. One person walked into the lab and asked "what is that?" There are two 120 mm fans on either side of the case inducting and expelling air past the elaborate cooling solution. While the two ADDA (AD1212LB-A73GL) fans are rated for 34.4 dBA (decibels) - the same as a smaller office - the configuration seems to have had an impact on the noise. The two fans working together would theoretically only produce about 37-38 dBA, but they were certainly the main noise source. There are also four other fans in the system, one for the PSU, one for the Northbridge, and two 14 dBA case fans.

One possible explanation could come from the image below. While the 120 mm fans should only produce a low amount of noise under normal pressures and flow, the edge of the fans' blades are blocked by the cooler. The far edge of the blade is the point at which the fan is spinning the fastest (travelling the furthest distance compared to the center of the fan). This is also should be the point with the highest compression. This air is being impeded and forced to flow backwards out of the case. The mesh used on this system could also be having the effect of adding to the noise we hear. Without a sound chamber on site it would be hard to determine the exact level of the noise we heard during operation, but it could be classified as being equal to a conversation. That being the case, if you want a quiet system, this isn't it, at least in its current form.

One suggestion we would make for the final design of the system would be to use both fans attached to the cooler to expel air out of the case, not one in and one out. This would force cool air into the case via the other two case fans, and then force air across the fins of the cooler and out of the case. The current configuration brings air in via the two case fans but also via the right side's cooler fan. We are not sure that the cooler is getting enough air to flow across its fins, and the air flow alteration would force air to flow out the bottom of the case through the PSU and cooler fans.

Water pump and control board for the pump, Peltiers, and fans.

In a conversation with Biohazard, the company stated that it will be changing some aspects of the design for the final production. The first is that a higher air flow mesh will be used instead of the one used on the prototype build we received. They also will be adding another case fan at the bottom of the case "to provide additional cool air to the PSU."