Introduction - Pumps:

The true heart of any water cooled rig is the vital role of the pump which can not be underestimated. Pump specifications have dramatic effects on the overall performance of a water cooling system. While flow is the most often analyzed specification, there are also other features such as power source, head and noise levels can also contribute or detract from the system performance.

The first choice is in the type of pump to purchase, an AC or DC pump. The advantage of a DC pump is that it can be hooked directly up to the PC power supply. The disadvantage, however, is that most DC pumps are bilge pumps, and as such, are not typically designed to operate 24/7. In a water cooled system, this could result in a premature, unexpected failure. On the other hand, an AC pump, while designed to run continuously, has the disadvantage of requiring some kind of power feed outside the computer case, either by means of a pass through cable, a solid state relay, or a power supply equipped with an AC socket.

Pumps used in water cooling are not high pressure systems; rather they are designed to maximize flow. A pumps’ flow rating is typically measured in gallons per hour. Usually, the higher the flow rate of the pump the better (unless other key components are designed to function better under low flow conditions). Mid-range pumps will average around 100 GPH while high-end pumps will handle 300 or more gallons per hour. This rating, however, is not the true flow measurement the pump will perform at inside your system. Tubing, water blocks, radiators and fittings all take their toll on the maximum flow rate. As such, it is easy to loose at least 80% of the total flow rate of a pump to resistance.

One other key factor to look at in a pump’s design is the head pressure. This is the pump’s vertical discharge ability. Why is the pump’s head pressure an important specification? Because if the total distance from the lowest point in the system to the highest point in the system exceeds the pumps head, the pump will physically not be able to push water from the low point to the high point. As well, flow rates drop significantly the higher a pump has to push coolant. For example, a system at 0 feet might be able to achieve flow rates of 400 gallons or more. That same system with a five foot elevation might only pump 100 gallons per hour. Usually, users don’t have to concern themselves too much with the pump’s pressure head, although individuals with extremely large server towers should probably take special note.

Water cooling is as much about silence as it is about performance. For some users, performance even takes second place to the goal of an ultra-quiet rig. As such, another key area to investigate is how loud the pump is. The noise generated through the pumps vibration can be minimal, or can be as noticeable as a mid-ranged rotary fan. Some pumps are significantly quieter than others, and some can also be fitted with vibration dampeners to lower the total noise levels.

The pump I’ll be using in the MTB Labs is the Via Aqua 1300. The Via Aqua is the little darling of the water cooling community. Its affordable price, small profile and respectable performance make it a popular choice for those looking to construct their own custom water cooling system.

Assembled Via Aqua 1300 Pump - Key Specifications:

Assembled Via Aqua 1300 Pump: Distributed by Compuvision

Pump size: 3.75" long, 2.25" wide, 3" tall

Fully submersible

6+ feet lift with 370 GPH flow rating

Quiet running

1/2 inch fittings

 

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Click image for larger view

 

The Via Aqua 1300 is an AC pump that can either be run inline or submersed, making it a viable option for either scenario. It typically ships with 1/2 inch fittings on the inlet and outlet (more often referred to as the suction side and the pressure side), although 3/8 fittings could be substituted for systems requiring the smaller size. The head pressure on the Via Aqua 1300 reaches a maximum of 6 feet. At that level, flow rates drop down to a mere 79 gallons per hour. For most users, a 2 foot elevation is standard, and the pumps rating of over 300 gallons per hour at that level is still respectable.

Click image for larger view

Click image for larger view

 

The Via Aqua 1300 also comes with a snap on base that includes four suction feet. This provides some vibration absorption. However, along side pumps by Eheim, Swiftech and Hydor, the Via is clearly the loudest of the pumps. There are a couple of web sites that show how to modify the anti-clog feature along the shaft of the pump to minimize the noise levels, however this should be done with caution as it can seize the mag shaft if not done correctly. As was previously mentioned, the Via Aqua 1300 is one of the smaller pumps commonly used on the market. The comparison Ehiem 1046 in the picture above gives you a rough idea of the extra space savings to be had in choosing a Via pump.