- What Is a Water Block?
- Choosing the Water Pump
- More To Come...
Choosing the Water Pump
The most important factor in choosing a water pump is noise. Hydor makes a very quiet pump that is also compact enough to fit into our case. Hydor is an Italian company that makes water pumps for aquariums and ponds. In fact, the "Hydor L" pump you buy for CPU water-cooling is actually a "Hydrogarden L." It's used to drive fountains for gardens. The great thing about these pumps is that they're submersible; if you wanted to design a cooling system with a big reservoir, you could submerge the pump. The water dampens the noise even further.
You should also consider flow rate when buying a pump (see Table 1). For our system, the Hydor L20 provides adequate water flow (see Figure 2). It's also the quietest. If you're doing heavy overclocking, consider a faster pump. Hydor pumps come in L30 and L40 flow models as well; these are bigger and louder, but pump faster. Faster flow means faster heat exchange and lower CPU temperatures. For comparison, Table 2 shows that the Hydor L30 pumps at a significantly higher flow rate.
Figure 2 A Hydor L20 garden fountain water pump is ideal for a water-cooling system.
Table 1
Flow of our Hydor L20 water pump under different capacities. Capacity is measured in terms of the maximum height of a column of water that can be pumped (Source: Hydor.com).
Flow (Gallons Per Hour) |
Head (Ft.) |
181 |
0 |
165 |
0.67 |
148 |
1.32 |
125.4 |
1.98 |
103.2 |
2.64 |
79 |
3.3 |
35 |
4 |
0 |
4.3 |
Table 2
The Hydor L30 pumps at a higher flow rate. However, it's also bigger, louder, and more expensive.
Flow (Gallons Per Hour) |
Head (Ft.) |
336 |
0 |
307 |
0.82 |
278 |
1.65 |
246 |
2.47 |
214 |
3.3 |
180 |
4.12 |
136.2 |
4.9 |
79.4 |
5.77 |
0 |
6.6 |
Ours is a 115-volt model. If you want the pump to turn on and off when your system does, your best option is to get a 12-volt water pump from another manufacturer. However, these can be more expensive. As an alternative, one reviewer recently tested an automotive fuel pump to see if would work. Unfortunately, he found that fuel pumps use an agitating motion that was unsuitable for water-cooling a CPU. In addition, the back-and-forth motion of the pump shook the entire case and generated a lot of noise.