Interesting no-pump approach – Kevin Lura
Water cooling has seen several very nice improvements recently that are making systems more efficient than ever – several new pumps and a water block that is being brought to the main stream by a nice collaboration between Swiftech and Little River.
The problem I see, however, is that these high performance parts are costing top dollar and many systems are running several hundred dollars when everything is added up. I love water cooling as much as the next guy but I don’t see the gains from these top dollar systems that I would like to.
So here is my solution: In my opinion, water cooling attracts people for the following reasons:
- Satisfaction from a DIY project
The last point, I feel, has become a lost art; scroll down the water cooling section on Overclockers.com to see what I mean – DIY cooling setups are all but disappearing.
I have used half a dozen water pumps trying to find one that suits my needs – quiet and silent. My favorite so far has been the Ehiem compact which I feel should replace the Via Aqua as the low-price king. However, none lived up to my standards, so I got rid of them.
Obviously this puts a large dent in the performance of a water cooling system. A good air cooling system could compete with a pumpless system and have a similar noise level and lower price. To make up for this, I used a thermal electric device.
Thermoelectric devices have somewhat of a bad reputation. In the process of researching for this setup, I found a lot of misinformed people about the uses of thermoelectric devices.
Peltier devices generally have a very low efficiency that makes them difficult to deal with. With such a low efficiency, large cooling loops and dedicated power supplies are necessary to run them. To deal with this, I run my TEC at a lower voltage, 5 volts; this allows me to cool my CPU but only draw 5 volts @ 10 amps.
At this power, I do not need a large radiator or a dedicated power supply. A large TEC must be used, as running it at a lower voltage increases efficiency but decreases capacity. I choose a 320 watt unit from eBay.
Here is my original setup:
- Ehiem compact
- Bonneville heater core(dual 120 mm heater core)
My setup with TEC:
- 320 watt TEC
- Chevette heater core (single 120 mm heater core)
The heater core must be horizontal and on top of the case; the water block must be vertical and on bottom for water flow to be established.
With the original setup, I was getting a load of 42ºC under Prime95; with the new setup, I get the same 42ºC. My idle temps have changed from 32ºC in the first setup to 24ºC (below ambient but above dew point, so condensation is not a problem ATM) with this setup. Ambient room temp is 26-27ºC.
There are several things to take into consideration when looking at the temps:
- The legitimacy of my testing is bound to come up. I can accept this but I believe it is undeniable that I have a functional and competitive setup here
- Decreased area on the heater core will show an increase in temp, especially with the added heat from the TEC. I will be putting the Bonneville back in shortly
- I do not believe that water is the best coolant for this setup and I plan on purchasing and testing other coolants. I have researched some coolants and I believe I can get a decrease in temps with other coolants
I am hoping the points above will make this system a top performer.
Total cost for me was:
- $18 for the block
- $21 for the TEC
- $7 for a Chevette heater core from the auto parts store (I already had this)
Total = $56
Comparing that to the latest water block priced at $76, this is obviously much cheaper than many systems built today.
A pump can, of course, be added to this system. My view: of course you can add a pump and get another ~15ºC drop in temps. This is like anything – of course you can make it better, but where do you stop?
- If you add a pump you get ~15ºC drop
- Then you have to insulate
- If you’re insulated, you might as well run full voltage to the TEC
- Running the TEC at full voltage requires a separate PSU
- More heat from the extra volts to the PSU means you should probably add another HC/rad
- More HC/rad means you can benefit from another pump
- Etc, etc
You can pretty much play that game until you’re broke. I believe my system is the best performance for the dollar you can get as well as the quietest system you can build.
Kevin Lura – aka Ls7corvete