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ferdb · 09-23-2004, 10:08 AM

I've had several Koolance systems and modified them for better performance and efficiency, however those were all Case versions, not Exos. The Koolance cases have a major problem with the way airflow was set up, It's very restrictive and it also sucks hot exhaust air back in through the radiator. Oddly enough the reason they set up the airflow this way was because the pair of submerged pumps they use run off AC, and they use a transistor circuit and transformer on a controller board to generate this AC from the 12Vdc line. This controller board gets HOT, so hot in fact that without substantial airflow past it the thing melts down. The airflow path in the Koolance cases is deflected and diverted with a plastic sheet so that sufficient airflow ends up flowing past the controller board mounted on the rear roof of the case. If you remove the sheet to improve the airflow you will fry the controller board if you don't provide some other means of providing airflow to it. The simplest way to do that is use a power supply with a bottom fan such as an Enermax. Flip the supply over (you may need to file the mounting bracket a bit to get it to fit) and you will now get enough airflow past the controller board to keep it from overheating.
Now you can rip the Plastic airflow director sheet out and flip the fans over so they are all pulling air out of the case. This will substantially drop the temps of the water cooling system (as much as 10C or more) it also now will pull plenty of air past the harddrives to keep them cool (the Harddrive water blocks are a bad idea, I've lost several drives using them). You can now run the fans much slower and quieter and still achieve lower temps than before. Also you now have lots of airflow over the motherboard and cards where before there was almost none, unless you installed auxilary fans in the back of the case.
None of this may apply to the Exos system however. I'm guessing that the performance that is desired is just to lower temps, and that fan noise is not an issue. The Koolance case and Exos systems pumps have a flow rate of 2L/min, or about 32 Gal/hr. This is a fairly low flow rate compared to most water cooling pumps, however if you use waterblocks that are efficient at low flow rates like the Swiftech it's not a major issue. The Exos radiator is fairly large and thin, this works well with lower airflow rates and axial fans that can't generate a lot of pressure differential. If you measure the temp of the air going into the radiator and the temp of it coming out it will give you an idea of how much room for improvement you can get by increasing airflow.
The equation is T = 1.76*(Watts)/CFM where T is in Celsius
so for 100Watts and 40 CFM the delta T will be 4.4 degrees C. If you double the airflow to 80CFM the delta T will drop to 2.2 degrees C, thus lowering the whole water cooling system temp by 2.2 C. If you increased airflow to 160CFM you would drop temps by 3.3 degrees instead. Note that if you can drop the air temperature going into the radiator by 3.3C (by keeping it away from hot air exhaust say) you get the same benefit as Quadrupling the airflow.
More powerful pumps tend to benefit waterblocks that have small effective heat transfer areas, where high flow rates tend to cool the block off more because only a fraction of the water flowing through the block has a chance to contact the block and pick up heat on it's way through the block. Blocks where a large portion of the water flowing through contacts the block and picks up heat (like the Swiftech 6000) work well at low flow rates and benefit little from increased flow rates. Water has a huge thermal capacity. 140Watts will only raise the water temp by 1 C at a 2 Liter/min flow rate. Higher flow rates make almost no difference in this respect, they only help some waterblocks transfer heat to the water better, if you get a block that's efficient at low flow rates a higher capacity pump will not make for much system improvement.
I'd suggest getting a thermometer and seeing where the largest temperature differentials in the system are and work on those first. My guess would be that better airflow (and making sure the incoming air is not hot) and possibly a better CPU block like the swiftech would be the cheapest and most effective improvements. I tend to dislike the Koolance systems because of the 80mm fans that make so much noise because of their RPM, but then I'm a silent type freak. Hope you find something usefull in here, or anybody else who crawls through this thread.

09-23-2004, 10:08 AM	#7
ferdb Cooling Neophyte Join Date: Sep 2004 Location: texas Posts: 68	I've had several Koolance systems and modified them for better performance and efficiency, however those were all Case versions, not Exos. The Koolance cases have a major problem with the way airflow was set up, It's very restrictive and it also sucks hot exhaust air back in through the radiator. Oddly enough the reason they set up the airflow this way was because the pair of submerged pumps they use run off AC, and they use a transistor circuit and transformer on a controller board to generate this AC from the 12Vdc line. This controller board gets HOT, so hot in fact that without substantial airflow past it the thing melts down. The airflow path in the Koolance cases is deflected and diverted with a plastic sheet so that sufficient airflow ends up flowing past the controller board mounted on the rear roof of the case. If you remove the sheet to improve the airflow you will fry the controller board if you don't provide some other means of providing airflow to it. The simplest way to do that is use a power supply with a bottom fan such as an Enermax. Flip the supply over (you may need to file the mounting bracket a bit to get it to fit) and you will now get enough airflow past the controller board to keep it from overheating. Now you can rip the Plastic airflow director sheet out and flip the fans over so they are all pulling air out of the case. This will substantially drop the temps of the water cooling system (as much as 10C or more) it also now will pull plenty of air past the harddrives to keep them cool (the Harddrive water blocks are a bad idea, I've lost several drives using them). You can now run the fans much slower and quieter and still achieve lower temps than before. Also you now have lots of airflow over the motherboard and cards where before there was almost none, unless you installed auxilary fans in the back of the case. None of this may apply to the Exos system however. I'm guessing that the performance that is desired is just to lower temps, and that fan noise is not an issue. The Koolance case and Exos systems pumps have a flow rate of 2L/min, or about 32 Gal/hr. This is a fairly low flow rate compared to most water cooling pumps, however if you use waterblocks that are efficient at low flow rates like the Swiftech it's not a major issue. The Exos radiator is fairly large and thin, this works well with lower airflow rates and axial fans that can't generate a lot of pressure differential. If you measure the temp of the air going into the radiator and the temp of it coming out it will give you an idea of how much room for improvement you can get by increasing airflow. The equation is T = 1.76*(Watts)/CFM where T is in Celsius so for 100Watts and 40 CFM the delta T will be 4.4 degrees C. If you double the airflow to 80CFM the delta T will drop to 2.2 degrees C, thus lowering the whole water cooling system temp by 2.2 C. If you increased airflow to 160CFM you would drop temps by 3.3 degrees instead. Note that if you can drop the air temperature going into the radiator by 3.3C (by keeping it away from hot air exhaust say) you get the same benefit as Quadrupling the airflow. More powerful pumps tend to benefit waterblocks that have small effective heat transfer areas, where high flow rates tend to cool the block off more because only a fraction of the water flowing through the block has a chance to contact the block and pick up heat on it's way through the block. Blocks where a large portion of the water flowing through contacts the block and picks up heat (like the Swiftech 6000) work well at low flow rates and benefit little from increased flow rates. Water has a huge thermal capacity. 140Watts will only raise the water temp by 1 C at a 2 Liter/min flow rate. Higher flow rates make almost no difference in this respect, they only help some waterblocks transfer heat to the water better, if you get a block that's efficient at low flow rates a higher capacity pump will not make for much system improvement. I'd suggest getting a thermometer and seeing where the largest temperature differentials in the system are and work on those first. My guess would be that better airflow (and making sure the incoming air is not hot) and possibly a better CPU block like the swiftech would be the cheapest and most effective improvements. I tend to dislike the Koolance systems because of the 80mm fans that make so much noise because of their RPM, but then I'm a silent type freak. Hope you find something usefull in here, or anybody else who crawls through this thread.