Dual radiators galore

[Top Hat Theater]

I did a search on running two radiators and came to the conclusion that some people swear by running them in parallel while others swear by serial. Anyway, does anyone have any real world experience or thermodynamic calculations supporting one or the other?

I'm thinking of running two Black Ice Pro radiators using my Eheim 1250 pump and 1/2" tubing. Will the pump be strong enough to support this setup?

~THT

 

[I.M.O.G.]

the only differences that i can see are these:

1) in parallel the water is reaching both radiators at a maximum temperature; in serial, the second radiator is getting water that has already been cooled once. Of course the temperature difference is in the decimals, but that is a small difference i can see.

2) in series you do not have the restriction from splitters. this is also another minimal difference, but the turbulence of splitting the water, even if you keep your internal diameters equal, will add restriction by some amount.

3) if you dont use the same exact heatercores, then in a parrallel setup the water will tend towards the heatercore with the least resistance and your flow rate will be slightly higher than in series, and in series the most resistant heatercore will limit your total flow rate.

All of these probably count for squat in real world results, either way you put them you still have relatively equal flow restriction. Some hold the misconception that there is less resistance in parallel, but that isnt the case.

good luck.

 

[Top Hat Theater]

Here's a sticky question: will I see a temperature drop by adding the second radiator considering my current setup? My current temps at ~1.88 VCore are 42C idle, 46C load. I'm currently setup with a DangerDen Maze 3, 1/2" Masterkleer tubing, a Black Ice Pro radiator and an Eheim 1250 pump. Or would I see a more substantial drop switching blocks to a Evolution or a WhiteWater?

~THT

 

[candy7man24]

I just finished taking a physics class in school (some in thermodynamics) and basic answer would radiators on parallel would yield better results. Basically this is because things tend to cool down in a logarithmic form. The bigger the difference in temperature between two items, the more heat will transfer from the hotter item to the colder (well also depends on their ability to release/accept heat but if we are talking about water and copper/aluminum this holds), yielding more efficient cooling. When using two radiators in parallel both radiators are getting the water at its hottest point, thus they are both going to equally cool down the water. But if you have them in serial then the second radiator will get cooler water from the first one and thus not do a great job at cooling. Lastly I believe since the flow rate is reduce by half on each radiator (in parallel) the water will travel slower in each one thus having more time to cool down. Just my 2 cents.

 

[Top Hat Theater]

I thought I wanted to maintain a high flowrate at all times. Wouldn't it slowing down in the radiators slow it down through the system as a whole?

~THT

 

[candy7man24]

I thought I wanted to maintain a high flowrate at all times. Wouldn't it slowing down in the radiators slow it down through the system as a whole?

~THT

No this would not slow down the flow rate one bit, it would be the same. Assuming that the tubes are of the same diameter, if the same amount of water flow exits on end, and the same amount will enter the other end, the same flowrate is found. Some pressure is lost when splitting the water into two but the same pressure is rejain when rejoining it since the area of reantry is equal to the area of exit. This is all assuming you are using the same tubing all around. Lastly the water leaves and exits the two point in the same amount of time.

All this does not apply if you are not using the same radiators in paralllel, if you are using different radiators things are a little bit more complicated.

 

[Top Hat Theater]

Okay, thanks!

So is my Eheim 1250 strong enough to do the job? Or would I be better off switching waterblocks to a White Water or Evolution?

~THT

 

[I.M.O.G.]

Lastly I believe since the flow rate is reduce by half on each radiator (in parallel) the water will travel slower in each one thus having more time to cool down.

flow rate is decreased due to lower volume, not any change in speed. the speed with which the water moves in any tube in your system will be the same as long as resistance is the same along split lines, the flow rate only changes because less volume is moving at that speed.

THT, you could probably take a vote on this and get some different answers, but i would think the best increase in potential for your system would come from getting an evo or a white water.

pump good enough? i would also say that, yes, the eheim 1250 would be sufficient. a higher power pump doesnt hurt matters (unless you get big enough to have the heat the motor creates become considerable), but with a pump of that caliber i would upgrade elsewhere first, then later consider upgrading the pump to see if there is more potential to utilize. (i always look at a pump increase as just squeezing more out of what you have, other upgrades to your loop actually increase potential.)

better temps with another heatercore? I would expect better temps with another heatercore, but its hard to say by how much, which is what really matters. there is plenty of room for improvement in your temps relative to room temperature, but it depends where the limiting factor is in your setup. where would you guess it is? i would guess the biggest factor would be the waterblock, then the heatercore second, then the pump.

 

[SkiFletch]

yes a 1250 is more than sufficient. I too think the best solution is to get a whitewater for you. I too run a high-voltage system and believe my not the coolest temps are the result of the waterblock rather than the radiator. My reasoning for this is temps measured via my digidoc 5. My waterblock temp is significantly higher than my radiator temp. this leads me to believe that my radiator is doing its job to dissipate the heat transferred via the waterblock, but the waterblock cant quite dissipate enough heat to keep the core significantly cool at the high voltage I run.

that being said, my next upgrade is not going to be a second radiator, but rather some method of improving heat exchange at the core. possibly a TEC or a new wb. too bad the core of these damned Athlons are soo small

 

[Top Hat Theater]

I too think that my heat exchange bottleneck is the waterblock. I'll upgrade that first then if necessary, I'll put in a second raddy. Thanks for all the input

~THT