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dual heatercores a good idea?

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rxtrom

Member
Joined
Oct 14, 2003
Location
Philadelphia
Hey guys, got yet another Q for you, i have been doing some searching, but have not come to a conclusion yet about it. I want better temps than my 39C load. So i was thinking about getting another rad/heatercore. My system would go like this

Pump -> RES-> HC-> HC-> CPU - > Pump

I was also thinking about useing the 2 HC's as one and getting Y adapters

Y adapter -> HC HC-> Y adapter

AND

FAN-> SHROUD-> HC -> (siliconed) HC-> shroud ->FAN
because i do not have the room to mount them seperatly

LMK your thoughts thanks ROB
(probably going to get a WB for the 9700 pro soon too)
 

Korndog

Member
Joined
Nov 30, 2002
Location
California
well.. a second HC would more likly aid your system dumps more heat the the HC can handle. if that was the case, your temps would increase continiously. Since i doubt that's the problem, an extra HC may actually increase temps due to decrease in flow rate.
if you were to upgrade to a larger pump as well as a second rad, then you would get results
 

E-Licious

Member
Joined
Dec 27, 2003
rxtrom said:
I was also thinking about useing the 2 HC's as one and getting Y adapters

Y adapter -> HC HC-> Y adapter

Yes to this.


rxtrom said:
FAN-> SHROUD-> HC -> (siliconed) HC-> shroud ->FAN
because i do not have the room to mount them seperatly

Not sure how well this will work. It'd prob still be better than one heatercore though.
 

E-Licious

Member
Joined
Dec 27, 2003
Korndog said:
well.. a second HC would more likly aid your system dumps more heat the the HC can handle. if that was the case, your temps would increase continiously.

Huh?

Korndog said:
Since i doubt that's the problem, an extra HC may actually increase temps due to decrease in flow rate.

Not if he puts them in parallel. That would increase flow rate.
 

slater3333uk

Member
Joined
Dec 8, 2002
Location
Suffolk, UK
I think you would be better off with

Res -> Pump -> CPU -> HC -> HC -> Res

You want the pump drawing directly from the res and straight into the cpu block right?

i would recormend against it as the decrese in flow rate will attuay cause a rise in temps. Dual rads will only be any good in a system that has a high heat load on it eg. peltiers or dual cpus.
 

Korndog

Member
Joined
Nov 30, 2002
Location
California
E-Licious said:

Not if he puts them in parallel. That would increase flow rate.

adding stuff to your system, regardless of how its added, will decrease flowrate.

E-Licious said:

heater core removes heat, obviously. if can't remove all the heat dumped into the water by componants by the first cycle, then obviously the Heatercore is inefficiant for the amount of wattage your system produces. If your Heatercore can remove the the heat from you water efficiantly a larger or a second heatercore will not remove more heat then the first.
 

Korndog

Member
Joined
Nov 30, 2002
Location
California
rxtrom said:
i have a maxijet 1200 295GPH, what would be an upgrade from this?
you may want to consider a danner mag for an upgrade
the maxijet has a 69" max head
the mag 3 has a 126" max head
so although the mag 3 is only 350gph, which isn't much of an increase in max flow, the head is almost double which means with pressure it'll outpreform the maxi by a large margin.
just for example, the maxi jet would probably get like 60-80gph with two heatercores, two waterblocks, and 4 feet of tubing. if u replaced it with a danner mag drive 3, you would be getting about 200gph in the same system. Even upgrading to a danner mag 3 without adding a HC will improve your temps, expectually if you have a block that benefits from it like the WW, cascade, or RBX.
 

E-Licious

Member
Joined
Dec 27, 2003
Korndog said:


adding stuff to your system, regardless of how its added, will decrease flowrate.

Incorrect. When you have two things in series, the total resistance is greater than either one. When you run two things in parallel, the total resistance is less than the resistance of either one. The exact equations for 2 resistances in an electrical circuit are:

Series: R1 + R2 = Rtotal

Parallel: (R1*R2)/(R1+R2) = Rtotal

Do the math and you'll see that the total resistance is way lower in the parallel case. I'm sure that the equations for a fluid system are equivalent to these. Lowering the total resistance will increase flow rate for the system.

But, I wouldn't advise running anything in parallel with the CPU block. You get more flow in the system, but you get less flow in each individual branch. Think of it this way, if total flow in the system is 1 GPM, you can't have more than 1 GPM in either of the branches, unless one branch has negative flow rate (going the other direction). So, since you want as much water going through the CPU block as possible, I wouldn't put anything in parallel with the CPU block. Some do, but I wouldn't.

Another advantage of running two rads in parallel is that both rads are getting the hottest water in the system. We know that heat dissapation is fastest when the delta T is highest, so you want the hottest water to be going through both rads.



Korndog said:

heater core removes heat, obviously. if can't remove all the heat dumped into the water by componants by the first cycle, then obviously the Heatercore is inefficiant for the amount of wattage your system produces. If your Heatercore can remove the the heat from you water efficiantly a larger or a second heatercore will not remove more heat then the first.

This is true if the water temp at the outlet of a single radiator is the same as the air temp. However, this is hardly ever the case. The lower the delta T, the slower the heat dissapation. Need I explain more?
 

E-Licious

Member
Joined
Dec 27, 2003
Korndog said:
just for example, the maxi jet would probably get like 60-80gph with two heatercores, two waterblocks, and 4 feet of tubing. if u replaced it with a danner mag drive 3, you would be getting about 200gph in the same system.

Can you please show how you are getting these values?
 

Korndog

Member
Joined
Nov 30, 2002
Location
California
Cyrix_2k said:
I'd say a Hydor L30 or an ehiem 1250 would be an upgrade.

BTW, I agree with e-licious.

eheim has a 79" head and hydor has 75"
not much of an upgrade, although these pumps are better quality then the maxijet. i would still go with the danner mag 3
 

FIZZ3

Member
Joined
Jun 27, 2002
Location
NL, Europe
I'd prefer a kingsize heatercore over a messy dual setup if I wanted increased cooling capability from my system. Less messy, less restriction, less unneeded loop length.

You can only go so far with watercooling though, keep that in mind. 39C load is not so bad IMO (can't give detailed info here, because the temp measurement is fairly uncontrolled ;) ), and without active cooling you have a bottom of ambient plus a few degrees anyway.

Also instead of multiple fans on multiple heatercores, you might want to use stronger ones on the existing core instead. Airflow over a radiator helps a lot... but of course you'll have to face the extra noise then too.
 

Korndog

Member
Joined
Nov 30, 2002
Location
California
E-Licious said:


Can you please show how you are getting these values?
its just an example.
http://www.reefcentral.com/calc/hlc2.php

please keep in mind that i'm simply stating facts. these are not my opinions.
if u want my opinion, heatcores, expectually the large 6x7 ones, are more then enough for a cpu, gpu, NB water cooling system as long as u have adequate airflow. putting your money and effort into a stronger pump and a better waterblock would show better results.
 

Korndog

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Nov 30, 2002
Location
California
using the flow calculator set at 2ft vertical, 1ft horizontal and 3/4" tubing the Mag3 gets 321gph and the maxi gets 52gph, i guess i was too generous with my previous example.
 

E-Licious

Member
Joined
Dec 27, 2003
That's a handy calculator.

Stating facts is one thing. That's ok, but when you make an incorrect statement, I feel the need to correct it if I can.
 

Korndog

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Nov 30, 2002
Location
California
E-Licious said:
That's a handy calculator.

Stating facts is one thing. That's ok, but when you make an incorrect statement, I feel the need to correct it if I can.

of course, i know what you mean. the previous numbers were from my own old calculations (sigfiged) with elbows and y connectors included, i was probably off because i used the flow graph instead of that calculator, so i was using it as an example. no one should expect similar GPH on their system, but you get the idea.
 

E-Licious

Member
Joined
Dec 27, 2003
Korndog said:


of course, i know what you mean. the previous numbers were from my own old calculations (sigfiged) with elbows and y connectors included, i was probably off because i used the flow graph instead of that calculator, so i was using it as an example. no one should expect similar GPH on their system, but you get the idea.

I was talking about the parallel resistance
 

pelikan

Member
Joined
Jan 22, 2003
If I were you I would not be concerned with those temps. I'd be busy raising my vcore.

If you want more radiator power why not just get a hc that fits two 120's like a caprice?