Pro/Forums - View Single Post - Radiator CW vs Air/Coolant Delta-T

Long Haired Git · 10-12-2005, 10:35 PM

Okay, so I'm updating my approximator with all the excellent work BillA did at Swiftnets: A manufacturer who publishes PQ and CW charts.
Woot!

Anyhooowwww, I am looking at the MCR220QP page, and there's a so-BillA-looking chart for C/W vs flow rate here:

http://www.swiftnets.com/assets/imag...cw-600x440.gif

(I'd link to the page, but witht the menu system, I can't. Oh heck, at least not properly, but here's the page using properties: http://www.swiftnets.com/products/MCR220-QP.asp

Anyway, the test says there is a kept-constant 10 degree difference between the water temp and the ambient air temp.

Now, naturally in my simulator as per real life, the more efficient a radiator is the closer to ambient the water temp runs. Its often, for the rigs I see and comment on, less than 10 degrees.

So, how linear is it? How do I approximate it? Do I bother?

Typically I don't see in my approximator the water temp getting under 2 degrees above ambient. However, I imagine at that temperature, the C/W is not going to be as good as when the delta-T is 10 degrees.

I'd love a chart showing, for just one or two setups (perhaps just vary the airflow once) showing the impact of air to coolant delta-T in the range of 2 to 20 degrees.

Heck, given all the hacks in my approximator, I'd settle for someone having an approximation of the shape of the graph.
Is it linear?
1/X?
X^2

My brain says that at a zero delta-T you'd get zero heat flow(regardless of anything else) so that's one point on the graph. The chart referenced above shows another single point on my proposed chart. The question is, does the relationship between the delta-T and the C/W continue linearly, or does it improve (so increasing the delta-T to 20 degrees does more than double the performance of the rad) or does it taper off (law of diminishing returns and all that).

My money's on the latter.

I just don't want to have my approximator mega-inaccurate as it assumes the same effectiveness at delta-T = 2 as at delta-T = 10 and delta-T = 1000 (for that matter).

10-12-2005, 10:35 PM	#1
Long Haired Git Cooling Savant Join Date: Jan 2003 Location: Sydney, Oz Posts: 336	Radiator CW vs Air/Coolant Delta-T Okay, so I'm updating my approximator with all the excellent work BillA did at Swiftnets: A manufacturer who publishes PQ and CW charts. Woot! Anyhooowwww, I am looking at the MCR220QP page, and there's a so-BillA-looking chart for C/W vs flow rate here: http://www.swiftnets.com/assets/imag...cw-600x440.gif (I'd link to the page, but witht the menu system, I can't. Oh heck, at least not properly, but here's the page using properties: http://www.swiftnets.com/products/MCR220-QP.asp Anyway, the test says there is a kept-constant 10 degree difference between the water temp and the ambient air temp. Now, naturally in my simulator as per real life, the more efficient a radiator is the closer to ambient the water temp runs. Its often, for the rigs I see and comment on, less than 10 degrees. So, how linear is it? How do I approximate it? Do I bother? Typically I don't see in my approximator the water temp getting under 2 degrees above ambient. However, I imagine at that temperature, the C/W is not going to be as good as when the delta-T is 10 degrees. I'd love a chart showing, for just one or two setups (perhaps just vary the airflow once) showing the impact of air to coolant delta-T in the range of 2 to 20 degrees. Heck, given all the hacks in my approximator, I'd settle for someone having an approximation of the shape of the graph. Is it linear? 1/X? X^2 My brain says that at a zero delta-T you'd get zero heat flow(regardless of anything else) so that's one point on the graph. The chart referenced above shows another single point on my proposed chart. The question is, does the relationship between the delta-T and the C/W continue linearly, or does it improve (so increasing the delta-T to 20 degrees does more than double the performance of the rad) or does it taper off (law of diminishing returns and all that). My money's on the latter. I just don't want to have my approximator mega-inaccurate as it assumes the same effectiveness at delta-T = 2 as at delta-T = 10 and delta-T = 1000 (for that matter). __________________ Long Haired Git "Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford) My Rig, in all its glory, can be seen best here AMD XP1600 @ 1530 Mhz \| Soyo Dragon + \| 256 Mb PC2700 DDRAM \| 2 x 40 Gb 7200rpm in Raid-0 \| Maze 2, eheim 1250, dual heater cores! \| Full specifications (PCDB)