Pro/Forums - View Single Post - How do I calculate how much rad I really need

bobkoure · 10-12-2004, 12:37 PM

You're getting no answer because there isn't much in the way of public data on radiators - and you're asking basically for a general formula of C/W/(cfm airflow) / (temp delta) either per possible rad or for each possible type of rad on a C/W per frontal sq cm. (or something like that) It's pretty daunting.
All that said, 4412s at 12V should have no problem pushing air through a 2" heater core, so you could consider one of those.
Or, if you're going with a thin radiator, you can either undervolt those 4412s or go with lower powered fans - depends on how much you value your quiet - and what you might mean by the word "quiet".
I would guess that you'd be fine with a rad with frontal area of, at least, say around 250 sq cm - so you could use a BI Pro II, or a "big momma" 6"x6" heater core (which, if you couple with a coolshroud is nearly as easy to mount as a BIP II - and lots easier to locate in the lower front of a tower case). If you're OK with making your own shroud, then there are lots of other thin rads, both thin heater cores and transmission coolers, that have this frontal area.

You might have better luck first figuring out how much heat you're dumping, what you need your difference between ambient and coolant to be and asking if anyone else is cooling about the same wattage - and asking what they're using for rad and fans - and what their approx temps might be (only expect a rough guess on temps).

10-12-2004, 12:37 PM	#3
bobkoure Cooling Savant Join Date: Feb 2003 Location: USA - Boston area Posts: 798	You're getting no answer because there isn't much in the way of public data on radiators - and you're asking basically for a general formula of C/W/(cfm airflow) / (temp delta) either per possible rad or for each possible type of rad on a C/W per frontal sq cm. (or something like that) It's pretty daunting. All that said, 4412s at 12V should have no problem pushing air through a 2" heater core, so you could consider one of those. Or, if you're going with a thin radiator, you can either undervolt those 4412s or go with lower powered fans - depends on how much you value your quiet - and what you might mean by the word "quiet". I would guess that you'd be fine with a rad with frontal area of, at least, say around 250 sq cm - so you could use a BI Pro II, or a "big momma" 6"x6" heater core (which, if you couple with a coolshroud is nearly as easy to mount as a BIP II - and lots easier to locate in the lower front of a tower case). If you're OK with making your own shroud, then there are lots of other thin rads, both thin heater cores and transmission coolers, that have this frontal area. You might have better luck first figuring out how much heat you're dumping, what you need your difference between ambient and coolant to be and asking if anyone else is cooling about the same wattage - and asking what they're using for rad and fans - and what their approx temps might be (only expect a rough guess on temps).