space is the bugger
not gonna get 2 fan performance from a 1 fan rad
(and push-pull is for fools)

Swiftech does sell such, though for 3/8" ID systems
http://www.swiftnets.com/store/produ...asp?ProdID=175
$45 including everything (except fans), 0.204 system C/W with Swiftech pump/res/fans

no, its the bling bling that sells the DIY market - performance is secondary
sorry

I'm wondering if Bill is trying to imply is that the heatercore is only as effective as how much airflow one can get through it. The current heatercores are very thick and tend to be restrictive in nature (versus airflow). An oil cooler tends to have much less finning and shallower depth (and of course less surface area), but would that additional airflow (when comparing identical setups of fans and shrouds) offset the resistance of a normal 2" thick heatercore when applied in a PC setup?

Or maybe I'm just misleading myself down a different path...

I QUITE agree with the push-pull Bill; I tested out those little shrouds sold for Black Ice Extremes a while back. I figured it would be reasonable to just use really long threaded posts so I could mount fan and shroud or just fan on either side. So I have push, pull, and push-pull results for with or without shrouds.

I couldn't even take the noise of 2 100CFM Papst fans at 12V in push-pull. I just couldn't stand to be in the room. Even at 7V (the results above) it was so much louder than a single fan that I wouldnt recommend it. For very little gain...

to those that think "Build a better mousetrap and the world will beat a path . . . "
bull shit
its the bling bling, low cost, don't believe a mfgr, blah blah
/ rant

like pushing a rope uphill
nice data pH

Ozymand
not implying anything, stated pretty clearly
yes, you understand
frontal area is FAR more significant than thickness, AND greater thickness requires a more powerful fan (= more noise)

no free lunch

All I ever wondered was why hasn't a company come along to make rads like HWlabs with the size, performance, bling, and half the cost. It's not a better mousetrap just one that's a lot cheaper.

Are you saying a BIP would perform about the same as a BIX?

why ? - volume

with a low speed fan, rather close - not worth any extra $ if noise is an issue

I am glad to see this from a reputable source. I've done a little experimenting that seemed to indicate this, but I've been doubting my interpretation. As a DIY guy, bright but untrained, and without much patience for the math, I do a lot by intuition and observation, and realize my margins of error are large. Hell, I don't even have the instruments for some measurements so I go by feel, or rig something up.

I am looking forward to seeing a new rad offering from Swiftech.

Oh, and Bill, lately I think you've been nearly clinically cynical, not grumpy. I've got no measurements to support this observation other than gut feel, and that is certainly suspect in calibration and repeatability.

Entia non sunt multiplicanda praeter necessitatem. Peritissimos semper praevidere possumus, rudi autem periculosi sunt.

vestri ile EGO mos non conflicto

So how does the 676 compare to a BIP? with a low or med speed fan.

sys C/W w/Swiftech stuff & Delta M fans:
MCR120 = 0.215 °C/W
676 = 0.204 °C/W
two MCR120s = 0.191 °C/W

Slight tangent, but still on the same topic.. started looking at heatercores and came across this monstrosity. It's an 11-3/4"x11"x3/4" transmission cooler that mounts similarly to the Swiftech 676 (except this unit being much larger in surface area).

For someone building an external cooling unit this could be an interesting part.. imagine an entire side of an enclosure with this being the most dominant feature. This, and the required ancilliary equipment (pump, reservoir, fans), could probably be crammed into a 6" wide, 13" tall, 13" deep enclosure by my best estimates. Maybe even smaller depending on the components selected. Mounted next to a window or an A/C unit, the performance of this unit could be surprising if the flow restrictions aren't horrendous.

I tried to do some experiments along those lines, fed a heatcore through my bandsaw in hopes of making two that were half as thick. Never could get 'em sealed. The fun of DIY, pain of waiting for speciality products.

Groth, have you tried a Honda heater core? Rather than one wide flat tube, they use three at any one point. Cut it into a one third piece and a two thirds piece, so you'd have two with the same surface area but one twice as thick... Perfect for this test. You'd only need to seal the top and bottom that way.

So flow rate is at least 7.5LPM, probably much more? (Asking because the thermal resistance of the block is higher at lower flow rates)

Are these Honda cores brass, copper or aluminum? Thanks.

Where Bill is getting at here is matching the PQ curve of the fan to the air-flow vs efficiency curve of a radiator.

If people looked at the thread earlier where someone asked about putting two radiators in air-flow series and I munched the math, it was pretty clear that this was a bad idea. Two radiators in air-flow series is essentially the same as a single double-thickness radiator.

The issue was that the fan was unable to sustain adequate air-flow through the thicker radiators to the point where the extra core rows weren't doing much of anything at all (in fact they were contributing almost nothing).

With a piss-weak fan (and most axial fans are piss-weak) something like a large orificed area single-row cored heater-core, or a tranmission oil style cooler, will be a better match.

2-row heater-cores are designed to typically be matched up with their blower-fans that are pushing 1+ inH2O of air-pressure, which is an easy thing to do for an automotive heater-core blower where at full chop they will easily do ~3inH2O of air-pressure at quite staggering flow rates (in comparison to similarly sized axial fans). Heater-core blowers also tend to sit somewhere where the bulk of their real noise is muffled very heavily, so they don't sound quite as annoying as they really are.

Given a certain sized orifice area and a good bit of nouse, one could easily design a more efficient solution than what we presently have, and still be using fairly quiet fans and getting very good cooling performance. Of course brute-force will always win, but we're talking quiet and efficient here.

Current heater-cores, by my estimate, are perhaps 3-4x more restrictive than what is ideal for a quiet low-pressure fan to work really well with. Ideally we want our fan to be pushing something like 75-80% of its rated air-flow, instead of the 30-40% that we see today with today's dual-row cores. Of course with a more "open" core, the efficiency for air-flow will drop away, but when air-flows are fairly low, this is less significant than one would think.

Something like a 15x15cm cored area heater-core, that was single-row (~ 1/2" to 5/8" thick), with a nice 10-15 degree angled shroud leading into the 12cm low-speed fan that is pulling, and had a fin density around 10-12FPI with ~8mm or so spacing between the tubes would likely perform quite a deal better than a BIX when matched with the same fan.

As you stick on more and more powerful fans, the BIX will come into its own over our low-speed-fan optimised core, but then you're paying for it with noise.

The lessons are there given all the testing that Bill has published in the past for those who are prepared to munch the math.

Do you mean you have one specially made for you?
I was able to talk with a guy in SouthAmerica and he has a contact manufacturer that can give him a fairly priced ones; same here in my place also.
My question is; is the pricing of HWLabs Rads with freight charges already?
If so why is it we here in my place have the same pricing when I know HWLabs have their units manufactured here, also their office is here. Maybe for equal pricing? my guess

No it wan't specially made, it was the plain brand for a specific make of car, it's a Transpro brand I think.

how much are you guys willing to shell out on something like this: http://www.geocities.com/beaukeke/Bl...blockone03.txt
that's a handmade version dual120mm rad 3rows single pass rad... custom made w/ built in shroud... i didnt mean to compete w/ black ice... as hwlabs owner is a good friend of mine ;)

lets just say i want to compete w/ your bad a$$ heatercore (hence the brute :evilaugh: 3rows single pass approach)... but sad to say production costs in small quantities are really expensive... :(

here's the backside pic of it w/ 120mm fan:
http://server6.uploadit.org/files/dulber-BlockOne.jpg

also currently in talks w/ oem rad manufacturer for some jap car companies...

Make it one row single pass and you'd get more interest from me personally

im a bit surprised... all the while I thought the bigger the better :cry: :evilaugh: :cry:

so would that be single 120mm or dual 120mm ;)

Read Cathar's post

Bathman yun kila Dulber ba is 3 pass or maybe they meant three rows ano?

Likewise. I run a fairly hefty fan on my rad, but to get even close to adequate airflow on that I'd have to run it at maximum speed (which yields 55dBA and 0.768in h2o per specs). A bit much for my ears. :p

@phaestus,

point taken... eventhough the fins are widely spaced???


j813,
3rows...

Widely spaced fins are not necessarily a good thing (probably bad) as that reduces the cooling effects. The thing is, though, that the back half gets MUCH less turbulence than the front half, so the back is just restricting airflow, not doing anything. Cathar is damned right about car blower noise though (have to shout, no motor noise, however), although that much pressure surprises me.

The heater core from a '79 Honda Civic is brass tubes with copper fins, I think, about 7"*7", and the barbs are already suited to half inch tubing. It's pretty good although expensive.