Max efficiency of heatercore at 1.5 gpm?

[bigben2k]

Following this thread, Bill just pointed out (again) that: "those rads that I have tested show a C/W 'peak' (a minima actually) at 1 to 1.5 gpm"

Here we shall talk about the possibilities of "why?".

{edit: corrected, and here I thought this was something new }

[bigben2k]

Here's BillA's test result:

...'reality' (in the form of un-accounted for influences) often skews the results



can you describe what is occuring here ? (pop quiz, lol)
note that max efficiency is unique for each rad

... the readings are at the inlet and outlet, any such is included (as is the effect of the pressure drop - several threads on this)

[Since87]

Originally posted by bigben2k
Following this thread, Bill just announced that...

Just announced?

How long have those curves been available?

[BillA]

godamn Null-A Ben, quote me correctly

1.5 or less, unique to each rad



and this is a 'correct' response curve



have fun guys

[bigben2k]

For the purposes of the discussion, here's a [rip] pic of the rads in question:


"Rad A" is the BeCooling 5 x 5 (not 5 x 10)
-Opening (Area): 5 x 5 in. = (25 sq.in.)
-Thickness (Volume): 3/4 in. = (18.8 cu.in.)
-Internal capacity (liquid volume): 72 ml
-Connections: 3/8 in. barbed hose connectors
-Tube: 4 parallel 3/8 in. copper tubes in series, on 1 1/4 in. centers
-Fins: crimped on corrugated aluminum fins, 16 per in.
-Outside Dimensions: 5 x 6 1/2 x 1 3/8 in. (w/connections)

"Rad C" is the DangerDen cube
Opening (Area): 4 1/4 x 3 7/8 in. = (16.5 sq.in.)
Thickness (Volume): 4 1/2 in = (74.1 cu.in.)
Internal capacity (liquid volume): 172 ml
Connections: 1/4 in. CTS straight tube
Tube: 15 offset parallel 1/4 in. copper tubes in series, on 1 in. centers
Fins: crimped on flat aluminum fins, 8 per in.
Outside Dimensions: 6 3/4 x 4 3/4 x 5 in. (w/connections)
Factory fan mounting: Panaflo FBH-12G12L (67 cfm "rating"), to be added shortly


From Bill's original article, here

[BillA]

Null-A Ben
daily you earn your handle (but you mean well, I accept that)

no, 5x10 means 5x10, this rad was not in the original article
but I later tested it and it was/is SO GOOD that I made a graph for it

just double the finned area and volume

so what makes this rad perform so well ?

[bigben2k]

I've been staring at them too long, lol!

Some observations:

-the convected heat exits the BeCooling unit, instead of being allowed to raise the ambient air temp, for the subsequent passes past the first row of tubes in the DangerDen cube. That's probably the most important difference, IMO.

-The tubing in both designs is of copper. the fins are crimped aluminium.

-The BeCooling 5x10's fins are corrugated, where the DD cube's fins are flat, but that should have little influence, in favor of the 5x10 (IMO).

-The fin density is 16 per inch on the 5x10, where it's 8 per inch on the cube. This is probably a significant factor (IMO), but can't single-handedly explain the performance gap. I always thought that a fin-to-gap ratio between 1:5 and 1:8 was ideal for air convection. What's the fin thickness?

-Tubing in the DD cube is 1/4", the BeCooling unit's is 3/8", so the flow velocity should be higher in the DD cube, which should be favorable to cooling, despite the pressure drop.

[BillA]

dig deeper

[bigben2k]

I was going to mention the fact that the fins are continous throughout, in both designs, but I'm not completely sure what to make of it.

You mention a 1 1/4 center on the 5x10, and a 1" center on the cube. I understand the meaning: 1" from center of tube, to the center of the next tube.

What puzzles me is why these fins would be continous throughout the whole cube (if in fact they are): wouldn't that limit the dispersion of the heat from the tubes?

By extension, wouldn't the 5x10 benefit from a saw cut into the fins, between the tubes?

[BillA]

something else completely
google transmission coolers
look for that unit
(or read Be Cooling's description ? - I think its mentioned)

[Alchemy]

Jules: What does the Becooling unit look like?

Brett: What?

Jules: [pointing his gun] Say "what" again. SAY "WHAT" AGAIN! I dare you, I double dare you, motherf*****! Say "what" one more godd*** time!

Brett: Instead of being allowed to raise the ambient air temp, for the subsequent passes past the first row of tubes in the DangerDen cube.

Jules: Go on.

Brett: The BeCooling 5x10's fins are corrugated. . .

Jules: Does it look like a bitch?

Brett: What?

[Jules shoots Brett in shoulder]

Jules: DOES IT LOOK LIKE A BITCH?

[BillA]

lol
this is why Cathar posted that picture of me (sic)

[bigben2k]

I'll have to put off googling right now, but I'll post the BeCooling description, if someone else wants to take a shot at it ('til I get back):

A full 12.5" by 5" radiator. Fits 2 120mm fans. This has about 150 cooling fins! Cools ALOT better than a comparable sized Perma-Cool found at other shops. Higher fin density, better tube to fin contact. 3/8" barb fittings.

The smaller unit has this description:

6.25"x5"dimension. Perfect size for mounting inside a case with a 120mm or 5" box fan. Unit has 600 square inches of optimal heat exchanging fin and copper tubing. Performs better than other similar sized tube and fin radiators. Water channel is copper pipe. Fins are aluminum.

[BillA]

my error, thought it was in there
google transmission coolers, find that unit - see what is said about it

[bigben2k]

I think I got it...

The Ultra-Cool® transmission oil cooler is an effective and economical way to keep the transmission at its optimum operating temperature. High efficiency turbulators in each tube direct the fluid for superior heat transfer.

From the Hayden website.

Am I close?

[BillA]

yup, give that man a chocolate cigar
turbulators are GREAT devices
displace fluid in the center
increase velocity AND mixing at the tube face

[bigben2k]

Yeah, yeah, yeah...

Here's a page of the different turbulators.

We've been over this before, I guess it just didn't make sense to me, at the time.:shrug:

[Blackeagle]

BillA,

Any chance you'd have time to post up the results on Sense87's rad and mine for comparison with these (or any others you'd like to include or prefer) ?

If the data on those is posted on a differant thread could someone provide a link, I may have missed it.

[Blackeagle]

Just read the page you posted on those turbulators Ben, very interesting.

So just how well do the better heater cores compare with these trans coolers with turbulators?

I've never really spent much time looking over the trans coolers as so many people recomend the heater cores as the best way to go.

[bigben2k]

You still can't beat a heatercore: it's the best.

In fact, it beats the Serck rad (a corrected graph was posted for it, but no corrected graph for the whole lot).

HCs even run with a lower pressure drop than anything else, except the Serck.

[hara]

Originally posted by bigben2k
You still can't beat a heatercore: it's the best.

In fact, it beats the Serck rad (a corrected graph was posted for it, but no corrected graph for the whole lot).

HCs even run with a lower pressure drop than anything else, except the Serck.

So why all the fuss about the 10x5?

[BillA]

rad stuff from this thread

to repost:





as can be seen, at low air flow rates the dissipation will peak and then decline
this is reflected (obviously) in the C/Ws

no Null-A Ben, I do not believe that heater cores are 'the best'
but they are probably the most cost-effective

Blackeagle - your hc pressure drops are at that link

[Blackeagle]

Thanks so very much Bill. The graph is great. And adding the meat to it as you suggested will be of great interest to me, as well as a good challange.

Thank you again.

[satanicoo]

"Trans-T Turbulator

This square, rippled copper turbulator is used within 3/4" tubing for lower viscosity fluids, where fluid compatibility or minimized pressure drops are required. The Trans-T, like our SwirlFlow Turbulator, breaks up laminar flow, forcing a better mix of fluid closer to the outer tube. The resulting fluid distribution profile promotes improved heat transfer."

i guess this one looks the best turbulator.
litle pressure drop and brakes the laminar flow in low viscose liquids (like water)

where can i find such a heatercore?

[freeloadingbum]

I don't think BillA's test accurately depicts what occurs in an enclosed system.

When you increase the flow rate in an enclosed system, the input temp to the rad will decrease because more flow is absorbing the same energy from the block.

In BillA's test, he mantains the same input temp at all the flow rates which means he's adding energy when he increases the flow rate. It takes twice as many watts to maintain a 5C delta at twice the flow rate, not counting the increase in pump energy.