Cooling innova Konvekt-O-Matic radiator

I'm toying with the idea of changing to a totally passive radiator in my watercooling setup.

I'va seen Innovatek's Konvekt-o-Matic passive radiator here , but there isn't much info on it.

Does anyone have any experience of this, or any other passive rad?

Comments welcome, especially re the whole passive rad approach ......


Cheers,

Olly

 

Well, I never got around to my planned passive experiments as deep as I would have liked but it looks like a reasonable approach to the idea as far as I can make out from that photo.

Normal rads used in actively cooled (fanned) setups are generally copper cored with densely packed fins. These channel forced airflow over more effective surface area in a smaller package.
For a passive rad, you need wider radiant surface area exposed to the general surroundings, to make up for the lack of airflow (which can hit temps hard otherwise).

At a guess, they've gone for an alu option from the stance of weight consideration for the size and possibly also (and I'm going to sound controversial here, 'cos this is widely debated...) it giving up heat better. There.. I said it!
This assumption is based on the principle that Alu can hold less heat than copper before reaching it's maximum thermal capacity and presumably being forced to transfer it to the air. (I could be talking out of an alternative orifice here though, it's not something I've attempted to prove empirically either way).
I seem to remember that in the brief experiments I did conduct my copper rads stabilised at a higher temp (without fans) than a previous alu-based setup (though foggy memory and partial data loss preclude me checking all these facts for confirmation), although with fans, temps were ultimately lower with the copper rig (again, iirc).

For a given heatload, I'm guessing it obviously works or they wouldn't have brought it to market... What that heatload is though, I don't know. :shrug:

HTH.

 

I've been discussing radiators and heatercores with my gearhead uncle and his gearhead friend and their opinion is that as far as real world preformance go they would always choose aluminum radiators for their cars (aka weight is no object) they say that the higher heat dissipation properties increas the acctual preformance. I have not tested any of this but it is their opinion and they have a fair amoutn of experiance and knowledge.

 

Pug, I think you're on the right track.

This goes back to one of our discussions where I think you quickly corrected my assumption of the amount of thermal energy transferred to the air via convection vs radiation.

I believe with this radiator, radiation is obviously a much more significant mode of transfer, since convection becomes hampered by a lack of air flow.

In this case, your comment about aluminium "giving up heat" better than coper is quite correct, though not quite for the reasons you describe.

Essentially, aluminium radiates heat better than copper. That is a horrible statement coming from a scientist, but that is the basics of it. All materials are capable of radiating heat, and they are graded relative to a theoretical black body, which radiates perfectly. Aluminium is closer, in its's ability to radiate heat, to a black body than copper. So with convective heat transfer (independent of the material from which the heat is transferring) miinimised, radiation (dependent of material) becomes more significant, and in this scenario, aluminium is the better choice.

With regards to motorsport, aluminium is used primarily because of it's weight savings and lower cost, both KEY factors in the design of an automobile. Car raditors are still very reliant on airflow, hence the need to have cooling fans mounted on the radiators, which suggests that in that case, convection is still the significant mode of heat transfer.

All that said, this is still a very interesting product. I am very curious to see how it performs.

8-ball

 

Mind you, having said all of that, the name kind of implies that convection plays a big part here.

Looking closely at the image, it appears to have a similar construction to a househlod central heating radiator.

The large flat surfaces as described above by pug are intended to increase radiation, while the internal structure, with what appears to be vertical "channels" would suggest the heat from the coolant warming the air in the channels and setting up convection currents of rising air, thus providing a small amount of airflow (without the use of fans )

Still, it is not very large for a passive cooling radiator, but I do believe that it will work better passively than would a similar sized radiator of a more conventional heatercore design. I'm intrigued.

8-ball

 

Well, I'm still not totally convinced that Aluminium gives up heat better across the board, but maybe it does in a certain heat range.

There does come a point when it reaches entropy though and just isn't physically capable of transferring any more heat anyway but I'm not sure at what point that is (at this time on a Saturday night, anyway )

Interesting, just the same.


(Oh and I really don't know why I put radiant in bold... )