Originally Posted by skmanu
Thanks for your time and the clarity of your explaination.
The pump I am looking at is 40W external, which means, I believe, that some of the heat will be dissipated in the air and not in the res (correct me if I am wrong).
The one I use now is 20W, but inside the res.
I guess the gain would be important: 2.5xflow and 60 cms extra water height...
I was also thinking moving the rad horizontally at the same height as the pump (to reduce height of water to move), as the case would be ventilated more or less the same way. Do you think that would help?
If it makes 40, it surely does not mean it puts 40 out to the water, like you said a big chunk of that is going to be air dissapaited locally around the pump, tossing some sort of ventalation around the pump will help that... gotta figure its 40, so if you can get 30 out in the air around the pump, then you only have 10 going into the water, which is great. The hotter the pump gets during the duty cycle, the more the water it is in contact with will draw the heat into it through exchange. So when cold, it puts not all that much into the water, but once the pump gets temp/heat soaks, the more will hit the water.
I want to say I read somewhere as to a fish tank pump that was popular for a short amount of time, that started killing fish as the pump heated up, it raised the temps of the water, and thus, the fish could no longer tolerate the added heat.
Do you have a flow meter? I wonder what your inlet/outlet rad psi's are right now... I suspect its a pretty mean hit in the rad, not sure, but the rad is probably rated for a good deal of bar, but your blocks may not be, probably want to check that as you go up in pressure.
So flows, but also temps, water temp going in and water temp coming out, would tell us a lot about the exchange power of the rad.
Could always guestimate it, you know the pump pressure, so connect the rad, and have have the outlet of the rad dump into a graduated (marked) container and time it. Its a cheap and dirty way to figure it, atleast enough to compare pump power to a flow per minute.
Probably rig something up similar, fill the thing with heated water (something known), fit a thermometer to it, and rig some fans to it, and graph how long it takes to cool the water off. Try a couple different fan configs, and before too long some sorta picture should form as to the best way to rig it.
Not sure if orientation will make that much difference once you pressurize it with some flow, pressure should be felt the same in every direction once its bled, again one of the advantages in high psi systems with rounded tubing, it bears the pressure equally rather than concentrating forces in the material.
Could always pelt the thing?