airtrap q

[g.l.amour]

when i saw hmale's setup, an old question of mine arised. if the airtrap isn't at the highest point of the setup, when u turn the pump off, shouldn't all the water that is above the airtrap, run into the airtrap. shouldn't u then be bleeding your system over and over again, every time you restart the pump?

e.a. see a simplification of my setup, when i put an airtrap, shouldn't it be outside my case above the top rad?

[Can O' Beans]

Are you asking if the water ABOVE the air tap will force it's way into the airtap & force the air back out into the system?

For most SEALED ones, no. As long as the air pocket sits above any inlet or outlet ports you should be good.

If you fill your sink with water, then submerge a shotglass UPISDEDOWN the whole time, it will be under all the water, yet still have the air trapped inside.


If thats not what you're asking, then I misunderstood the question

[g.l.amour]

u made the point there, was exactly what i was wondering. so when u fill the system u insert water until the water level in the airtrap is like u want, and voila. cool, thx al000t, i can start the next project then... now just find a way to not make it look too ghetto.

[airspirit]

My airtrap is not the highest point in my system. In fact, it is one of the lowest. Both my block and radiator are higher. I can run my system with the cap off of it without problems. As long as the inlet/outlet of the air trap is not capable of drawing in air and the system has less than 14.7 (if I remember correctly) lbs of coolant above the level of the air trap per sq. inch of surface area of the top of the coolant in your air trap, you're fine. Remember, the atmosphere pushes against the surface of the liquid at 14.7 lb/sq in. Since the surface is the only spot exposed, the only force to counterbalance that would be the weight of the coolant. It didn't make sense to me either until I got it working and proved to myself that my snorkel wouldn't become a geyser.

[hmale]

The air trap does not need to be at the highest point in the circuit. That is a common misconception.

Move forward with your project...set the air trap where you feel comfortable with it...you will have no problems.

Let us know how it turns out...mine worked out great!

Cheers

[Joe]

the radiator will be the air trap. The air trap does not NEED to be at the top of the system in a well designed setup. The setup above just screams for air to collect up top. Not to say that no air will get caught in the air catch, but not as much as will stop up in the radaitor. Turn your pump off for a few min and the air thats been churned into the water will collect and "pool" up top ( or the highest point it can get to). An air trap at the top is the BEST option, but not the only option; as hmale said, you dont NEED to put it on top. But if I designed a system it would be. Putting your radiator at the top will let a good deal of air sit there. Very few pumps have enough flow in systems to flush all the air DOWN in water and collect lower in the system.

Use the analogy as above, if you put a shot glass under water, where does the air go? the highest point it can.

Higher the better, and some radiators are better than others. the Tube/Fin kind are not that bad for being up top since there is few areas the air can get trapped in it. but heater cores and such are very bad for trapping quite a bit of air.

[hmale]

Good points from Joe. Practical experience is priceless. You now have options as to how you want to design your system.

Cheers!

[g.l.amour]

well... thx for all the input; it is gonna be a challenge doing it right with my kind of DIY skills. i understand now that it doesn't need to be at the highest spot, but i don't have a lot of choice. i've got the Addtronics 6896A. it's been tight cramming everything in without the second rad and reservoir to be. imagine the hayden rad sitting right after the front grille in the picture. the pump is on the groundplate of the case. there is no room above the PSU. the second rad is mounted above top plate. it is a hard job i imagine (no flowrates taken) for the eheim 1048 to cycle all the water in the system now.

so the long story leeds to this, as elbow fittings reduce flow alot; does a res reduce flow alot?
now what would be the least restrictive res design?
my gut instinct would tell me that in hmale's airtrap for example: u would have a flow restriction equivalent to 1 elbow fitting.

[hmale]

In my design (which is not the most efficient) I calculated 3 fittings in terms of impact to flow. I felt safe with this design as my pump is rated to overcome significant back pressure.

I went with this configuration for the sake of expediency and ease. In your design (from what you have shared so far) I would venture to guess that overcoming resistance to flow will be an issue. Bleeding the system may also be an issue. I would go with simplicity and test the system using a fill tube at first before moving forward with an air trap.

Cheers!

[g.l.amour]

the fill tube will be most practical. it will have to be outside of the case :-( . for testing it is prolly the best idea. thx for the simplicity.

[WebMasta33]

This is how I was able to get my airtrap in the optimal setup for my case...



Basically, before I had the airtrap, air just stayed in my radiator, and I could hear the sloshing of the air & water. now the inlet for the airtrap is about 1/4" lower than the outlet of the radiator, but you can't hear any air in the radiator anymore.

One thing that I learned, is that if you sit there, and pinch the tubing, and then let it go (while the pump is on), you can force more air out of your radiators faster than just letting it sit there and run.

If you can get away with it, tip your system around while it's running, see if you can get anymore air outa that rad.

[bigben2k]

FYI, I'm working on an airtrap. I'll write an article about it. Cheap, easy, with lots of options.

I'd have mentionned this in my worklog, but I don't have one yet...