Interesting Note on Bong

[Silver]

At Christmas I built an oversized water block 3.5"x4" for my ak31 and used 3 3/8 inlets and 3 3/8 outlets on the block. Water flow (of course) increased dramatically. I opened up all of the holes on my spray head. The spray is very good. Pump is a 500 GPH Danner. I have been using a 80 mm fan at 12v to move air in the bong but have been losing a lot of water. Two days ago I changed it to 5v but found that the water temp would then exceed ambient. Placing my hand over the fan I felt back pressure and over the bong exit no (or very little) air flow. Today I disconnected the fan altogether and have a good air flow out of the fan entrance and the water temp has once again fallen below ambient. It appears that with the increase in water volume the spray is causing an air flow into the bong (from the exit) and the air is now exiting (with some force) out of the where the fan is mounted. Next is to remove the fan altogether and see if this further aids airflow and thus reduces temps farther still. Kind of neat to get rid of the fan altogether while reducing temps and preserving a greater degree of water due to no sprites. Exit air is moving, warm and humid.

[FrozenInHI]

here's one you'll love, put that same fan on the top of the bong and have it blowing down into the spray! you will want to consider using a filter for it so you don't inject dust into there, but the results are pretty good, lowered my water temps about another 2 to3 c below ambient, as close to the wet bulb temp as i can get without actually reaching it yet. give it a shot and see what happens, monitor the water temp as it exits the bong, you should see a bit of difference.

[GoldenTiger]

NM... I was correct already.

[Silver]

Will give it a go.

[GoldenTiger]

Can you explain how the heck a fanless bong works?? It's totally going by me for some reason :confused:.

[Silver]

This I am not sure I can tell you. I can tell you this, with 3x3/8 lines in and 3x3/8 lines out the increase in volume to the head is substantial. Due to this a good portion of my vertical 4 inch bong tube has a strong spray in it. Obviously this volume of water has to displace something and that is air. Where the y connector is for the fan there is a definate and constant air flow. This is quite readily felt with your hand. Heck it readily blows a kleenex around. The energy of course is supplied by the pump that moves the water. The air flow is enough that a 80 mm at 5v could not overcome it and therefore the two cancelled each other out and the temps rose due to vertually no air movement. At 12v the fan would overcome the resistance and I would have sprites coming out the top. Now I am not going to say that no fan cools as well as a 12v fan but it does cool well enough to run my system at 2.26v at 11x155 on a T-bird 1.4. Anyone with a good waterflow on a 4 inch pipe should be able to verify this as my setup is nothing special other than the homemade water block.

The logic behind the cooling would be the same. Airflow over the water creates evaporative cooling. Rather than a fan blowing the water against the water flow the water itself pulls in the fresh air supply.

[GoldenTiger]

Thanks :).