The purge valve is to let any trapped air out of the line. The siphon line would have to be below the intended water line as not to take on air and break the siphon effect. I think of it as a Manuel water change in my sons ten gallon tank. When I "vacuum" the tank I create a siphon effect that allows water to run into a bucket placed on the floor. As long as the bucket is below the tank water will flow into the bucket. If you helped me raise the bucket above the water line in the tank water would flow back to the tank. Get the bucket and tank water line level in height water movement would stop as the tanks are equal. Add water to tank and water would move into bucket to equal the levels again....
plumbing a sump through the attic
- Thread starter john wright
- Start date
My A/C system is in my attic and when I looked to install an in-line humidifier into the attic system I was told by an A/C company that code does not allow a water line in the attic since it is an unheated space due to freezing. Wouldn't that be the same issue with using the attic for what ever you wanted to plumb for an aquarium?
Regarding my earlier post above-
-The purge valve in the 'siphon line' is for use during the priming of the siphon only.
-You will need a means to fill the siphon line with water and purge the air to begin with. Most pumps are far more efficient at pushing water, than trying to pull it, as water can cavitate (spontaneously boil) under vacuum.
-Anyone that has used a siphon will understand that they cannot have air in them. Why? Air is compressible. Water is incompressible (in practical terms). Siphons don't work well with air in the line.
-You could use the 2 pumps on the other 'flow lines' and plumb them with diverter valves so that they could be diverted and then used during the 'siphon line' priming step. Afterward, the flows are re-diverted back to the 2 'flow lines' lines.
-The purge valve would be closed once no more air comes out of it.
-The purge valve would likely have to be in the attic. A line from the valve output to a container, or to the outside, may be needed to prevent spills during priming.
-The 'siphon line' would flow in either direction, once primed, to allow the levels between the 2 sumps to remain constant. It's an 'equalizer'.
-Siphons can be used over great heights, once primed. The height of the attic is irrelevant, except during priming.
-Your pumps will need to be rated to push water higher than the highest point.
-As to potential heating of the water from the attic air, you may insulate the pipes with foam pipe insulation. It's cheap at HD/Lowe's. As long as there is substantial flow, heating in summer and cooling in winter will be minimal.
-JMHO
-The purge valve in the 'siphon line' is for use during the priming of the siphon only.
-You will need a means to fill the siphon line with water and purge the air to begin with. Most pumps are far more efficient at pushing water, than trying to pull it, as water can cavitate (spontaneously boil) under vacuum.
-Anyone that has used a siphon will understand that they cannot have air in them. Why? Air is compressible. Water is incompressible (in practical terms). Siphons don't work well with air in the line.
-You could use the 2 pumps on the other 'flow lines' and plumb them with diverter valves so that they could be diverted and then used during the 'siphon line' priming step. Afterward, the flows are re-diverted back to the 2 'flow lines' lines.
-The purge valve would be closed once no more air comes out of it.
-The purge valve would likely have to be in the attic. A line from the valve output to a container, or to the outside, may be needed to prevent spills during priming.
-The 'siphon line' would flow in either direction, once primed, to allow the levels between the 2 sumps to remain constant. It's an 'equalizer'.
-Siphons can be used over great heights, once primed. The height of the attic is irrelevant, except during priming.
-Your pumps will need to be rated to push water higher than the highest point.
-As to potential heating of the water from the attic air, you may insulate the pipes with foam pipe insulation. It's cheap at HD/Lowe's. As long as there is substantial flow, heating in summer and cooling in winter will be minimal.
-JMHO
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E.
Edit:
Edit:
I understand that the purge is to purge air but something would still have to start the siphon. The siphon is not the reliable answer. If you can keep a siphon going and start it up after a pwer outage then you only need one pump to pump it back to starting point of the siphon much like an hob overflow.
Was think the same thing. The siphon if not broken should continue thus meaning only one pump is required. Still undecided if this can really work. Some of my projects worked on paper but not so well when I built them. John and I were talking about building a mock up to test this theory of a siphon line...more thought and input from my fellow reefers please....
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How big is this system going to be? I don't understand why you wouldn't want the sump under the tank? Not bashing just wanna understand
I agree that in theory only one pump is required, and considered it. However, you will find that over distance, especially if pipe diameter is restricted (1/2 or 3/4 inch) that loss due to boundary layer effects will mount significantly as distance increases. So, my recommendation to use 2 pumps instead, one for each direction. Also, 2 pumps will allow greater flow between sumps. The siphon line is for equalization only. Much more dependable/reliable, IMO.
FWIW- the siphon should never break, once established. As long as both ends of the siphon pipe are held below water level continuously.
-JMHO
FWIW- the siphon should never break, once established. As long as both ends of the siphon pipe are held below water level continuously.
-JMHO
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What happens if one pump shuts down? How do you size the siphon to accommodate for twice the flow if one should shut down?
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The static head loss would be minimized by going with 1.5" pipe for the supply line.
For example a blueline HD with a 40' vertical run and 3/4" pipe would experience around 23.5' of head loss with typical fittings. In the same scenario except using 1.5" pipe it would only experience 2.7' of head loss. I would thinl larger pipe would be cheaper than running 2 pumps.
For example a blueline HD with a 40' vertical run and 3/4" pipe would experience around 23.5' of head loss with typical fittings. In the same scenario except using 1.5" pipe it would only experience 2.7' of head loss. I would thinl larger pipe would be cheaper than running 2 pumps.
You could run a much bigger pipe for the siphon, but that has it's own set of problems.
so,
He mentioned earlier that he will be using a controller, Apex etc., so I suggested float switches on both ends for failure intervention (stops both pumps) and alarming functions.
Also, high head pumps (~12-15 foot of head rating min.) could be plumbed so as to provide the priming flow into the 'siphon pipe' at start-up, then diverted with valves back to the 'flow pipes 1 &2' after for continuous use during operation.
so,
He mentioned earlier that he will be using a controller, Apex etc., so I suggested float switches on both ends for failure intervention (stops both pumps) and alarming functions.
Also, high head pumps (~12-15 foot of head rating min.) could be plumbed so as to provide the priming flow into the 'siphon pipe' at start-up, then diverted with valves back to the 'flow pipes 1 &2' after for continuous use during operation.
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I agree that a siphon is dependable IF it is never lost.</em> The problem I see is the siphon reacting quick enough to overcome the variations in flow.
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I've been thinking on this and I think Ichthyoid may be on to something with the siphon tube. As he stated if the pipe were equally submerged and on the same level at each tank then it would adjust. Barring a leak of a drop in water level below the pipe in the siphon there really is no way for it to loose the siphon. Now Ichthyoid since you started this you have to help determine the sizes of pipe needed
http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml">http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml</a>
I think 1/2 to 3/4....based on atmospheric pressure at 14.69
[IMG]http://en.m.wikipedia.org/wiki/Atmospheric_pressure">http://en.m.wikipedia.org/wiki/Atmospheric_pressure</a>
Thanks for the imput guys on this project. Any more thoughts....
I think 1/2 to 3/4....based on atmospheric pressure at 14.69
[IMG]http://en.m.wikipedia.org/wiki/Atmospheric_pressure">http://en.m.wikipedia.org/wiki/Atmospheric_pressure</a>
Thanks for the imput guys on this project. Any more thoughts....
-I would use the smallest diameter pipe that will get the job done. Why?
-The volume of water in the pipe will have to go somewhere when pumps stop, and/or the siphon breaks. So plan sump volume accordingly.
(I mentioned above that large pipes have their own challenges)
-Pipe volume can be calculated-
volume = pi x r^2 x L, where
pi = 3.14
r^2 = pipe radius squared (example: for 1/2 inch pipe, r^2 = 0.25 x 0.25)
L = length of the pipe run in inches (multiply feet by 12)
So, if pipe radius and length are both in inches then-
Divide the number you get by 231. That will give total gallons of extra capacity needed in sumps.
According to your first link, 1/2 inch pipe will flow 7gpm or 420 gph. That should work fine for the 'pump pipes'. A smaller (maybe 1/4 inch) pipe will work for the 'siphon pipe', as it only transfers any imbalance in flows.
These should get you what you want, while minimizing the increase in sump volumes. If you would like to talk this over, shoot me a PM and I will return my #. Please post a build thread, should you try this. Thx
PS- Don't forget the float switches in the sumps, connected to your system controller, to prevent overflow should 1 pump fail, or the siphon break. Those can save a marriage, large amount of damage and heartache!
-The volume of water in the pipe will have to go somewhere when pumps stop, and/or the siphon breaks. So plan sump volume accordingly.
(I mentioned above that large pipes have their own challenges)
-Pipe volume can be calculated-
volume = pi x r^2 x L, where
pi = 3.14
r^2 = pipe radius squared (example: for 1/2 inch pipe, r^2 = 0.25 x 0.25)
L = length of the pipe run in inches (multiply feet by 12)
So, if pipe radius and length are both in inches then-
Divide the number you get by 231. That will give total gallons of extra capacity needed in sumps.
According to your first link, 1/2 inch pipe will flow 7gpm or 420 gph. That should work fine for the 'pump pipes'. A smaller (maybe 1/4 inch) pipe will work for the 'siphon pipe', as it only transfers any imbalance in flows.
These should get you what you want, while minimizing the increase in sump volumes. If you would like to talk this over, shoot me a PM and I will return my #. Please post a build thread, should you try this. Thx
PS- Don't forget the float switches in the sumps, connected to your system controller, to prevent overflow should 1 pump fail, or the siphon break. Those can save a marriage, large amount of damage and heartache!
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