Hello,
I run two return pumps on my 240 as we speak. This really gives me way more options than just one return pump. The most important is, if one fails the other is still going. The second is, I don’t have to run my dc pumps full blast. I can run them between 20-30%, which in theory makes them last longer and doesn’t drive them as hard. Third, it really equals the flow out in the dual overflows. As you are aware the piping on one side will be much longer, hence longer for water to flow and will reduce the flow as well. Because my pumps are dc, I can run the pump furthest away at 30-40% to get perfect flow. My close pump I can run at 20%, and the flow equals the other pump. In order to do this correctly lol we rely on the lovely math.
First off we need to know if your flow pipes are the same diameter from point a to b, if so that saves us a step.’since we all know fluid is not able to be compressed, (aka if you take a gallon of juice, you can change the shape of it, but you can’t put a gallon of juice in a half gallon container and still fit all the juice in. So with that said we use the simple formula of Q=V/T or q is volume flow rate and v equals volume and T equals time.
Now, there is also a secondary method that is sometimes easier which is Q=V/T=AD/T=A(D/T) or A times D/T which is hard to write on here. This is where if you know the cross section of said piping which is A then of course D would be the width of that portion of fluid.
Because now we can replace D/T with this new formula it will look like this which is Q=Av.
But the term d/t is just the length of the volume of fluid divided by the time it took the fluid to flow through its length, which is just the speed of the fluid. So we can replace d/t with v (lower case v only don’t get them confused), and it gives us the easier equation of Q=Av.
A is the cross sectional area of a section of the pipe, and v is the speed of the fluid in that section. So, we get a new formula for the volume flow rate Q=Av which that is often more useful than the original definition of volume flow rate because the area is easy to determine. Most pipes are cylindrical—which means the area can be found with A=πr^2 and the speed v of the fluid is a quantity that is of particular interest in many situations. It’s important to know that the capital V stands for volume, and the lower case v stands for speed. As I’m trying to keep this simple lol remember with waterif it flows through a pipe that is small, then large, then small or whatever you have, water can not compress, so regardless the water must speed up or slow down. If you flow through one section of pipe is say 2m^3 then all of it must be 2m^3 Or, it’s based on the equation of
Q1=Q2 then substitute the formula of Q=V/T which lol sorry breaks to V1/t1=V2/t/2 then gives us or Q= Av and then makes it simpler by giving us A1v1=A2v2.
which tada is the equation of continuity for fluids such as water.
Now lol if I have lost the poor op yet if you take the numbers off of whatever return pump you want and know your piping you can literally see the mathematical numbers and difference in flow between one or two pumps and see if it’s worth it to you. The math looks hard on this l, but If you write it out on paper it’s jusr simple fluid dynamics. I hope this helps you figure out what you Shoukd do.
Sincerely
Sarah
