head height?

[scooter7728]

quick head height ? if I'm coming out the water from the pump say 3 feet then to the filter and returning the water back up 2 feet into the pond is that a total of 5 feet head height or do I only measure the outgoing height. I think I'm right thinking 5 feet. thanks

 

[fishin4cars]

Head height is calculated from the Pump out put to the point where the water is released from the pipe or hose, NOT HOW FAR in the pipe it travels, Although the farther it has to travel in the pipe the less accurate the pump head can be correctly measured, some measure from the water level in the pond to the uppermost spot where the water exit's the pipe, The deeper the water in the pump sits in the more pressure it has to help push it to the impeller, However this does not change the actual flow rate it only helps the pump run a little more effeciently

 

[koiguy1969]

head height is measured from the pond waters surface to its hightest point of travel (usually filter inlet). and 10' of horizontal run is equal to 1' of vertical.

 

[scooter7728]

i should have said 3 ft deep and coming up the side back into the pond 2 ft high. I have a half in the ground half out pond.

 

[scooter7728]

so i wouldnt count the 3 feet it has to travel up to exit the pond

 

[fishin4cars]

head height is measured from the pond waters surface to its hightest point of travel (usually filter inlet). and 10' of horizontal run is equal to 1' of vertical.

That's good info to know! I have been told head height both ways, from waters surface and from the actual pump, I'm with you, I thought from water level as if the pump would turn off the water would level out there anyway.


Scooter can you post a pic so we can see what your talking about, I think I understand what your asking but not 100%.

 

[koiguy1969]

"so i wouldnt count the 3 feet it has to travel up to exit the pond?"

no you start figuring head at the waters surface...if you read a pumps head height rating and it says 12' this means the water will cease to pump at 12' of vertical above water flow. take that same 12' of hose and leave it under water and you will get the same flow as 6" of that hose out of the pump (this is assuming all the air has been evacuated from thew hose). because of equal pressure inside and outside the hose..once the water in the hose rises past the ponds surface it has to contend with gravitational pressure, resistance or "head"

 

[talal101]

This is a really useful post, I have been wondering about this for a while and now I know that proper size pump for my pond so thanks everyone.

 

[scooter7728]

i actually bought a new pump today and the diagram shows head height starts after it breaks the water surface

 

[vertigo72]

There is an excel spreadsheet on this page:
http://www.engineeringtoolbox.com/equivalent-pipe-length-method-d_804.html

That lets you calculate the pump head for your tubing/piping. Note you will have to look up the pressure loss for your pipe or tube as explained in that article.