Optimized Level of the Pump....

Jump to latest Follow Reply
peachy

peachy

0
Feb 19, 2012
78
So I was reading the installation instruction of the Pentair Intellipro 011018 and it indicated that it should not be installed in excess of 3' BELOW water level and 8' ABOVE. This got me thinking why this is so? and what would be the PERFECT MOST OPTIMIZED position of the pump in relation to the water level? We're just about to build it so we can position it at almost any height within the recommended level.

I'm also wondering why they would give 8' on the above and only 3' below.... at 8' wouldn't that work the pump to bring the water up to that level? while if you bring it lower there's that natural movement of water to level itself so your pump is being helped by this naturally. obviously I'm not understanding something and would appreciate if someone can explain why. just very curious.... theories please.
 
They are guidelines. More realistic, I would not put an IG pool pump much more than about 3' above the water line and the perfect spot would be for the water level in the pool to be about 1/2 way up on the pump basket.

Pumps like to push water but they don't like to "pull" water...hence my suggestion of not 3' higher

If your pump is below the water line, the pump basket will flow each time your remove the lid.
 
I've had two pools going back to before I was born and the pump was about 18" below water level on both. I think it's perfect for cleaning the basket. Just let it flow--throw the heavy crud out of the basket and then the overflow cleans more crud out. Dunk the basket up and down quickly and the stuff stuck in the holes gets cleaned out. Close the lid. The amount of water lost is minor. I'm so fast at it that it takes less than a minute.

If I need to close both ends it's MP to Closed and one Jandy on the input--15 seconds max. Priming is a non-issue. And at that level, when I drop below skimmer to winterize, returns drain back toward the pool.

I wouldn't have it any other way.
 
my original inquiry though is not on convenience of maintenance but on optimized level for efficiency's sake. the pool designer originally had it 8' below water level and that was not allowed as per the installation manual.

btw, what's that "Jandy on the input" mean? Jandy check valve? you guys install check valves AFTER the filter?
 

Enjoying this content?

Support TFP with a donation.

Give Support
Likely means a Jandy 2 or 3 way valve on the suction side that can be used to close the suction line ... never want that done with the pump on.

Also many people put check valves after the filter if they have solar systems to prevent water flowing backward through the first when the solar drains.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
Just to clarify but like what you posted in the beginning.... that pumps like to push instead of pull water out. so if you have it 2' above WL wouldn't it be more work than having the basket right on WL? more work would mean less efficient. that's what i mean by efficiency.... not adding unnecessary work just by the positioning of the pump.
 
Pump above water level, The extra work the pump does by pulling the water up is pretty much offset by gravity helping to push the water down of the pressure side.

Same thing if the pump is below water level. The extra work to push the water up to the pool level is offset by gravity helping to supply the pump on the suction side.
 
Forgive me but I am bit anal about this particular point. Pumps do not "pull" water nor can they pull water and in fact nothing can pull water. There is very little tensile strength to water.

Water is actually pushed into the suction side of a pump. A centrifugal pump throws water outward through the inside of an impeller. Since water cannot be compressed or expanded, this action creates a partial vacuum in the pump chamber which is at a lower pressure than atmosphere. It is this pressure difference that pushes the water toward the pump.

Also, although there is no difference in the total head loss and efficiency the pump experiences with different pump heights, as the pump height increases, the suction head increases which in turn increases the likelihood that a pump will experience air leaks and even cavitation at the extremes. So you are just asking for problems with high installations although sometimes it can't be avoided.
 
i agree with your explanation mas.... totally get it. i'm sure it's just easier to say PULL instead of saying "the partial vacuum by the negative pressure...." :D

so mas, where would you locate the pump? right on WL? I'm not saying i'm doing mine above.... was just saying for the sake of a discussion.
 
I kind of like the idea of a self filling pump basket so at the water line would be my suggestion. I am not a big fan of having any more valves than necessary so try to avoid below the water line as well as very high above the water line where priming valves might be necessary and causes issues I noted before.
 
My pool contractor wants to locate the filter below water level (WL). He said this would prevent having to purge the air that would go inside the filter every time the pump stops. His design also shows that the vertical pipe from the pump does not extend pass the WL for the same reason. so basically the whole system is below WL. although this kinda makes sense that no air will accumulate if everything is below WL, most equipment set-ups are actually above an in-ground pool. how is this prevented—through the use of check valves? will air really enter the filter and pipes when the pump stops running? wouldn't the check valve stop the water from "draining" out of the filter?
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply