Stupid pump question....

[Lineman7]

I have a 1.5hp pump for my bubblers and waterfall. Will I shorten the life of my pump if I choke it out by closing the valves going to the features? Love my bubblers and waterfall.... but sometimes it's so loud in the pool I have to really crank up my music to hear. I like the water movement though... makes the pool feel cooler when it's 106 out.

I wish I had a VSP on the features.

 

[mknauss]

You can restrict the flow out of the pump. Just be sure to not dead head it.

 

[Lineman7]

You can restrict the flow out of the pump. Just be sure to not dead head it.

Roger that. Thank you, sir.

 

[mknauss]

If you want to permanently reduce the flow and reduce your electrical cost, get a smaller impeller for the pump.

 

[arvil]

Not a problem at all. The operation of a pump seems counter-intuitive. It takes very little energy to develop pump pressure, but more energy to move the water. If you could put an ammeter on the pump, you’ll find it draws more current to move it’s capacity in gpm than at shutoff head (all valves closed, no water flow). So, if it’s moving even a little bit of water, it’ll be happy. A pool pump could run for quite some time at shutoff head before overheating the impeller and housing will occur, so, if you’re happy with main circulation and all the other stuff off, your pump will be just as happy.
Let me give you an example. I’m a volunteer firefighter and drive fire trucks, with a pump capacity up to 2,000 gpm.. When we flow water on the fireground, in order to flow more water to hoses, we have to crank up the rpm, more engine power to move more water. Most times I can’t see the fire ground, so to keep the pump from overheating if the firefighters shut off their lines, I pull the small booster line and just let it trickle maybe a couple gallons per minute to the ditch. Just that small flow through that big pump is plenty to keep it cool.

So, enjoy.

 

[Lineman7]

If you want to permanently reduce the flow and reduce your electrical cost, get a smaller impeller for the pump.

Now that is something I did not consider. Good idea. I'd be happy with a 1/4 to 1/2 reduction. Sounds like a good winter project after I shut the pool down. Thanks for the idea.

 

[Lineman7]

Not a problem at all. The operation of a pump seems counter-intuitive. It takes very little energy to develop pump pressure, but more energy to move the water. If you could put an ammeter on the pump, you’ll find it draws more current to move it’s capacity in gpm than at shutoff head (all valves closed, no water flow). So, if it’s moving even a little bit of water, it’ll be happy. A pool pump could run for quite some time at shutoff head before overheating the impeller and housing will occur, so, if you’re happy with main circulation and all the other stuff off, your pump will be just as happy.
Let me give you an example. I’m a volunteer firefighter and drive fire trucks, with a pump capacity up to 2,000 gpm.. When we flow water on the fireground, in order to flow more water to hoses, we have to crank up the rpm, more engine power to move more water. Most times I can’t see the fire ground, so to keep the pump from overheating if the firefighters shut off their lines, I pull the small booster line and just let it trickle maybe a couple gallons per minute to the ditch. Just that small flow through that big pump is plenty to keep it cool.

So, enjoy.

Good analogy. Makes sense....

I've been reluctant to close my valves more than half. But, I'll try it tonight and see how it goes.

Thanks

 

[arvil]

Wouldn’t even have to make a project of it. Just shut off or throttle down the features you want to, keep the main returns open enough to keep the pool clean.

 

[Toxophilite]

Not a problem at all. The operation of a pump seems counter-intuitive. It takes very little energy to develop pump pressure, but more energy to move the water. If you could put an ammeter on the pump, you’ll find it draws more current to move it’s capacity in gpm than at shutoff head (all valves closed, no water flow). So, if it’s moving even a little bit of water, it’ll be happy. A pool pump could run for quite some time at shutoff head before overheating the impeller and housing will occur, so, if you’re happy with main circulation and all the other stuff off, your pump will be just as happy.
Let me give you an example. I’m a volunteer firefighter and drive fire trucks, with a pump capacity up to 2,000 gpm.. When we flow water on the fireground, in order to flow more water to hoses, we have to crank up the rpm, more engine power to move more water. Most times I can’t see the fire ground, so to keep the pump from overheating if the firefighters shut off their lines, I pull the small booster line and just let it trickle maybe a couple gallons per minute to the ditch. Just that small flow through that big pump is plenty to keep it cool.

So, enjoy.

Same principle we used with the tiny centrifugal water pumps on diesel generator engines to pump its cooling water up 6 floors to radiator at top of building. In a sealed system the inlet and outlet side of the impeller are at equal pressures - spinning impeller creating the differential for fluid movement. Issue here, even though the impeller is theoretically freewheeling, would be dissipating heat over a long period of run time.