Helping me pick a new well pump!

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I currently have a goulds 33GPM pump, 2HP goulds contant pressure controller 3 wire (BF20). This pump is not large enough for my home and my landscape. When my sprinklers change zones I have a pressure drop inside my home due to the pump not being large enough.

Pressure on system is a constant pressure pump. 68-75PSI is the range.

Things on my well pump

Geothermal- when on uses 9GPM
Home with 5 bathrooms
4000sq/ft home with sprinkers in ceiling
Large spouts in bathrooms for filling bath tubs.
2 Acres on well pump! (i know its only 1/2 acre is allowed. however this is what they did)

Currently when my sprinklers are on the geothermal is barely getting the water it needs. If i try to have the bath tub on it doesn't really work too well.

I love my home, my worry is if im gone and my geothermal and outside sprinlers are on. If my house as a fire, my ceiling sprinklers will not have enough GPM to work.

Well depth- 78 feet
Pump depth 72 feet with 6 feet of stainless
6" casing
well capacity 100GPM per well capacity
My water level is at 7 feet

The company who drilled my well told me you usually get a pump thats 1/2 of what your well is to stay in the save zone so you dont risk running your well dry.

Here is the well pumps I am looking at.

https://www.lockewell.com/pdf/goulds/GS-33-80.pdf

Now, when buying a new well pump. I don't have to get a new motor or controller correct? I can literally just buy the submersible wet end? Something that works with a 2HP controller, I would assume that means i have a 2HP motor attached on it as well?

I am looking at the 55GPM because it has 2 more phases than the 60. That would also reduce electrical cost and it would be less stress on the pump, correct?

The 55GS flow range is 20 – 80 best efficency is 55GPM 7 stages
the 60GS flow range is 40-80 best efficency is 60GPM 5 stages

I dont believe the 40GPM pump would only be 7 extra gallons per minute, which i dont think would help at all. As some zones by themselves bog my well pump down to around 50PSI.

The 55GPM pump has a flow rate of it seems a minimum of 20GPM, as the 60GPM pump seems to have a starting range of 40GPM, Which might be way too much water at start up.

Can anyone else help.

I can get a new old stock 60GS for pretty cheap.
 
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Reach4

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Here is a chart of what a Grundfos 2 HP 40 GPM and 60 GPM pumps do.
What water level are you thinking you can maintain while pumping 40 ?

I wonder if there is a method of shutting down irrigation temporarily when other needs are more pressing.


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Valveman

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Ok as you go up in pressure the volume a pump can produce decreases. You say it is set to maintain 68-75 or so, but it "bogs down" to 50 when the sprinklers are running. Backing into how much a 33GS20 will produce at 70 PSI, and guessing at a draw down of say 20', at 50 PSI the sprinklers are using about 35 GPM. Add to that the 9 GPM the Geo system uses and another 10 GPM for a large house with tub faucets and you get a total demand of about 55 GPM.

You will need a 5HP like the 55GS50, as it will do up to about 65 GPM at 70 PSI from a pumping level of 20'. A 3HP in the 40GS30 will only do about 40 GPM. If you put a 40 GPM pump on that 2HP motor it will only pump about 10 GPM at 80 PSI.

A 2HP can only do 55 GPM at 90', which is the same as lifting 20' from the well and getting 30 PSI. Now you can do this to your existing pump if you add an additional booster pump to pick up the 55 GPM at 30 PSI and boost it to 70 PSI as needed. But it is going to take 5HP anyway you do it. You can have a 2HP well pump and a 3HP booster, or just put in a 5HP well pump.

I would certainly suggest the two pump method because you have a Geo system. A 5HP will not be very efficient or last very long pumping to a 9 GPM Geo system 10-20 hours a day. The Geo will work at 20-30 PSI and the 2HP well pump will be the only one running. But the house and irrigation will get water from the booster pump at 70-80 PSI. That way you use a smaller pump for the Geo and you only have to pay to run 5HP when everything is running at the same time.
 

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Ok as you go up in pressure the volume a pump can produce decreases. You say it is set to maintain 68-75 or so, but it "bogs down" to 50 when the sprinklers are running. Backing into how much a 33GS20 will produce at 70 PSI, and guessing at a draw down of say 20', at 50 PSI the sprinklers are using about 35 GPM. Add to that the 9 GPM the Geo system uses and another 10 GPM for a large house with tub faucets and you get a total demand of about 55 GPM.

You will need a 5HP like the 55GS50, as it will do up to about 65 GPM at 70 PSI from a pumping level of 20'. A 3HP in the 40GS30 will only do about 40 GPM. If you put a 40 GPM pump on that 2HP motor it will only pump about 10 GPM at 80 PSI.

A 2HP can only do 55 GPM at 90', which is the same as lifting 20' from the well and getting 30 PSI. Now you can do this to your existing pump if you add an additional booster pump to pick up the 55 GPM at 30 PSI and boost it to 70 PSI as needed. But it is going to take 5HP anyway you do it. You can have a 2HP well pump and a 3HP booster, or just put in a 5HP well pump.

I would certainly suggest the two pump method because you have a Geo system. A 5HP will not be very efficient or last very long pumping to a 9 GPM Geo system 10-20 hours a day. The Geo will work at 20-30 PSI and the 2HP well pump will be the only one running. But the house and irrigation will get water from the booster pump at 70-80 PSI. That way you use a smaller pump for the Geo and you only have to pay to run 5HP when everything is running at the same time.

You say a 2HP well pump can only do 55GPM at 90 feet. 55GPM about what I would need. My pump is only set at 72 feet down. Maybe i'm misunderstanding, but wouldn't that work?
 

Reach4

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You say a 2HP well pump can only do 55GPM at 90 feet. 55GPM about what I would need. My pump is only set at 72 feet down. Maybe i'm misunderstanding, but wouldn't that work?
The pump setting depth is of little matter, as long as it is below water. What matters is the distance down to the water at a given time.

The 90 he was referring to is the "head", which is what the curves/graphs show. The tables make it simpler IMO.
 
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Edited- I am just looking at the charts for now.

Do well pumps as they age, produce much less GPM then obviously stated. Meaning, if i replaced the pump with the exact same one, could I pick up 4-5 more GPM?
 
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I'm looking at charts, and it seems like the 2Hp 33GPM pump is actually not bad at my high PSI. The pump flows more GPM with less pressure. I am wondering if i can change my PSI range from 68-75 to somethign like 55-60 or something. That should pick me up some GPM. I wonder why it was set that high? I wonder if that much of a reduction would even be a negative thing to do. I'm also curious if the pressure is that high due to the sprinklers in the ceiling.
 

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I calculated your demand to be about 55 GPM. 35 GPM irrigation + 9 GPM HP + 10 GPM house. Your 33GS20 can do that at about 30 PSI. It can do 50 PSI when the demand is 45 GPM as when running irrigation and HP without house use. You never said how much flow or pressure your fire sprinklers needed, and that needs to be the ultimate decider for sizing the pump.

And yes if you can live with 50 PSI you can use a much smaller pump, and the one you have may even suffice. But you said it "bogs down to 50 PSI", which makes me think 50 PSI is not enough for your house. A 2HP pump is already very large and not efficient for a 9 GPM heat pump, that can be done with less than 1/2HP power consumption by itself.

Having only one well pump, the most efficient way to do this is by running the smallest well pump at the lowest pressure the Geo needs, then boost the pressure with another pump when irrigation or house water is needed.
 
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I calculated your demand to be about 55 GPM. 35 GPM irrigation + 9 GPM HP + 10 GPM house. Your 33GS20 can do that at about 30 PSI. It can do 50 PSI when the demand is 45 GPM as when running irrigation and HP without house use. You never said how much flow or pressure your fire sprinklers needed, and that needs to be the ultimate decider for sizing the pump.

And yes if you can live with 50 PSI you can use a much smaller pump, and the one you have may even suffice. But you said it "bogs down to 50 PSI", which makes me think 50 PSI is not enough for your house. A 2HP pump is already very large and not efficient for a 9 GPM heat pump, that can be done with less than 1/2HP power consumption by itself.

Having only one well pump, the most efficient way to do this is by running the smallest well pump at the lowest pressure the Geo needs, then boost the pressure with another pump when irrigation or house water is needed.

Hi Valveman, thank you for constant replying and helping me in this process. I really appreciate it.

I have another question. This is a goulds 33GPM, BF20 controller with a 3 phase 2HP motor.

The pump is also 10 years old, my question is. I'm wondering if when they installed this motor/pump if it was actually enough pressure and volume. Do you think as the pump and motor aged, its just maybe not producing what it use to years ago? I am still getting good volume and pressure, but do you think it could've greatly reduced due to age? Is it maybe not going through all of its stages and curves?
 

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If the system still "bogged down" to 50 PSI when the system was new the pump was just not large enough to start with. If this bogging down to 50 PSI is a new thing, there maybe something wrong with the well or pump. Unless you are pumping a lot of sand, pumps usually do not wear out gradually. They will pump at 100% capacity until the day they stop running. Even when pumping sand many times the motor craps out before the pump. Also if the water level in your well has decreased over time it will cause a reduction in pump performance.

I would more suspect the VFD controller in the Balance Flow system is not letting the pump go to full speed when needed, rather than the pump wearing down gradually. If you have a clip around amp meter you can check to see if the motor is drawing a full load when everything is running at the same time. If the amps are maxed out, the pump is doing all it was ever designed to do.
 
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If the system still "bogged down" to 50 PSI when the system was new the pump was just not large enough to start with. If this bogging down to 50 PSI is a new thing, there maybe something wrong with the well or pump. Unless you are pumping a lot of sand, pumps usually do not wear out gradually. They will pump at 100% capacity until the day they stop running. Even when pumping sand many times the motor craps out before the pump. Also if the water level in your well has decreased over time it will cause a reduction in pump performance.

I would more suspect the VFD controller in the Balance Flow system is not letting the pump go to full speed when needed, rather than the pump wearing down gradually. If you have a clip around amp meter you can check to see if the motor is drawing a full load when everything is running at the same time. If the amps are maxed out, the pump is doing all it was ever designed to do.

Thanks for your replies and help! I appreciate it.

I understand now. I will try and revisit this problem next year when it happens again.
 
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Valveman- call me crazy, but can you link that booster pump you're talking about? Is it just one that will sit on my garage floor?
 
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So you want to boost up to 55 GPM from 30 PSI to 70 PSI?

I need to achieve in total 55GPM at 70 PSI.

I currently have the 2HP, 33GPM pump at 70 PSI.

You think I could just get away with adding a 3HP 33GPM pump? I was able to cut my geothermal down to 7.5GPM. and I will be reducing the volume for my sprinklers.

80 feet at at 60PSI for the 2HP 33GPM pump is 28GPM.
80 feet at 60PSI for the 3hp 33gpm pump is 38GPM.

Can you tell me the math for the GPM at 70 PSI for both the pumps? So if i upgrade to the 3HP pump, how many more GPMS i would actually gaining?

the 3HP pump also has 14 stages, while the 2HP pump as 10 stages. I wonder if I could have my electricity cost near the same even with the 1HP upgrade. Due to more stages on the pump?
 
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Valveman

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A 33GS just can't do more than 50 GPM period. You are still going to need 5 HP to get 55 GPM at 70 PSI. And a 3HP will cost 33% more to run than a 2HP pump. Since you are running a heat pump I would try to keep the well pump as small as possible to save pumping cost. A 40GS20 can do 55 GPM from 80' of head. So if lifting 20' in the well that leaves 60' or 25 PSI at 55 GPM. So you can run the well pump with a 30/50 pressure switch and use a 40 PSI Cycle Stop Valve like the CSV12540-1. The 2HP motor you have will work, you just need to replace the 33GS pump end with a 40GS20. This will give you up to 55 GPM at 25 PSI, which is keeping the well pump as small as possible to be efficient for the heat pump. The heat pump will run fine at the lower pressure.

Then when you need water for the house and/or irrigation, an additional 3HP booster pump will come on that can take the 25 PSI coming from the well pump and boost it to 70 PSI as needed. When irrigation or house water is needed, both the 2HP and 3HP will be running for a total of 5HP. But when only the heat pump is needed, the 2HP pump is the only one running, and the CSV will make it draw as little as 1HP load to keep it efficient.
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Valveman

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Keeping a pump running constantly while the heat pump is on won't use any more energy than letting the pump cycle on and off, as long as you have the right size pump. A 2HP running for an hour will use the same amount of energy as a 5 HP running for 24 minutes. The 2HP will actually use less energy if you add in a few high amp starts for the 5HP. And a 2HP running continuously will last much longer than a 5HP cycling on and off, totaling only 24 minutes of run time per hour.

The booster for house pressure won't run 20-30 minutes per day, and won't even show up on the electric bill.

Got your PM. Hope that helps. Let me know if you need more info.
 

PumpMd

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55gals of drawdown with the heat pump system being at 7.5gpm is 7.33 minutes before your submersible pump will turn back on and run for a little more 1min to fill the pressure tank against what is running, so roughly 9mins for every cycle. Let's just say 9x7 cycles = 63mins roughly 10-11mins of runtime with the 5hp submersible pump and it could be less than that going off of where your static water level will drop too. I bet it's not much seeing how your well makes 100gpm.

That's half less than 24mins of runtime for an hour worth on just your heat pump. The numbers will change with multiple items running at the same time.
 

Valveman

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Two 119 gallon size tanks would only give you 50 gallons of draw down at 60/80 pressure. That would be even more than 160 cycles per day, for a 5HP pump that can only survive a maximum number of 100 cycles per day. Pumps just can't survive that many cycles. That is one reason all the pump manufacturers are pushing those variable speed controllers like the BF20 you have. Even though those variable speed systems cost a lot of money and don't last very long, they are better than cycling a pump to death like that.

As long as your 2HP well pump and the BF20 controller are still working, that pump will supply a lot of water at 30 PSI. So I would set the VFD controller up to run at 30 PSI. Then after the little pressure tank and pressure transducer I would tee in two directions. One side of the tee would go directly to the heat pump, which would have its flow control set to work at 30 PSI. Then the other side of the tee would go through a check valve and then to a 3HP booster pump, CSV3B2T and about a 20-40 gallon size pressure tank with a 60/80 pressure switch. After the CSV and pressure tank for the booster pump, you can tee off to the irrigation and the house.

This way the heat pump runs at 30 PSI, which makes it more efficient and easily supplied by the 2HP well pump. The house will never see pressure lower than 60 PSI, as that is where the booster pump starts. After the booster starts, the CSV3B2T will keep the pressure at a constant 70 PSI, no matter how much or how little the house and/or irrigation is using. Then when no water is being used, the CSV will allow the little pressure tank to fill to 80 PSI, and both pumps will be shut off.

I looked at some pump curves and the best booster I find for this job is a F&W model C22131. It would still be plumbed similar to this drawing.
DUAL PUMP_HEAT PUMP-2 PK1A.jpg
 
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