Most efficient pump 9 GPM, 3 ton heat pump

[Flimboyz]

Hello, i would like to know what is the most efficient well pump setup for my geothermal heat pump.
My house are supplied by an other pump.

My need:
5 GPM stage 1 controled by Dole valve 30% time cooling
+4 GPM stage 2 controled by second Dole valve 70% time heating
9 GPM total
4 PSI drop at heat exchanger

My well:
6" bore
127'
Water level not in use, 6'
Lowest water level, 25', +22 GPM
1" x 70' horizontal pipe to house

Thank you

 

[Reach4]

You might look at the Grundfos 10S03-6 , which is a 1/3 HP submersible. There may be something better.

 

[Sponsor]

 

[Flimboyz]

Thank you,
Yes i'm actually looking for 1/3 HP, but not sure about the pump end.
I found an old post from valveman promote the use of a modified pump end.

But I'm also considering 1/2 HP 3 phase VFD controlled.
With a VFD, I would not use Dole valves, I would program speed by input.

 

[Valveman]

I hear from a lot of people with heat pumps. They tell me it doesn't matter how much energy the heat pump saves if they have to replace the variable speed well pump too often. Because you do not use this pump for the house, the geo can work at like 20 PSI. I looked up the pump curves and at that low pressure a VFD could save you 10 bucks a month if you ran stage one 24 hours a day. You need to do the math to see if saving 10 bucks a month will pay for a new variable speed pump and/or controller every 5 years or so, compared to a normal 10S05-6 pump which could last 30 years.

 

[Flimboyz]

Thank you Valveman, I know your point of view, I have already bought a CSV for my current setup, I have an 1 HP for both the house and the Geo.

I want a new pump only for the Geo, and it should not use more than 300 Watts.
If you can help me finding the right pump, I would really appreciate.

In this particular case, I'm relly looking for the most efficient, lowest energy use.

Thank you.

 

[Valveman]

1/3HP is the smallest pump you can get, and I think it will still use 600 watts or so. 1/3HP is 780 watts max. If you use a variable speed drive you maybe able to slow it down to about 400 watts. But at max flow it is still going to need to draw about 700 watts.