Open loop geo system costing too much to operate
Last Post 01 Mar 2015 10:04 AM by xscash. 10 Replies.
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rroy36User is Offline
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28 Feb 2015 10:01 AM
When the well was drilled, they went down to around 600' before stopping and even then it had to be hydrofracked to get 5-6 gpm. Because it's so deep. a 1hp well pump was installed. That 1hp motor is using a lot of electricity. We had a very cold February this year and my electricity usage was 2991 kWh. My system is a Waterfurnace Premier 2 using 2 Taco values (another very expensive part). My question is "is it possible to raise the well pump in order to reduce the size to a 1/2hp motor?" I just don't know if something like that is done in an already drilled deep well. Since it was hydrofracked, I'm thinking that I might be able to get enough water at a shallower level.

Anyone know if it's possible?

thx,
Rob
jonrUser is Offline
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28 Feb 2015 02:01 PM
What is the water level in the well? How many tons is the heat pump?
rroy36User is Offline
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28 Feb 2015 05:06 PM
I don't know how many tons. I just know its a Water Furnace AT045 2-Speed Heat Pump. The last time I had to have my well pump replaced, I looked down the hole and I could see the water level didn't seem that far down, 40 to 50 feet maybe. I had a return line put in during the initial installation and it goes down at least 100'.
Palace GeothermalUser is Offline
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28 Feb 2015 05:39 PM
If the water level is 50' and your pump is down 500', you are only lifting the water 50'
Dewayne Dean

<br>www.PalaceGeothermal.com<br>Why settle for 90% when you can have 400%<br>We heat and cool with dirt!<br>visit- http://welserver.com/WEL0114/- to see my system
marmarUser is Offline
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28 Feb 2015 05:50 PM
You can easily lift 50' with a 1/4 H.P. if you are you are sure that is your static well water level?
arkie6User is Offline
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28 Feb 2015 06:06 PM
Raising the pump in the well won't make any significant difference. The static height of the water above the pump increases the pressure at the suction of the pump, so the net pump lift is just the height from the actual water level to the height of the discharge plus and restrictions in the line. The only thing moving the pump up would do is reduce the feet of pipe that the pump has to push water through, but the well pipe should be sized sufficiently for the expected flow rate such that a straight run of pipe shouldn't offer significant resistance.

You need to know the size of the heat pump to determine the required flow rate. An 045 sounds like a 4 ton unit. That would require approximately 2 gpm x 4 ton = 8 gpm of flow of groundwater. That is near the upper limit of a 1/2 HP well pump unless you can lower the pump discharge pressure. Is this well pump also used for domestic water? If not, you could lower the pump pressure via the pressure control switch or operate it under a on/off control scheme with only the discharge pressure needed to meet the flow needed.

But a near continuous draw down of a well that produces only 5-6 gpm at 8-10 gpm flow rate would cause the static water level to drop significantly and it might get to the point that a 1/2 HP pump couldn't overcome the necessary lift.  edit:  I just went back and read subsequent posts and it looks like you are returning the heat pump flow back to the well, so, disregard this comment on draw down.
marmarUser is Offline
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28 Feb 2015 08:39 PM
It was very cold in Central PA in February and my electric usage was 2400KWh, probably the highest usage in the 4 years since I have had Geo. Less than 2000 sq. ft.
rroy36User is Offline
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01 Mar 2015 08:29 AM
Thank you all for the info. The well is used for both domestic water and the geo system. My unit must be a 3 ton unit since the water draw is 6 gpm (2 Taco valves drawing 3 gpm each). If I can reduce the size of the pump, that will reduce the amount of electricity used and thereby reducing my electric bill.
In order to save wear and tear on the pump from starting and stopping frequently during winter months, I was told to add a constant pressure controller (which I did) and that should help me save on electricity. Doesn't seem like it did much of anything in that regard but I do believe it helped on the wear and tear of the pump. I've had to replace the pump 3 times in 5-6 years until the constant pressure controller was installed.
joe.amiUser is Offline
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01 Mar 2015 08:32 AM
Ask your propane neighbors if they'll take your ~$300 heating bill marmar. Sounds like you are doing great.
Joe Hardin
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marmarUser is Offline
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01 Mar 2015 09:50 AM
I'm not complaining at all--just making reference to rroy36 comment about using 2900kwH. That's my electric and heat bill. Most people with Penelec(First Energy)here in central PA have power bill alone $100-$150.
xscashUser is Offline
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01 Mar 2015 10:04 AM
you need to consider gallons per min used by domestic and by the geo when picking a pump size. You can reduce HP and lower energy cost but you will need to make sure you produce enough water(GPM) for both. I figure for my application 5 gpm for domestic plus geo use. your setup would be 10-11gpm at your static water level. with your refresh rate your static should remain constant unless you add irrigation. look for a 1/2-3/4 pump with a pressure you desire at your static level that will produce 10-11 gpm. lower the hp better the savings. I had a 1.5hp pump in my setup and reduced it to 1hp and saved $100/mo.
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