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Forums > Green Building Technologies > Geothermal Heat Pumps > Subject: open or closed loop

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duck79

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Posts:5

07/04/2009 7:21 AM
I am building a new home on a large very clear, rocky lake in the Ozarks. My lake front property has access to deep water. The lake drops to 30 feet deep 100 feet from the bank and is deeper yet further out. In my current home I have an open loop (well) system and like its simplicity. Is there any benefit to an open loop system with it's extra electric costs for pumping the water 200 feet laterally and raising it 60 feet from the lake. Or, are there fewer complications putting a closed loop coil in the lake.

jonr

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Posts:330

07/04/2009 10:51 AM
If you put the water directly back in the lake or used a closed loop, the the 60' of lift is canceled out by the water running back downhill. A closed loop will make freezing easier to protect against.

duck79

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07/04/2009 11:49 AM
I intend to put the water back in the lake via a decorative creek bed.

fsq4cw

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Posts:26

07/04/2009 11:28 PM
Open loop may be more efficient, paricularly if cooling is large requirement, as this may be able to be done passively if the water is cold enough. However, be prepared for more loop maintenance with open loop. SR

engineer

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Posts:1135

07/05/2009 8:23 AM
Pumping open loop water up that high may add enough extra power cost to overcome the improved efficiency of open loop. OTOH an issue with closed loop is keeping it safe from marine traffic and fishermens' gear

Without data, you only have an opinion.

Alton

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Posts:661

07/05/2009 9:29 AM
duck79, If you do use an open loop, be sure that the pickup and return are not on the bottom of the lake. No worry about the return if you use a decorative creek bed. Maybe you could get the pumps sized for an open and closed loop system to compare the electrical use.

Alton C. Keown Residential Designer and Construction Technology Consultant Auburn, Alabama E-mail: alton at auburn dot edu

jonr

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Posts:330

07/05/2009 4:40 PM
If you pump and dump at the top, then you have to put the pump near the bottom (the lake). So you need a long wiring run. I'd just go closed loop.

joe.ami

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Posts:1401

07/05/2009 9:33 PM
First question is what's in the water? Clear doesn't mean it's suitable. Filtration would be employed and could easily require more care than your current system. Good Luck, Joe

Just a Mechanic; Geothermal; Savings Underfoot

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Forums > Green Building Technologies > Geothermal Heat Pumps > open or closed loop

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