Open-Loop Geothermal 2-stage Operation

Fathompin · 01-03-17, 01:42 PM

My Brother has an open-loop well geothermal system that was giving him problems. I was called in to help because he was not real happy with the last service call. I found his problem, but now I have a few questions about the operation of his system that perhaps could be answered on this forum (and then I won’t have to do too much outside digging for the answers)…thanks in advance:

Two-stage heating and cooling:
Considering the higher efficiency of a low-load heat pump setting in a two load system, how does that compete with well pump cycling over longer time period? He has a pretty big well pressure tank (> or = 30 gals?) and a well that has pumped plenty of water over 20 years use. His thermostat is not set to the two stage load operation now (but can be) and I wonder if that was on purpose or not. If it is on purpose, then I assume somebody decided that drawing a lot of water could keep the well pump cycling less; i.e. pumps over shorter time periods, potentially shorter cycling times, and definitely longer off time intervals. Compared to low water flow for the low load heat pump setting, the pump will cycle constantly over longer time period and this may not be best approach. Hence, what is the best practice in this case?
(for example, if he installed a cycle stop valve on the well, I'd probably choose to maximize water flow at all times and reduce well pump time on.)

Also, out of curiosity I'm just wondering; is wiring the well water valves directly to the thermostat "Y & Y2 call for heat/cool" the best practice? I ask because when the compressor shuts off (due to problem, I know not the usual operation), thermostat calls for heat means the well pump keeps pumping and dumping water until somebody notices the red light on. Off-hand, I don't see a better way to control the water valve from the heat pump controls, I only see that the best way is a parallel connection from the thermostat call for heat/cool to the valves and the heat pump control, especially the two-stage setup, because the valves need to stay independent, which is what Y and Y2 are.

Thanks.

01-03-17, 01:42 PM	#1
Fathompin Lurking Renovator Join Date: Nov 2015 Location: Dayton Ohio Posts: 12 Thanks: 1 Thanked 1 Time in 1 Post	Open-Loop Geothermal 2-stage Operation My Brother has an open-loop well geothermal system that was giving him problems. I was called in to help because he was not real happy with the last service call. I found his problem, but now I have a few questions about the operation of his system that perhaps could be answered on this forum (and then I won’t have to do too much outside digging for the answers)…thanks in advance: Two-stage heating and cooling: Considering the higher efficiency of a low-load heat pump setting in a two load system, how does that compete with well pump cycling over longer time period? He has a pretty big well pressure tank (> or = 30 gals?) and a well that has pumped plenty of water over 20 years use. His thermostat is not set to the two stage load operation now (but can be) and I wonder if that was on purpose or not. If it is on purpose, then I assume somebody decided that drawing a lot of water could keep the well pump cycling less; i.e. pumps over shorter time periods, potentially shorter cycling times, and definitely longer off time intervals. Compared to low water flow for the low load heat pump setting, the pump will cycle constantly over longer time period and this may not be best approach. Hence, what is the best practice in this case? (for example, if he installed a cycle stop valve on the well, I'd probably choose to maximize water flow at all times and reduce well pump time on.) Also, out of curiosity I'm just wondering; is wiring the well water valves directly to the thermostat "Y & Y2 call for heat/cool" the best practice? I ask because when the compressor shuts off (due to problem, I know not the usual operation), thermostat calls for heat means the well pump keeps pumping and dumping water until somebody notices the red light on. Off-hand, I don't see a better way to control the water valve from the heat pump controls, I only see that the best way is a parallel connection from the thermostat call for heat/cool to the valves and the heat pump control, especially the two-stage setup, because the valves need to stay independent, which is what Y and Y2 are. Thanks.