My first posting in this forum. We moved into a new house in Dec 2014 and have installed the following: - Waterfurnace series 7, NVV060 - 5 ton split into 3 zones. - Intellizone 2 with 3 zones - House is 2 storey colonial about 3700SF - I have an open loop well. The well is 600' deep. pump at 140', water table at 20' incoming water temp is currently at 50 degrees and exiting around 45 - Pump is Goulds 18GS07 . 18 GPM and peaks at 26 GPM - Controller is CentriPro Model CB07412, HP3/4, V 230, 7.2 AMP, - Stoneham, MA - New construction, HERS rated at 33. all LED bulbs and high efficiency appliances. R28 Walls, great insulation and air tight - HRV geo valve is set at 90% opening making the flow at 26 GPM. if we reduce the valve opening, then the water sound is loud) Here is my issue, after running the system for a month, its awesome and we love it until i got the electrical bill. From a Waterfrunace perspective, the thermostat does energy consumption and is recording that i used 838kW in Jan. Which is averaging about 28 kW per day. No issues there, I only had electrical aux heat kickin for 30 minutes the whole month, based thermostat display. The house consumption for the month was 2700kW. So where is the whole draw coming from? I called my electrician and he brought his probe: Geo is using about 5 to 11 amps Pump using around 7 amps (consistent) I forced the geo to go into electrical aux, and it was using 50 to 65 amps (which is expected) based on my simple calculations (7 amps * 230V = 1.6kW/hour. geo runs for 20 hours/day = 32 kW per day x 30 days = 966 kW), the pump is consuming as much power as the geo during the month. The Geo used 838 kW in Jan for geo, the pump is using more. which is really crazy!!!! Considering how Cold Jan was what the geo consumed sounded reasonable and within the estimates that was provided by the geo installer the electrician measured the power at the panel incoming wires, and it registered 17.5 AMP. (inside the house). the pump and geo were running. My geo installer suggested to replace the pump with a variable speed pump and controller/drive, but did not recommend any and mentioned that he does not sell them either. My pump dealer, (GOULDS), has no idea on how to make the pump work with the variable speed control and the geo. My questions: what is the appropriate pump size/type or brand or specs for such a system? Anyone with a variable speed pump can share pump consumption data. If using a variable speed pumps, what is the typical usage of those pumps? brands? I know that the thermostat meters power consumption used by the geo, however, the pump is not metered. Can it be metered? Which pump can be metered by the pump my pump dealer suggests adding a variable speed controller to the same pump, is this right? my geo guy says that the gep demand for flow can range from 6 GPM to 18 GPM. that is why he is recommending a variable speed. I'm not sure what to do? Any help here would be greatly appreciated. !!!!

You can't convert a typical well pump to variable speed*. So look at a 1/2 HP Grundfos SQE series pump selected specifically for your head (minimal) and flow requirements. Perhaps a 115V model which could be wired to allow use of a Kill-A-Watt meter.

* edit: maybe with a Franklin Monodrive

Yes they make constant pressure pumps. Look at a WEL system (web energy logger) to monitor whatever you like.

I'm pretty sure just switching to a variable speed pump (without changing anything else) will not save you very much...... in fact depending on the existing pump selection and a potential variable speed pump selection it wouldn't be impossible to have a scenario where the "upgrade" to variable speed would cost you more in pumping power.

I too have an open loop system that I designed and installed myself. From the sound of it, your system is working fine as it was installed, your problem is you are just pumping about 3 times (26 gpm!?!) as much water as you need. One rule of thumb I've heard for geo units with EWT 50 degrees and above is 1.5 gpm/ton = 7.5 gpm in your case. You need reduce the flow through your unit. Simple way is closing the "geo valve" you are referring to. Dealing with the sound is a separate problem with some simple solutions.

To address the sound problem, you can....
1. Relocate the throttling valve to a location where the sound isn't a concern.
2. Insulate around the valve (not recommended as it isn't very effect, since the sound tends to travel down the pipe, especially if it is copper ask me how I know?? ).
3. Add an additional valve upstream and close both equally to get the reduction in flow (this will divide the pressure drop needed to produce the reduced flow between the (2) valves). At one point, in my system I had 3 valves in series, however I don't recommend that because anytime you need to adjust the flow (I like to tweak things ) I would then have to do a tedious iterative process of readjusting the 3 valves to get the correct end result flow and chase the water noise from one to the other and then out, which was a bit of a chore. So eventually I removed the additional valves and used option 4.
4. Replace a section of the piping with reduced diameter. I originally had 16" long 3/4" diameter braided stainless hoses connecting my unit to the piping, so I just experimented with smaller hose diamater's and found that the (1) 3/8" hose was enough (left the other line 3/4" hose), I was only getting slightly more flow than design and no noise, because the pressure drop / restriction in the hose is distributed along the length so no noise. This was a clean and cheap fix and eliminated all the noise.

Reducing the flow through your geo unit (to the recommended value) will reduce you power consumption dramatically, but will increase how often your pump cycles on and off (which in general will reduce the life of your pump). The pump cycle frequency is dependent on the flow capacity of your pump and the size of your pressure tank. Typically to account for this open loop systems have either....a traditional pressure switch controlled well pump with extra pressure tank capacity/volume (2 or 3 tanks instead of one, or just (1) much larger tank) OR a variable speed "constant pressure" system that uses a pump speed controller or VFD that runs a 3 phase pump. I have the constant pressure variable speed system and it has worked well for 6 years now (this system type also allows for a reduced size 2-4 gallon pressure tank). This system typically utilizes a 3 phase motor (controller converts house single phase to 3 phase), which reduces wire size requirements down to the pump, and the controller acts as a soft starter to limit inrush and extend the motor life. Most important the constant pressure system keeps the pump running any time there is a demand for water, so the pump doesn't cycle during extended moderate or low water draws (like the geo unit). The pump is controlled to run at the speed required for the current pressure and flow demand. There are some "nice to have" diagnostics often built into the constant pressure variable speed controller to indicate low water table, locked impeller, loose wire, pipe leak, and some others.

If your static water level in the casing is really at 20' below the surface, then you have a pretty ideal setting for pump and dump since your pump is only lifting it 20', and your pumping power should be pretty reasonable. Mine is lifting quite a bit further and at 6 gpm through my unit, it draws about 800 watts.

Maybe some experts can correct or confirm the above.