These are my setup test numbers for my 4 T Water-to-Air Hp. (Northeast).

I think the flow rate is a little high.

Your thoughts?

I see that the water pressure only needs to be at 21 psi and yet the HP has my well pump running at 30 to 50 psi.

Seems like a waste of $$$. Any way at getting around this? Two well pumps?

Wasn't sure what you meant by flow rate too high, now I get it.
Frankly if your well is 30-50 PSI, I don't see how entering water pressure is only 21 unless you are running water elsewhere.
It is almost closer to low closed loop numbers....
There are variable speed well pumps that ramp up/down based on demand. They are a good fit for geo.
J

I understand that HP's require high gpm but low psi.

As for a new pump, I've been looking at Franklin's Mono Drive - good for any 3 wire pump, Grundfos' SQE variable speed constant pressure system - a matched setup, and I even read about constant pressure valves.

What's the current preferred choice???

Dancour, assuming your 3 psi Delta Pressure numbers are accurate, I estimate your flow rate to be about 11 gpm.  As you note, this is higher than needed for an open loop/well water system.  For your 4 ton unit, again for an open loop/well water system, I believe you need about 6 gpm.

Best regards,

Bill

I'm still not sure numbers are valid on entering water pressure.
I'm also not crazy about tight flow (6 gpm for 4 ton) though most manufacturers suggest 1.5-2 GPM. I lean towards 2 GPM.
That said, you don't need 11.
Still don't get your readings on the start-up sheet. Convention well pressures tend to fluctuate, so I'm suprised that both heating and a/c numbers are identical (I'm wondering if responses are canned by a bored tech whose done this a thousand times before).
Did not see any entering water flow restriction on the entering side in your pictures (unless it's further upstream) so how are you getting 21 PSI from a well operating at 30 to 50? High flows (gpm) and high (water temp) delta t's do not typically go hand in hand either. I do not have a Waterfurnace chart though so I can't tell you what their book says.
J

30 Delta T seems a bit high for cooling

Thanks Bill, I checked with the installer and he said that he left the flow rate at 9.8 gpm to keep the pump from cycling. I think I'll look for an inline flow gauge.

I did find this chart in the WF manual.

Dancour, yes, I used the chart you illustrated to estimate 11 gpm.  Pretty close to the actual of 9.8 gpm.

I have the same WF equipment as you, except my units are 3 and 5 ton.

I don't have difficulty getting above 30° air DeltaT across the evaporator coil with my 3 ton unit - see http://welserver.com/cgi-bin/plot/WEL0043/AirDeltaT-EvapCoil-3TonUnit.gif .  But I can't get much past 20° air DeltaT with my 5 ton unit - see http://welserver.com/cgi-bin/plot/WEL0043/SampledAirDeltaT-EvapCoils.gif .

Reason is air DeltaT is highly dependent on ECM blower motor speed.  I probably have my 5 ton unit's speed set too high.  I know my 3 ton unit's speeds are set low because I have 3 zones attached to the 3 ton unit, thus making it hard to have the correct air velocity in many situations.

Best regards,

Bill

I would suggest a cycle stop valve (CSV) to provide a constant pressure and to eliminate pump cycling. If you read some of the pumping threads at Terry Love's plumbing forum, you'll see the issues with the variable rate pumps. Two pumps is the best solution, but I still would use a CSV on each pump.
 
Do you have flow numbers from both stages of you furnace? In the pics in the other thread it looks like you have two valves, and flow adjustments for 1st and 2nd stage. Did the installer test 2nd stage?

Thanks Project_X, I took a look at that site, It seemed to have a bias towards the CSV which is,as far as I can gather, a pressure relief valve with a hole in it that keeps your pump working longer and harder but not cycling so often. Have you used one for a number of years? I heard about a “Dole flow control valve” that might work.

and yes, 2 stages tested.

I'm very happy with my CSV, i've had it installed for about 6 months to combat the cycling issue. The CSV is basically an flexible orifice, that opens as the required flow increases to preserve the set pressure.

The results you posted at the start of this thread look to only be from a single stage, do you have the results from the other stage?

Also, do you know what the flow rate for stage two is? It looks like you have two separate valves.

Thanks for sharing your experience with the CSV.

Did you go ahead on the booster pump system you were working on?

I don’t have the specs from stage 2 in front of me, but I would guess 11 gpm @ 3.6 psi. Hopefully I won’t be using stage 2 very often. We will reducing the flow rate shortly.

I haven't done an alternate pumping arrangement yet. I haven't decided if it is worth the cost until my well pump goes (it is brand new).