John, parenthetically, nice job on your WEL implementation.  Your WEL screens provide a lot of additional details to your posting above, BTW.

Best regards,

Bill (WEL0043)

Standing Column Wells (SCW) are an open loop system. Open loops above 50*F only require 1.5 GPM per ton. If EWT's will drop below 50*F 2 GPM per ton is recommended.
 2 Stage units on open loop systems should have 2 flow rates as recommended by the manufacturer (and your quote) to save pumping costs.

2 stage units on closed loops are typically running 3 GPM per ton. Pumping costs on a closed loop system are minimal in comparison and are usually setup at one flow rate.

Unless you have a 9 ton unit it sounds like you are pumping way to much.

I have found on my new Tranquility 27 with a standing column setup that if the water is around 50 degrees, then 1.5 gpm per ton is plenty. However, it is also hard to regulate an exact flow given the pressure swing. Therefore mine is set to around 1.8 gpm per ton at the lowest pressure it sees (around 30 psi). My well so far hasn't dropped below 49 degrees with no bleed yet so no more than 2 gpm is needed so far.

I will assume you have a temp gauge to monitor incoming water temp, and the two HP controlled valves for each stage. Is that correct? Did you have an actual flow meter installed or did your installer rely on the pressure drop chart. Using the pressure drop chart alone to calculate gpm, given the variability of the pressures with a standing column system, wouldn't be wise I would think, but then again I haven't done that.

It looks like you have a 6 ton unit, seems alot for 2500 square feet but maybe its a antique colonial with higher heat loss. You really only need around 2 gpm per ton for two stage operation if the incoming water hovers near 50 degrees, so 12 gpm. You want 67% of the needed flow for stage one, and the other 33% for stage two. Your installer put you at 3 gpm as you know.

My suggestion is to set to 12 gpm and monitor incoming water temps. What is your bleed system? I have an automated bleed using a 24v valve and a Ranco controller. It could be with or without bleed you can maintain a well temp around 50 degrees all winter and have no need to increase flow. If the water temp starts dropping below 50 by a few degrees, you can add a couple gpm. If it really drops down to mid to low 40s even with bleed then go to the 18 gpm total flow on two stage.

Steve,

I have two Blue-White flow meters installed. One on the bleed line the other on the return line to the well. I do have temp. sensors measuring every temperature you can image using the welserver kit. Great for debugging BTW.

http://welserver.com/WEL0167/

Yes, I have a 6 ton system and my house is 16 years old. So I think you are correct in that my system may be over sized. Partly my fault as at the time I though aux heat turning on was something to avoid. So the installer may have size the system so Aux heat never turns on except with a system a failure.

I do have an automatic bleed system. Currently set to start bleeding at 47F. Using a ball valve I currently have the bleed rate set a 1.5gpm. So far this seems to hold the temp at ~46F on the cold days. As you may have noticed on my wel page I have a fairly shallow well. So I'm bleeding as I type this. :-)

My system only has one HP control valve with a 18gpm flow regulator. That's why I'm looking to add another control valve and replace the 18gpm flow regulator with a 12gpm regulator. Then add the second control valve and 6gpm flow regulator when the second stage kicks in.

If I do this I will lose the some flexibility of setting the flow rate. If the EWT temp. drops to low I can always increase the rate on the bleed line. The well produces 13gpm so I do have some flexibility with the bleed rate.

I missed all the data you had when I wrote my response, and was just looking at your welserver info. I've seen that once before but never really looked at the data output. Very cool. I might need to get that since the data is fantastic.

380' is shallow for 6 tons but since you should be able to run 1st stage most of the time (really 4 tons) then its not too shallow for that.  Mine is 400' with a 5 ton system.

I've only been running for a little over a month.  What I'm running into now is the pump situation.  I'm using my existing pump which puts out enough volume no problem, but is a 2 wire non-variable.  It was replaced about 7 years ago before we moved in and I don't have the specs.  My guess is a 3/4 hp which usually draw around 6 amps, or about 1350 watts. 
My pump is set at 300' in the well with static water level at 13'.  I started monitoring usage and it appears my electric use is way too high. 

Steve, did you measure the AMPS? The watts does sounds a little high. I assume your pumping 9gpm based on your 5 ton system and 1.8gpm. With my variable speed pump I draw 1250 watts at 12gpm and 1900 watts at 18gpm.

My well situation is worse then indicated. It's a 380 foot well with ~80' static. I live on a hill so static is pretty high. I make up for the lack of water column by bleeding. That's why I'm also looking at ways to reduce the cost of running the heat pump. That said my overall heating/cooling cost will be significantly less this year then last. I'll post this years cost later this month but YTD I'm at a little over $2500 for electricity and oil compared to last years $4171.

How high is your electric use? Again I'm posting the monthly cost of running the HP and WP on the WEL page. In Nov. the cost was $64.10. I expect the in next few months I'll see significant increase in my electric bill but hopefully still cheaper then heating oil.

I need to get a new ammeter and get some actual readings from my pump. Watts=amps x volts so I was just guesstimating.
Unfortunately I hadn't been recording data (still love your welserver system) until a couple days ago. Up until now I have just been keeping an eye on the units to make sure they were running well in terms of air temp rise and water temp reduction, which have been within specs.

What shocked me was it appears I'm using 100 kwh per day, but still need more data to confirm. In MA electricity is 17.4 cents/kwh. I don't have a 3rd stage resistance coil backup either, but so far even at our coldest night at 22 degrees both units kept up in single stage fine and weren't even running all the time (lots, but not constant).
So, at that rate I'm looking at $522/month which I guess shocked me, but let me think out-loud here. This of course it includes my normal electrical use and my house is now 100% electric. A normal electric bill pre-HP with no AC use was around $180. I still need a second storage tank before I was going to connect desuperheater, but I hear in winter the benefits are minimal. But there is savings there.

So I guess I would be paying around $350 month for the heat portion. More than I expected but a good deal less than the gas cost me. Again this is extrapolated from little data and I will see as we progress into January.

Also, I'm keeping track of the daily mean temp and heating degree days number from weatherunderground.com so I can see if there is a predicable correlation between electricity used per heating degree day unit.

jpespisa

                         ---Stg 2 Sol Valve-------4GPM Flow Cont---
                        |                                                                 |
Source Out---------Stg 1 Sol Valve-------8GPM Flow Cont--------12 GPM Total Flow

No need to increase flow beyond that for a 6 ton system with SCW. The bleed control will take care of the system EWT.



stevecaz

DSH output is not minimal in a heating dominant climate. The DSH, although parasitic in heating mode, is producing hot water at the COP of the heat pump system. That is quite significant compared to an electric water heater.

SteveCaz ~
Regarding benefits to the hot water heater, I have found that in our home we use approximately 7-12 kwhrs less per day to heat our hot water when we are in heating mode.

I also expected minimal benefits in the winter, but my submeter tells me that when the geo system is not running we give 10-15 kwhrs per day to our HWH and when we are heating the house 1-3 kwhrs per day are sent to the HWH. I was surprised by this, but at least it's a pleasant surprise.

Now, I have a 3 ton closed loop waterfurnace - so this may be totally different than your setup and you may not realize the savings that I do... frankly, I don't completely understand why I am saving the amount that I do.

Joe

You really think I can run the system on 8gpm? The normal water temp of my well is ~52F. The bleed Sol valve opens when EWT reaches 47F actually 46F because the controller is slightly off. The Climatemaster manual recommends 2gpm per ton when EWT is below 50F.

NOTE: When EWT is below 50°F [10°C], a minimum of 2
gpm per ton (2.6 l/m per kW) is required.

I could give it a try. I just don't want to trigger any lockouts.

Steve,

It sounds like are systems and electric bills are very similar. I'm also 100% electric and live in MA so are climate is also comparable. One big difference is the electric rates we are paying. Mine is currently .0949 cents per Kwh. I must use more electricity then you because my electric bill is in the $180/ month range w/o the HP. Anyway as you can see I'm tracking the cost very closely. So far for the month of Dec. I'm at $32.50. We are about 1/3 through the month so I'm estimating the HP/WP cost to be a little over $100 for the month depending on how much colder it gets. If I doubled that for your rates it would still be far less then your estimate. So hopefully your estimates are off. :-)

Regarding the HWG. I think I am getting some benefit. My HP typically runs in 12min cycles. But that includes the blower startup and 90 seconds the blower runs after the compressor shuts off. From what I have observed that's not long enough to really heat up my HWH. If I raise the thermostat which triggers a longer cycle times then I observe the HWG raising the water in the bottom of the HWH to over 100F. Still it's better then no HWG. BTW the HWG is useless in the summer when the AC is running.

John - I'm on NSTAR in Ashland but we must have very similar electric rates given the regulation here. I believe the rate you stated is the actual electricity cost. But then they add a meter cost, transmission line cost and any other charges they can make up - last I looked up it was in the range of 17 cents per kwh.

I just found the latest press release from NSTAR from November on rates going down, but check this out:

"Though delivery charges vary slightly by region, the Basic Service supply price for all residential customers will drop by 3.7 percent, from 9.22 cents to 8.88 cents per kilowatt-hour. Customers of the former Boston Edison Company using an average of 500 kilowatt-hours per month will see their total bill drop from $88.56 to $86.86."

You mentioned your rate at $0.0949 which compares to NSTAR's $0.0922 which is going down to $0.0888. As far as I know, that is the actual electricity cost but not the whole cost.  Notice the "delivery charges" mention. Using their example for 500 kwh of $88.56 at a $0.0922 rate, that equals $0.1771/kwh. All those delivery charges make up the roughly extra 8 cents difference.

And finally, the HWG should be at its best in the summer providing more hot water than you can use. Thats when it has the most heat to shed.

I have thought about changing the CPH. I think the defaullt for the thermostat is around 5 CPH but very rarely does the system go over 3. As you mentioned my only reluctance is the temperture swiings. I remember the days of the oil furnace and feeling the chill in the air waiting for it to kick on. But it's and easy change on the thermostat so I think I will give it a try and see what happens. I'm sure the wife will tell me if there is an issue or not. :-)

Regarding hot water production by DSH in winter, I have results similar to Ona’s. Cold weather (night temps ≤ 25˚) means long system runs, and 50 gallons of water cheaply heated to 125˚, hotter than the water in the powered tank, set at 120

Last winter, my Climatemaster thermostat had a first stage temp differential setting of 1˚. This resulted in short run times, mostly about 12 minutes each. I changed the differential to 2˚ and increased the set point from 70˚ to 71˚. This kept the temp swings between 69˚ and 71˚ and increased run times and hot water production. Compressors do better with fewer ons and offs.

This year I am also heating my unfinished basement, where uninsulated ducts reside. This is keeping hard floors warmer and lowering heat loss from the main floor. I expect an increase in my elecric useage for this change.

Last summer I had a situation similar to jpespisa’s, system run times were too short and only for dehumidification, practically no hot water was generated by DSH.

Regards,

Masoud

jpespisa, 5 CPH sounds very high to me. I forgot to mention that dehumidification in cooling mode will be better with longer run times as well.
You can try setting the CPH to 2 and not mentioning it to the wife. I told my wife what I was doing, but fortunately she didn't notice any temperature difference. In hindsight, I would have changed the setting and not mentioned it. If still no comment regarding her being too cold after 3 months, I would either not mention it at all, or more likely mention that I changed it and tell her about all the benefits we are receiving from it. And after she wakes up, we'd talk about something else.

P.S.  The only thing I would look out for is second stage engaging more than before due to the temperature swing being slightly higher.  I wouldn't think this would be an issue, but it is possible I suppose.  I'm not familiar with open loop systems.

Steve,

Actually my rates are low. We have our own electric company up here in Boxborough. Littleton Electric Light. Our rate is .0829 with a .015 cent delivery charge. Then a .003 PASNY credit is added.

http://www.lelwd.com/documents/LELDrateslowestinstateNovember2009.pdf

Masoud,

Thanks for the tip. I never noticed the option to change the temp differential on my thermostat. I have the Honeywell 8000 series. I'll take another look. Sounds like that explains the poor HWG performance I observed in the summer.

Please let me know if you find a differential setting on a Honeywell. If not, reducing the CHP should also result in a longer run time.

You may also find a setting for Less Aggressive, Standard and More Aggressive. I like Less Aggressive the best for heating. According to Honeywell, this setting "Applies to recovery ramp and use of auxiliary heat". My interpretation of this statement is that Less Aggressive will provide longer run times between stages, More Aggressive would provide the least run time between stages, and Normal would be whatever Honeywell believes is the standard run time between stages. I have noticed this occur while experimenting with our thermostat.

I tried, but couldn't get Honeywell to confirm this to me (citing proprietary information). In my experience, getting someone on the phone from Honeywell that won't just read you the manual and where English is their native language (not busting on foreigners, it's just that communication can sometimes be difficult) is nearly impossible. That being said, I love our Honeywell Prestige thermostats.

WOW - I am shocked....at how much I'm getting hosed. 

Since I get ebills and haven't really looked at one lately. 

OK, I just looked it up for confirmation.  Starting Jan 1 with some new rates, the cost per kwh is $0.0888 for service PLUS $0.07206 for a total of $0.1609/kwh.  Then they also tack on $6.43 to each bill for what they call a "customer" charge.