New York 7 series well pump ?

Have been looking into a 7 series to replace my 17yr old WF versatec unit.
Open loop pump and dump system.

My question is with the 7 series running constantly will my electric bill go up because my well pump will be running constantly? Will my pump burn out because of this? Would I be better off with a 5 series? Or replace my well pump? I do not know if my well pump is variable speed or not as I just bought this house.

 

I believe Doc said once that the 7 series should be on a closed loop, but I'm not sure.

 

In another thread he said "7 series with open system is tricky, hard to set up since it runs forever,and the well pump would run forever, and you need a variable speed well pump to make this efficient".

My question is, is a 5 series still less efficient then a 7 series without a variable speed pump?

 

I have a 5 series and from what I read the 7 series is about 20% more efficient.

 

Yes, the heat pump itself is 20% more efficient. But that does not help if you are now spending 30% of whole System energy more on pumping.

http://welserver.com/WEL0762/

Here is an example of an open well feed (3) 7 series heat pumps, a 3, 4 and a 5 ton.

The graph on the bottom is the energy use of the variable speed well pump (pumping for all (3) 7-series) and the single 4-ton 7 series over the last 6 1/2 months.

You can see, the variable speed well pump uses about as much energy (serving 3 heatpumps) as the single 7 series 4 ton, about 30% of the total system power.

Now, this data is a bit misleading, since the efficiency is also much higher when exposed to 50F water. So you pay more for the well pump running, but less for the 7 series running (about 20-30% less). Plus it runs less time, since it has more capacity, and uses less supplement heat.

The difference in efficiency between 30F and 50F in entering water temperature is about 23.6% for the 7 series. But average annual loop temperature for closed loop is around 41F, so I'd say the advantage is about 12-13%.

So we are looking at 3-5% pumping power for the closed loop circulation pump (modern ECM, much more for constant speed), and about a 13% hit for closed loop performance, offset by 30% penalty for pumping. Thus I would say if this is done well, you are looking at a 12-15% penalty for an open system.



If you don't watch out and put a constant speed well pump on a variable speed, and understand that, you will be killing yourself in higher pumping costs.

 

Should I just go with the 5 series then? Is it worth all the additional cost for the 7 series? new well pump and all that.

 

I love the 7 series, and if I were you, I would get a small variable speed well pump. The costs you spend on the well pump are also subject to the tax credits.....

 

Oh good to know!

 

Add in the install cost for said unreliable pump and you are out thousands upon thousands. Keep it simple. 7 series ain't the end all be all. If it can print money, I'd buy one.

 

$100-300 to test well from quotes I've gotten. Then install the pump. Plus cost of 7 series. Kinda leaning towards going with the 5 series. Guessing my well can handle that it's already handling my current geo unit.

 

From a well drillers perspective. 80% of all our service work is performed on variable speed water pumps. Wanting to test the well is an easy way to ensure that no one is unhappy after you right the big check. If I were you I would lean towards the 5 series and stay with the pumping equipment you have already.
Hope this helps
Eric

 

How long does this pumping equipment last? It's all 17yrs old. Well pump and pressure tank. What size pressure tank should I have to run a 5 series? I want to up my water pressure in house it trickles if you have more then 1 faucet open.

 

If your pump and tank is 17 years old you need to see a technician to:
1. evaluate the performance of your current pump
2. verify the tank and controls are functioning correctly
3. verify the capacity of your current well

With this data you can make good decisions about how to move forward. IMHO pumping equipment that is 17 years old, running geo and domestic, that you are not happy with the domestic performance is crying out for replacement.
Eric

 

I got a couple quotes to test well. 1 was for $100. The other was 95/hr estimating 3hrs.

I turned off well. Emptied pressure tank. And it had like 10psi. I put it up to the 40psi it called for on side of tank. Ton of rust looking crap came out.

 

Did Recharging the storage tank impact your household pressure? That build up of gunk in your tank is typical of a 17 year old system.
Eric

 

Does not seem to lose as much pressure when tub and sink are on. Put overall pressure is only a smidge better. I need to replace the pressure guage in the basement next. Well guy coming next week to test.

 

Just to give you comfort, nothing wrong with the 5 series. I would argue it is the second best geo heat pump out there.

 

One of the installers tried to tell my the 7 series would be better then the 5 series without a variable pump because it had a modulating valve ha

 

That would mean you need a bladder tank (which means your pump is shot cycling continuously), or the pump is pumping continuously with the modulating valve controlling the flow. Essentially that well pump would be working continuously for 4-5 months of winter......or short cycling for 4-5 months. Both costing you at the very least a lot of pumping power.

 

That it why I think I am going to go with the 5 series. $8300 installed w/desuperheater option. I will plumb the tanks in myself saved me about 3k.