Durability and value of solar pumps vs efficient pumps?

[inetdog]

The Grundfos SQ Flex pumps are centrifugal not diaphragm....

Wrong, sir, (although more correct than Oregon Solar.)
The brochure shows that there are both centrifugal pumps (up to ten stage, which can deliver a pretty good head) and positive displacement helical rotor pumps (two or three stage) which can deliver a working head of 800 feet or more.
The 40 GPM models are limited to 50 or 100 foot lift.

Here is the complete type description:

Currently the complete range consists of six centrifugal
pumps and five helical rotor pumps. The centrifugal
pumps are adapted from Grundfos’ present 4” SP
range (16S, 25S, 40S, and 60S). These pumps are
used when lower heads and higher flow rates are
required.
The positive displacement helical pump ends are
3” in diameter and available in five models ranging
from 3 to 11 gpm (0.68 to 2.50 m3/h). These are
designed for higher head and lower flow requirements.
The pump rotor is a single-twisted helix (spiral) made
of hard-chromium plated stainless steel. During
operation, the rotor rotates eccentrically in a double
helical elastic stator.

The smallest of the centrifugal pumps, the 16-SQF-10 is rated at 16GPM and uses a ten stage pump. The pump curves show that it can produce 13 GPM against a 230 foot head, given sufficient input power (1400 Watts, 1.9HP), of course.
The curve family can be extrapolated beyond 230', but apparently operation beyond that range is not recommended.
It can produce its rated 16GPM up to ~190 feet of head.

The largest of the helical rotor pumps, the 11-SQF-2, is rated out to 395', while the three stage 6-SQF-3 is rated out to 820'.

In all cases, the actual GPM will be somewhat lower depending on the piping used, since this head is the combination of static lift and dynamic head from flow friction.

Note: A diaphragm pump is likely to tolerate sand and other abrasive content in the water better than either centrifugal or helical, but the valves will still have problems.

[Naptown]

read the complete data sheet

http://us.grundfos.com/content/gpu/en_US/products/find-product/sqflex/_jcr_content/tabbedpanel/brochures/par2/downloads/download_0/file/file.res/L-SP-TL-014.pdf

[OregonSolar]

look for yourself
http://us.grundfos.com/products/find...ct/sqflex.html

Their brochures say exactly this:

the centrifugal pump (4") for low heads and large
flows

This pump needs to be at least 100 Ft deep. Low head usually means anything <50 Ft. That would be like a shallow well situation. So no, a centrifugal pump probably wouldn't work for this setup.

But otherwise, most AC well pumps are some kind of turbine. I don't really know much past that.

[Naptown]

What depth is that Grundfos pump rated at and at what flow? Personally I think Shurflo's are better,but we all have our opinions

Water column is STATIC at 80Ft, but without looking at the official well log i'll estimate a drawdown of about 30 Ft at 5 GPM, which still leaves it at 110 Ft. You want at least 15-20 feet of water over your pump at dynamic level (pump is running), which will give you a buffer zone for low water years, extended use, etc. where the water will be lower. Also note that when well drillers test wells, they put their test pump at the very bottom of the well and see how much flow the well can sustain for at least an hour, or at least that's the rules here in Oregon.

look for yourself

http://us.grundfos.com/products/find-product/sqflex.html

[OregonSolar]

The Grundfos SQ Flex pumps are centrifugal not diaphragm Not all solar pumps are diaphragm.
If you read his well stats he hit water at 180' well replenishes at 10GPM and the water column came up to 80 feet of the surface.
so even if he put his pump down at the bottom of the well he is only pumping 80' At a typical 5 GPM house flow rate it will not go much below that if at all.

What depth is that Grundfos pump rated at and at what flow? Personally I think Shurflo's are better,but we all have our opinions

Water column is STATIC at 80Ft, but without looking at the official well log i'll estimate a drawdown of about 30 Ft at 5 GPM, which still leaves it at 110 Ft. You want at least 15-20 feet of water over your pump at dynamic level (pump is running), which will give you a buffer zone for low water years, extended use, etc. where the water will be lower. Also note that when well drillers test wells, they put their test pump at the very bottom of the well and see how much flow the well can sustain for at least an hour, or at least that's the rules here in Oregon.

[Naptown]

The Grundfos SQ Flex pumps are centrifugal not diaphragm Not all solar pumps are diaphragm.
If you read his well stats he hit water at 180' well replenishes at 10GPM and the water column came up to 80 feet of the surface.
so even if he put his pump down at the bottom of the well he is only pumping 80' At a typical 5 GPM house flow rate it will not go much below that if at all.

[OregonSolar]

Thanks. The Shurflo 9300 was what I was initially leaning towards. But I am not sure it has the centrifugal technology of Shurflo higher end pumps. My RV pumps definitely do not seem to last very long, but I think they're diaphragm pumps.




Can you recommend a good efficient 120V pump? I do have a small generator (Yamaha 3000) which is good enough to start an AC in the RV with a hard start capacitor.

On the solar side, a good 24V Shurflo submersible that will supply just under 2 GPM (the 9300) runs $700, not counting the $150 controller and at least $300 in solar panels depending on your supplier.



This sort of tank is meant to be buried. I was thinking of a lot less expensive (and easier to transport/stack) variant like this
[ATTACH=CONFIG]3321[/ATTACH]
They go in 275 to 330gal each and can be gotten for low $100's per tote/cistern.

Edit: Upon closer review, the tank you linked to is not meant to be buried. A below ground cistern usually starts around 1,000 (depending on size, etc)

Please excuse my ignorance if anything I ask doesn't make sense. I am here to educate myself.

Don't worry, we're all still learning.

All solar pumps are diaphragm style. It's only a matter of how well they're built. No solar well pump, or any domestic deep well pump for that matter, will use a centrifugal style. Centrifugal styles doesn't have the necessary pressure to push the water up a 200 Ft hole. Even an big 240V deep well pump uses some odd style of turbine that I'm not sure how they operate.

That generator is plenty. I run a 6GPM 120V well pump from 125 feet as a backup for my solar stock water setup from a Honda 3500. Doesn't even load the engine. This 120V pump should do it nicely: http://www.waterpumpsdirect.com/Red-...ump/p7495.html. It's $300 and has a head capacity of 200Ft, so if you don't drop it totally to the bottom of your well you should do fine. Also note even though it says it has a flow of 12GPM, that's at 100Ft, so it should be about 7-8 at 200 Ft, which your well should handle without out-pumping it.

I understand that the tank is not meant to be buried; It was for the type that you were going to put in the house. But you seem to have it down fairly well; just make sure that the tank you chose says it's made out of FDA-approved poly. Probably doesn't matter, but just to be safe.

[NetComrade]

Well, if all you need water for is the house, a solar would probably do it nicely. What do you estimate your demand will be per day? Make sure to calculate all the uses, like toilet flushing (about 1.5 gallons per flush, 6 or 8 times a day depending on the occupants), showers, washing, etc.

By wind-sun.com, I assume you mean Northern Arizona Wind & Sun? They are VERY wrong. I have a solar stock watering system using a 9300 pump and it's been going for the last 5 years. Unless it's a cheap chinese knock-off, expect a lifetime of about 6-8+ years out of the Shurflo pumps. I'm not spending $500 on a 2-year pump. the Grundfos might be OK, but I recommend a Shurflo.

Thanks. The Shurflo 9300 was what I was initially leaning towards. But I am not sure it has the centrifugal technology of Shurflo higher end pumps. My RV pumps definitely do not seem to last very long, but I think they're diaphragm pumps.

But, main question: Do you have Grid power, or do you use a generator+solar banks? if you have access to grid power, why are you even considering putting in a solar well pump? Buying a good 120V well pump that delivers about 6 Gallons Per Minute at that depth will run you about 300$ and last at least 10 years if not longer. Some have even lasted 30 years. And you can grow a lawn or a garden with it.

Can you recommend a good efficient 120V pump? I do have a small generator (Yamaha 3000) which is good enough to start an AC in the RV with a hard start capacitor.

On the solar side, a good 24V Shurflo submersible that will supply just under 2 GPM (the 9300) runs $700, not counting the $150 controller and at least $300 in solar panels depending on your supplier.

Then, on to the tanks. I really don't have that much experience in tank storage, and I'm not sure how to properly sanitize them, so you should do some more researching that aspect. but I did see this when poking around: http://www.plastic-mart.com/product/...FUlyQgodFkIArw I assume that this is the kind of tank you were planning on using? How are you going to get it in the basement?

This sort of tank is meant to be buried. I was thinking of a lot less expensive (and easier to transport/stack) variant like this
2_totes.jpg
They go in 275 to 330gal each and can be gotten for low $100's per tote/cistern.

Edit: Upon closer review, the tank you linked to is not meant to be buried. A below ground cistern usually starts around 1,000 (depending on size, etc)

Please excuse my ignorance if anything I ask doesn't make sense. I am here to educate myself.

[NetComrade]

This cabin is in a remote area with a good probability of power being down for a day or two.
The house is getting connected to electric this week.
Based on my water bills, the usage is about 500 gallons per day (worst period based on my water bills). This actually sounds high for a 2 person household.

I think in no power situation we should definitely be able to get it under 100.

We are currently getting by in an RV on 35-50 gallons through the weekend, but I realize water usage profile would be higher in a house even if we tried to conserve.

What I was trying to figure out if solar is worth it. It sounds like if you have power it's not really worth the expense.

The person that I plan on working on on solar side recommended that I go with an efficient variable frequency 240V drive like Pentek Intellidrive (he claimed they're around $600). I think it uses less electricity, requires a thinner wire, and has the minimum startup demand.

When I asked him about 220 (or whatever it is in the 200's) vs 110-115, he said that current inverter technology allows to go to 240V relatively inexpensively.

[OregonSolar]

Well, if all you need water for is the house, a solar would probably do it nicely. What do you estimate your demand will be per day? Make sure to calculate all the uses, like toilet flushing (about 1.5 gallons per flush, 6 or 8 times a day depending on the occupants), showers, washing, etc.

By wind-sun.com, I assume you mean Northern Arizona Wind & Sun? They are VERY wrong. I have a solar stock watering system using a 9300 pump and it's been going for the last 5 years. Unless it's a cheap chinese knock-off, expect a lifetime of about 6-8+ years out of the Shurflo pumps. I'm not spending $500 on a 2-year pump. the Grundfos might be OK, but I recommend a Shurflo.

But, main question: Do you have Grid power, or do you use a generator+solar banks? if you have access to grid power, why are you even considering putting in a solar well pump? Buying a good 120V well pump that delivers about 6 Gallons Per Minute at that depth will run you about 300$ and last at least 10 years if not longer. Some have even lasted 30 years. And you can grow a lawn or a garden with it.

On the solar side, a good 24V Shurflo submersible that will supply just under 2 GPM (the 9300) runs $700, not counting the $150 controller and at least $300 in solar panels depending on your supplier.

Then, on to the tanks. I really don't have that much experience in tank storage, and I'm not sure how to properly sanitize them, so you should do some more researching that aspect. but I did see this when poking around: http://www.plastic-mart.com/product/...FUlyQgodFkIArw I assume that this is the kind of tank you were planning on using? How are you going to get it in the basement?

Long story short, solar ain't worth it if you have grid power. Even then, if you only have a generator you can fill your tanks while it's going with the 120V pump. If you're 30 miles over the hill from the middle of nowhere, solar is the otherwise only option.

[Naptown]

Not enough info on storage to determine anything
The pump is a no brainer
The Grundfos is a better value
Particularly if you are paying someone to replace it every 2 years vs doing it yourself

[NetComrade]

Dear Forum, I am in the process of building a weekend cabin.
The well has already been dug, the well stats are
10GPM
220 Feet
Hit water at 180
Water Came up to 80 feet.

We are on a high bank of a river, and the well is no more than 100 feet above it.
The well is bored about 50 feet away from the dwelling.
The cabin has about 30 feet of height (basement, first floor, 2nd floor)

I reached out to wind-sun.com for solar pump recommendations, and they recommended one of their low-end sunpumps.
The quote is for ~1500, but they also brought up that these need to be replaced every 2 years (at 500 each, plus installation time/money)
The Grundfos pumps apparently last 10 years, but are 2-3x more expensive
On top you need water storage, a compression canister and booster pump.

So question is, is solar pump worth it? (I don't have a quote for a regular 220v pump yet)
Do they have similar durability/logevity as regular 220v inefficient pumps?
Can one consider a 110V efficient pump?

If solar pump is worth it, how can you improve it's value?
For example, can you use the 300gal totes and keep them in the basement for water storage, instead of an inground insulated storage tanks that run for 1500-2000 each in just materials.

Thanks!