Depth of water sensing 1

[alternety]

I would like to monitor the water depth in well. Maximum depth is 500" and minimum is 0'.

I have been thinking pressure sensor but everything I have found is quite expensive packaged sensors.

Any ideas on other ways to monitor depth or sources of something I can use for a sensor in a 500' well.

 

[wagnerc]

Heck at 5c a kWhr u should build a coil to power the WHOLE WORLD, just like Tesla wanted to do.

This inspires me as to another way to find the well water level. Float a coil on the water level and fire up a huge tesla coil on the surface. From the induced current in the well coil u can calculate how far apart the two coils are.

 

[VEBill]

"Why not just move to a land of palm trees, blue skies and balmy tropical breezes?"

That's in my long term plans since my wife is from a nice quiet, peaceful island in the Philippines.

Getting back on topic, I think it's important to keep the total capital cost of your heating system in-line with the possible savings. In other words, spending tens of thousands of dollars, to save several hundreds, provides a pay back period of several infinities.

Even with my rather modest investment in energy efficiencies and passive solar, I've already reached a point where it barely makes sense to worry about my heating bill any further. My car's gasoline bill is about twice my home heating bill.

 

[14erclimber]

Hi! Am a little hesitant to post much, being a complete neophyte to eng-tips, but might have a useful idea ...

alternety: An interesting problem you have, with the need for a water depth sensor I mean. Very similar to one I'm having with my well. It's a shallow one, by comparison (only 265 ft).

This thread is the reason I found (and joined) eng-tips.com, while looking for a solution for my own well, for which I need to monitor water depth. Long story -- details if they seem pertinent ...

Now before I drag this thread back to the original question, I thought I should ask if you ever got the well depth sensor problem resolved. I haven't read every word posted to this thread, but it kind of appears you still don't have a way to monitor the depth, right? I just thought that before I go into my idea of how to solve it, I thought I'd better be sure it's still a problem (and potentially save a lot of useless typing). I think the sensor idea I came up with would be extendible to that depth, althought some purists might consider it a bit of a kludge. OTOH, the price is right -- really cheap.

Question is, is it stll a problem that needs solving?

 

[alternety]

Welcome to the thread that won't die 14.

I have been seriously crunched on just trying to get the house livable. My probable approach will be to use a power curve I obtained from the pump vendor and only measure while the pump is running.

Based on my success (not!) with getting a well-empty probe down the hole I suspect I should just forget about trying to put anything down there unless I have to pull the pump for some reason (way down on my list of things I would like to have to do). I could of course try a rocket boosted sensor and just blow through whatever got in the way.

I would be interested in your ideas even if I can't implement. I strongly suspect that several others monitoring this thread would also be interested. This place is about ideas. It is an odd form of recreation favored by engineers while others look on and think we should get out more.

 

[VEBill]

Lots of people are interested in sensing the depth of well water. Post away if you have time.


PS: Is the '200 Winner' going to be the 200th post (199th reply), or the 200th reply ?

 

[Warpspeed]

Most definitely interested here too.

 

[wagnerc]

I just had another idea. Set up a small radar unit and aim it down the hole. It should ignore all the junk in the way and give u a good relection off the water surface.

 

[Warpspeed]

How about a six hundred foot long dipstick ?

 

[VEBill]

"...six hundred foot long dipstick..."

Just make a print-out of this 600-foot-long thread onto fan-fold paper and lower it into the well. Then pull it out and find the damp section.


PS: Radar was already mentioned on '27 Jul 05 13:55'. However, well-depth measurement techniques involving use of the solar neutrino flux are all still up for grabs.

 

[alternety]

Status

Yesterday I told the contractor to put a fixed speed pump in and a pressure bypass across the manifold.

We replaced the variable speed pump with a new one (same kind) and nothing changed with the noise. If anything the replacement was a bit noiser.

The distributer for the pump came out and agreed that the noise was too high for residential use. Now the question is whether Grundfoss will take back the pumps. They are almost $1000 each.

I did a little bit of playing around with the pump. I got a newer manual online and found that the speed could be adjusted manually. Even at what should be full speed it makes much noise. This feels wrong if it is the TRIAC causing the problem. At full speed the TRIAC should not be doing anything part way to the cycle.

I would like to find a DC driven replacement with the theory that after I am moved in an get boared I could try PRM on a DC motor with better results. A good PM motor should aldo be more efficient in normal operations.

The pump is designed for about 12.5 GPM at 11 ft of head, 1 1/4" flanges. Anyone know of one. I am looking into one from March.

 

[wagnerc]

I saw some 8 HP Briggs & Stratton motors on eBay that ran on 12 - 48 volts. They were really small for the power, measuring only about 6" diameter. I was thinking about buying some to build an electric car but I haven't won the lottery yet. They cost $399.

 

[Skogsgurra]

Now, someone must be responsible for this. What if said responsible made a summary to keep us less informed guys updated with regard to what this thread is about nowadays? It would also be very nice to know what you have found so far. If possible, make a list of recommended techniques for Depth of Water Sensing - maybe there should be an FAQ on it?

We need this summary before the 200 postings milestone and someone (alternety, wagnerc, smoked, VE1BLL for instance) should feel guilty enough to do it.



Gunnar Englund

http://www.gke.org

 

[wagnerc]

Hey man, don't try to blame me! :-D

 

[VEBill]

Summary:
1) There's a hundred ways to measure the depth of water in a well, but none are perfect.
2) Complicate heating systems are, ah, er, complicated. It's nice to have hobbies.
3) A $30k heating system is a very bad start on trying to save money.
4) Pumps are noisy. Quiet pumps installed perfectly are still noisy.

How's the count?

 

[alternety]

OK very short summary from off the top of my head.

Two best ways to sense water depth:
1 - bubbling tube down the well and monitor pressure at top. Needs air pump to do the bubbling. Air needs to be clean and oil free.

2 - measure pump power draw against manufacturers curve or calibrate the pump yourself if you think you can get something down the hole to find the water level.

A variable speed circulating pump can be used in a hydronic heating system main loop if pressure across the manifolds is the controlling element. It replaces the more common residential approach of running the pump at full speed (even when a very small amount of water is being called for in the operating zone) and bypass excess water from the source to return manifolds using a mechanical pressure relief valve.

A variable speed motor and a pressure sensor are not enough to form a control loop with a setpoint. You have to have a PLC or some such thing to control the system. There are very many PLCs available. You need one with analog in and out with one digital in that can be used to turn the pump on and off when there is heat demend.

The variable speed pump must be quiet. The Grundfoss variable speed pump is too noisy to live with.

I need, I believe, a quiet PM DC motor/pump in the 200 W range and a suitable centrifigual pump to replace the Grundfoss (12.2 GPM @ 10.8 ft of head). If there is a suitable controller with it or I can find a PLC that seems to work (I have looked at a bunch without identifying one) I would stay variable speed. If not, I need the same motor so I can go to variable speed later when I have moved in and have some time.

itsmoked is going for forced air heating.

That is, I think, the high points in the thread.

 

[Skogsgurra]

That is all very well (no pun) and interesting. But the one thing that I remember from this thread is "the sacrifice of a small mammal behind the well head at midnight". It hasn't been mentioned in the otherwise excellent summaries above.

Didn't it work out? And where is Smoked? I am eagerly awaiting his summary. Something tells me that he has a slightly different view than those presented.

Gunnar Englund

http://www.gke.org

 

[wagnerc]

Only 200 watts? I thought u needed a lot more power than that to drive the heating system. There are 300 W DC motors on eBay going in the $25 range. They're Krollman electric scooter motors.

 

[alternety]

Multiple small to medium mammals have not helped. What size range would a contractor be?

 

[VEBill]

Are HVAC contractors mammals?


Count status:
This is Reply #198, thus Posting #199.
Next after this will be Posting #200.
Next after that will be Reply #200.

 

[felixc]

Contractors are usually large mammals. Don't think they will fall down to the bottom of the well, yet they might give you some vocal feedback about the installation while they fall.

What about a 2-speed motor?