Well-water temperature?

[Karl in NY]

I have a new well, northern NY, by canadian border...both neighbors have ~40' deep wells, but my driller didn't hit water until 125', and it turned out to be over 20-gpm and artesian, occasionally rising to over top of casing.

I plan on setting the submersible pump at about 120', and wonder what to expect for water temp. from that depth, and whether there will be any difference, summer vs. winter?

I'm going with a tankless electric water heater, as I don't want propane within the house, although I will use it for a whole-house backup generator.

The question is: if water temp. will be nearly constant, should I insulate the poly-pipe( about a 60' run from well to house) as that line will be buried just below frost line (48"). I'm thinking that the water from 120' will be much warmer in winter than the ground is at 48", and thus insulation could increase the yield of a smaller tankless electric water heater.

No opportunity to test my theory until trench from well to house is already back-filled, then, too late to insulate.

I tried doing searches to determine ground water temp. at those depths, in this climate, without much luck so far.

 

[Cacher_Chick]

My wintertime water temps are around 40 and and my summertime temps are around 50, with the pump set at 100'.

 

[Sponsor]

 

[Craigpump]

52-54 degrees year round here in CT.

I seriously doubt you'd ever see a difference in your energy bill by insulating the water line, but if you do, use 2" pink foam board on top of the pipes before filling the trench.

Fiberglass will offer little to no insulative value when it gets compressed or wet.

 

[Boycedrilling]

Well we test pumped Thursday was 61.5 degrees F. Usually I see water well temperatures from the high 50's to the high 60's. There are some areas 80-90 miles south of me that the temps will run in the 70's and 80's. I've personally only seen it 92 degrees maximum. However there are some areas in south central Oregon that you can see temperatures in the 120 to 160 degree area, at water well depths.

The warmer the water, the more noticeable any tastes or odors are.

 

[Texas Wellman]

Map

https://www.google.com/search?q=wel...D&biw=600&bih=960&dpr=2#imgrc=3PURB_Q8AL04cM:

 

[Karl in NY]

I'm expecting to treat for sulfur and pH, but my first question is whether the poly-pipe run from well to to house being insulated will benefit an electric tankless water heater...I expect that run will significantly cool the water drawn from 120' depth temperature and increase the load on the tankless water heater, during winter months.

Adding thick foam insulation while 60' trench is still open will be be cheap, compared to doing it later, but, I don't know if transit-time in that 60' run
will significantly chill the well water enough to even make a difference, plus, it's not just transit time in that run, but water still in that line between draws to the indoor storage tank that is probably more important, since it will chill-down to about 40° between water usage, and it's a small house with only two regular occupants.

I have Googled this to death, and found zero relevant topics.

 

[Texas Wellman]

The water coming out of the ground should be pretty cold in your neck of the woods. Like 40-50*. I would think that the ground would be fairly cool as well. I wouldn't think the water would gain or lose significant heat on that run either way.