any heating/cooling engineers here?

[Tiamat]

interesting.

You will probably need a good pump to get the water moving fast enough that freezing in the pipes would not be an issue.

are you going to have a tortuous path way? or just a more simple array of parallel pipes going down the driveway.

You will need massive flow rates, probably something like the total flow of a fire hydrant when openned up.

At the minimum you should perform an heat transfer analysis between the concrete and water and tube. It will be similar to an example of a pipe with insulation wrapped around it. Text books will have the k values you need, and at the moment, you have the inside temperature (water), so you can calculate the interface temperatures and finally the temperature of the concrete (make up ID of pipe) to see if this would even work.

You may find that the power required for the pump(s) severely dwarfs the power required to electrically heat the driveway.

 

[shilala]

Aside from not providing enough heat to melt the snowload, this idea would involve pumping water 24/7 during the winter months, or the whole shytsmear will freeze up, rendering it useless.
A good use for the neverending water would be in a heatpump application.
But, if you insist...
I think the best move would be to create a closed loop glycol system under the driveway, that way you'll protect your investment and if things don't work out, you'll still have a usable system that you can add to a boiler. Use a simple heat exchanger to transfer the heat from your source water to the driveway loop.
That'll add another pump and a heat exchanger to your system, but you'll only need to protect your piping to/from your source from freezing.
This strategy should protect you from the freezing problems.
I'm afraid to calculate how much tubing or copper you'll need under the driveway in order to transfer the btu's you'll need to handle the load. The low water temp is a major bitch. The cost of the added tubing isprobably going to be the deal breaker.
If it doesn't work, at least it was fun.

 

[echo4747]

Originally posted by: Dubb

Originally posted by: echo4747

Dubb.. From what I've been told this ground water that my well taps into must be from some sort of underground river. My house is located near the top of a hill .. when I go down the street about 1/4mile at the base of this hill where the next street intersects, there is a grate with about a 12-14 inch dia pipe with water constantly rushing out of it. A friend and i dropped a few tablets of a red plumbers tracing dye into my well casing .. went down to the end of the street and saw the presence of the dye in the aforementioned grate/storm sewer. There have been times that it hasn't rained for 10-14 days and water still rushes out. Funny thing is several of my surrounding neighbors wells run dry after pumping for 5 min. My well never goes dry as well the neighbor directly across from me. My well is only 21ft deep his is 40ft deep.
Dubb .. what is exactly the purpose/use of the evacuated tube?

so the city connected the underground river to the storm sewer? Interesting to say the least, have you checked with the city to see what info they have on it? as you know that's one hell of a resource for summer cooling.

Just got off the phone with the town engineers office. The engineer was very familiar with the storm grate. He says it is part of the storm sewer system. He also mentioned that the waters been flowing thru it day in /day out for many years. He says it from a spring. I do know for a fact that this water source( whether its a spring or underground stream/river) is part of the same source that my well draws water from ( dye testing confirms this)

Anyway, I think the advice/comments from those who have contributed to this thread are probably right . A closed loop system is probably a better/wiser choice unless I can make sure I can pump a greater volume of water than I currently can.