Technically it should be called a heat exchanger, we lovingly call it the water cooler, but it has been providing us with free cold air for more than 20 years now so it definitely does work.
Shortly after moving here (Montana) I noticed that the water from our well is really cold, under 50 degrees. I built this heat exchanger to take advantage of that cold source for use in the house in the summer and as a byproduct it heats up the water going to the garden a bit before it goes on the plants since the plants didn't seem to care to much for the super cold water. Good benefits all the way around and since I would be pumping the water to water outside anyway the only actual cost is the power to run the box fan that moves the air through the copper piping.
How well does it work? We hit a high temperature in July of 112F, hottest that I can remember. The temperature inside was 76F with the cooler running all the time. I almost didn't want to go out to move the sprinkler.
The disadvantages? Well, you have to move the sprinkler a lot, but it does keep the grass green. Also if the humidity gets high, water will condense on the exchanger the same as on a glass of cold water. So I keep towels underneath it to soak up the moisture. If it gets really muggy I have to change the towels several times a day. I just hang the wet set outside in the heat to dry and rotate the dry ones back under the cooler.
It will take some skill to put it together but once done it is maintenance free, except for the time I left it outside before putting it away for the winter and it froze some leftover water in a pipe and broke it. Make sure to get the water out of it and store it where its above freezing.
Another disadvantage, it isn't pretty, but it is unique and truly "green".
Shortly after moving here (Montana) I noticed that the water from our well is really cold, under 50 degrees. I built this heat exchanger to take advantage of that cold source for use in the house in the summer and as a byproduct it heats up the water going to the garden a bit before it goes on the plants since the plants didn't seem to care to much for the super cold water. Good benefits all the way around and since I would be pumping the water to water outside anyway the only actual cost is the power to run the box fan that moves the air through the copper piping.
How well does it work? We hit a high temperature in July of 112F, hottest that I can remember. The temperature inside was 76F with the cooler running all the time. I almost didn't want to go out to move the sprinkler.
The disadvantages? Well, you have to move the sprinkler a lot, but it does keep the grass green. Also if the humidity gets high, water will condense on the exchanger the same as on a glass of cold water. So I keep towels underneath it to soak up the moisture. If it gets really muggy I have to change the towels several times a day. I just hang the wet set outside in the heat to dry and rotate the dry ones back under the cooler.
It will take some skill to put it together but once done it is maintenance free, except for the time I left it outside before putting it away for the winter and it froze some leftover water in a pipe and broke it. Make sure to get the water out of it and store it where its above freezing.
Another disadvantage, it isn't pretty, but it is unique and truly "green".
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Signing UpStep 1: Check your water temp
For this to work at all you need to have cold incoming water. The colder the better. Get a standard waterproof thermometer and run your outside water for a while and find out what temp it is. This probably will not work in places where you have a municipal water supply unless its from a cold source. Also you need to have enough ground to water so you don't water log your garden and lawn. It will probably work best in rural areas.
With the fan turned off and the water running outside the temp of my copper pipe is 48F (Infrared non contact thermometer reading)
With the fan turned off and the water running outside the temp of my copper pipe is 48F (Infrared non contact thermometer reading)
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awesome!
regards!
Samad Haque
I would think that the more efficient air handler with a blower would enable you to do the same thing using less water..
Awesome project!
Thanks!
There is about 150 feet of hose between the outlet and the garden. The water does get warmer just from the air while flowing through the hose. I have never checked the temperature at the garden end. The water is still cold, but not the bone chilling temperature that it is coming straight from the well.
If your water starts at 50F and you lose at most 15deg in the process, you should still be well under ambient temps and be able to reuse the same water (granted, at lower efficiency).
Times when you are only using 1 sprinkler and therefore have low flow you could have a recycle valve to loop the same water through several times before it is ultimately used.
Have you thought of/ experiment with this? It's hard to guess how effective it would be as there are so many variables, but it seems solid on paper
There is also another factor involved and that is the more pipe you add the greater the resistance to the water flow so you drop the outside water pressure and flow amount. And of course the more pipe, the greater the chance of a leak.
This may be changing in the next few years though. For almost 15 years they (federal, state and local and tribal) have been working on a rural water system. Because of the poor quality ground water (it's high in alkali and iron) it was proposed and accepted to set set up an entire water system complete with a many million dollar filter plant that will use Missouri river water. They now are close to finishing the plant and are putting in the main delivery trunk lines. It is a huge project and the mains will run about 175 miles end to end. I am supposed to linked up to it eventually (we have joked, if we live long enough). At that time I don't know whether I will keep my well running. I will have to see what the water temp will be. They are also supposed to add outside spigots for watering, but again its a wait and see thing.
I would use the domestic supply for drinking, cooking, bathing, laundry, etc.
But CONTINUE YOUR WELL OPERATION for a few reasons:
1. In the event of failure of the domestic municipal system your well would be a good emergency back up.
2. In our area [SE Texas} a disused well will "silt in" and become totally unusable, AND COST A SMALL FORTUNE to have it "redrilled."
3. In Texas, due to deteriorating underground aguafer water availability, there is talk of a "freeze" on the installation of any new wells, which means that only those with existing wells will be able to use the underground aquafer water, and thus be FORCED to use the EXPENSIVE TREATED municipal water source(s). So since you have the well established, I would keep it operational.
Because of all the rain and snow this year our water table has actually gone up. Not the norm but good to know for us. My sister did some research and she found that last time there was a weather pattern like this for the north and the south was in 1956 when Oklahoma set new heat records. Hopefully your area will return to normal precip and help the water table there.
They are spending a lot of money to put in this water system but I don't know that I will trust it for a while. This area has had a lot of water main problems in the cities. A rural one I think might have similar problems. Keeping a water main down far enough underground to prevent freezing causes all kinds of issues with shifting and such. So yes I will keep my well going.
After going on the municipal system for your potable water, CONTINUE to maintain your well and cooling system, AND also use it for ALL IRRIGATION [lawn, garden, etc.] as that will be MUCH LESS EXPENSIVE, and will not tax [overload] your municipal, potable water system. This protection of the capacity of a municipal potable water system is CRITICAL in periods of draught, when most municipalities enact ordinances to RESTRICT water use so they can keep up with damand so that EVERYONE can have potable water.
The coldest water (incoming) is the last one the air goes through. I have tried reversing it but I didn't notice that much difference. But it just makes sense that the air goes over the coldest metal last. A bigger puzzle is if it makes much of a difference what the fan speed is. One would think that the slower the air speed the colder the air would get but on the low setting it doesn't appear to move enough air to cool very well. On medium only the room its in gets cooled while on high it pushes the cold air into the other rooms. I could probably engineer it better and get more efficiency but I think the gains would not be that great. It does what I need in its current form so I have been happy with that. I might change it around in the future but for now its good.
I initially had only one layer of exchangers, that didn't work as good. Adding the other 2 layers helped a lot. I thought about adding a forth but if I do that then it will become difficult to move. I would almost have to make it in sections. So again I am opting for simplicity rather than super efficiency.
So, yes, I think your suggestion of "counter-flow" would be the better approach.
Then preheat the entire section uniformly [requires practice and developed skill] and then when preheated, quickly apply the solder to sweat each joint "almost" simultaneously.
Again, this proces is like walking what in the circus is called a "slack rope," which is difficult but not impossible.
Since it is NOT an acid based flux, I use it for all my electrical and electronic soldering also.
ALSO, the less humidity in the interior air, the "cooler" one will feel because the lower humidity will enhance the evaporation of body moisture [persperation/sweat] which occurs ALL THE TIME, regardles of ambient temperature, especially in summer, but even in the winter.
Fairly significant, since an 80W panel is quite large.
Nice thing is, you won't need to run it unless it's quite sunny.
How about Solar Cell->well pump->radiator->elevated holding tank
Then drain the tank back into the well at night.
This way you can keep it running, without worrying about running your well dry.