Pretty Cheap House Cooling?
 

So a year or two ago I tried something simple to see if it worked, I put a sump pump out in the creek in my back yard. Hooked a water hose to it and ran it through a window in my house that attached to an old car radiator. Then ran the other end of the radiator back out to the creek. With a normal box fan on the radiator it could cool my house down almost as good as the window a/c I have. I used it for a week or two but ran over the hose with a lawnmower and never bothered to fix it.

So I am thinking now that I acquired a new toy
http://rthompson.us/temp/kubota.jpg
I am wanting to redo this system but make it a bit more permanent and better working. The plan is to dig a really big hole in the yard at least 6ft deep so it is below the water table in my yard and put a large tank of some sort in the ground. I am thinking of a 500 gallon tank. I can fill the tank with water and it will pretty much stay at ground temp of 55 degrees F. From there I can pump the water through a car radiator/fan setup in the house somewhere and cool the house with very little electric required.

a 3/4" pipe should be more than big enough for the amount of flow I figure and a small pump is all that will be needed since there will be no lifting of the water, just pumping it closed loop. All of that is just a wild guess but it seems like it should work. If it does work it would be really cheap to keep the house nice and cool all summer. The house is 25'x40' with 7ft high ceilings and no insulation at all, just some blow in insulation added to the attic. If anyone has any experience with something like this and would know of what size tank and flow I actually need let me know.

I could insulate the house but it costs me like $300 a winter to heat it so it really isn't worth the trouble. If this works I have some strange ideas to try for solar heating :)

Sounds like basically a DIY ground source heat pump on the cheap. Sounds reasonable enough. Is your tank going to have an open bottom to basically use like a well? Otherwise, I would worry that it might actually insulate the return from the ground too much.

I was thinking of instead of using it like a well just put a sealed tank below the water line so it was always wet on the outside. It seems like it should be able to conduct enough heat through it to keep cool. I could be wrong though :)

The way the temperatures are here normally if I want to run a/c I normally turn it on at 12-1 and run it till about 5 or 6. There are enough trees around the house to keep it tolerable without a/c and just open windows with fans in them. I haven't turned on the a/c this year actually. Mainly because I haven't been in the house during the day so the fans keep it good enough. I figure 4 20" box fans are probably taking the same amount of power as one box fan and a small water pump but the house would be much cooler with the ground based setup.

If you're talking about a metal tank, you're probably right, but I assumed you were planning on a plastic tank. It might be a good idea to do some testing before you go to all the trouble of installing this big tank in the ground. I'm just afraid the amount of heat removed from the house is going to be more the the ground can remove from your water and then your efficiency goes down the tubes. In commercial systems they use the compressor to increase the temperature differential between the medium (water in your case, but they usually us some sort of antifreeze) and the ground, but that's so they don't have to use a reservoir like you're doing.

Good luck.

Ha... i have a car rad in the back of my car right now that I was going to run cold water through to cool my living room. It seems like a good plan. You say the creek was feeding your system well? What if you just buried an open-topped box in the creek with 3-4 parallel car rads and make it a closed system?? If it works well, add some antifreeze or "Water Wetter" to the system to improve its heat transfer ability. This is brilliant, by the way, kudos.

We have a Sanyo Tri-Zone A/C unit. Does a very good job. Our cooling costs are cheap. It's our heating costs that are up there. Our winter power bills are usually about 4-6 times our summer power bills.

But I do like your creek water cooling system.

I'd re-think the insulation. Since I got the attic insulated, I can open windows at night and cool the place down, then close them in the morning, and even on a 100 degree day it will stay below 70 until 5 or so. Of course this is in northern Nevada, where it usually drops below 60 at night even on the hottest days. May not do as well in more humid areas. But even so, your ground-source A/C wouldn't have to work nearly as hard.

The creek is not very consistent. Right now it is at best an inch deep and a foot or two wide. Sometimes after a heavy rain it is 5ft deep and a lot of silt and mud in it. So anything I put in the creek will either get washed away over time or be buried in silt from the strip mines. The system I put together before was I think a 1/4hp sump pump running to a good size garden hose and the exit from the radiator('75 dodge polara) was also the same size garden hose running back down to the creek to keep the pump from having to lift the water as high. I figure the pump was putting out a lot more flow than it needed but it was just stuff I already had so it got put to use. If someone had a more consistent stream near their house a coil of copper pipe or old radiator put in the stream could probably be used to transfer the heat using a closed system and be pretty reliable. I did it mainly just to see if it would actually work, I was bored and had nothing better to do than mess around and build things. This summer I am just looking for excuses to play with the tractor :p

I asked a few people today and one guy says he could get me a used 10,000 gallon tank for free if I come get it. No idea how I would haul it in a Metro and the little Kubota tractor I have would take 6 months to dig a hole that size. But I did manage to find a potentially endless supply of 55 gallon barrels for free :) So now the plan is dig a ditch wide enough for the barrels and keep them about 3ft apart and run the water through them in series. I have no idea how many barrels I need but I might get a few of them and bury them to run an experiment. I could probably dig a hole and put 2 barrels in the ground and hook up a working system in a day without a lot of effort. The two barrels would give me a better idea of how much heat each one could handle so I know how many actually need to be used. Then I could get that many plus a few extras and hook up a more permanent system.

I don't actually think this would save me much money in the short term though. My electric bills are pretty much always $35 a month since I haven't used a/c this year, ~$100 with heavy a/c use. I am just not in the house during the day to care how hot it is in here. Winter my gas bills max out at around $90 so really it doesn't cost much to just keep doing what I am doing now.

NOW there is a good heat transfer.

If you got a heat pump window unit and encased the condenser (outside cooling fins) in water pumped through these barrels then you would have an excellent heater as well as a very cool/ efficient A/C. Just wire the pump on a contact or with the compressor. if the system is closed you can get away with a very small pump.

Pretty impressive, CoyoteX. I've always wondered if I could do that with my well.

Are you having any issues with condensed water?

hmmm using well water may be a idea , just return the water to the well.. any one heard of doing this at all?

little googling gave me this...
Cheap: How to Get Free Air Conditioning From Your Water System

that is interesting....
what part of wv u from?

diverting water before it goes to the hot water tank, toilet, etc is a good idea. Basically any place that does not require COLD water could have its supply diverted to a rad first. The kitchen tap is the only place that I can think of that i'd use COLD water from without turning on the hot tap a little.

How about a weave of large diameter tubing spread throughout your yard underground? As the water flows, the greater surface area of contact between the tubing and the outside would be more efficient in heat transfer. You can use whatever you want without the worry of freezing as long as it's buried below the frost line. Be sure to insulate anything above the frost line and in the air.

If that is the case...get them all...use what you need to experiment on your system...then take the rest of the endless supply to a metal recycler...and make some extra money.

In omaha scrap metal is selling for about 190 a ton.

I'd be worried about the tank leaking -- how about a boatload of tubing in layers in a long skinny trench?

How can you incorporate a cheap windmill and solar reflector into this?

We don't get wind here :( I think the record for the town is 50mph wind. Normally the wind is maybe 1-2mph at best and before a storm we might get 5-10mph wind.

I don't really have a plan for when a barrel gets old enough to leak but I figure I can get an easy 5-10 years out of them if I make sure they are coated well with undercoating or something else similar.

But before I can do any of it I have to get caught up on all the other random work that needs done around here. Really I probably won't get started trying this out till spring.

Awesome Idea. . .
 

I was looking at your thread and now I am picking up a rad (Im going to use the well system Idea and don't want to contaminate it). I'm thinking that I will hook the rad to my cold water hose from my washer, with a y garden hose, and then have the rad in front of my furnace and just have the blower hose going. It will probably take some time to get it cool in here but once it does it shouldn't be a problem

Just be careful with condensing when you build these systems.

My tap water is well below +10C, pipes run in bathroom and at summer those pipes are often rather wet when I run water, air temperature is higher and can contain more humidity than surface of pipes where temperature is lot less, so water condenses to that cold surface from the indoor air.

This might sound a little, but when pipes constantly are cool it can amount a lot water during 24hours and water is not good at wrong places in the house. Some insulation that is not letting humidity enter to insulation and pipe surface, would solve that and naturally improve efficiency of the system.

Old radiators have had coolant in them probably, here we use Glyckol/water mix of 50/50, your area may wary, but I would be cautious of running water through radiator, some closed loop heat exhanger made from simple bucket and copper spiral might be already better to stay safe side.

Just some random thoughts that came up while reading this stuff.

Table fan, carbdboard + duct tape might be also nice way to get air moving trough radiator with low cost and ok efficiency, also put fan to such air from radiator for lower noise and greater efficiency, that is what I learned when playing with PC water cooling, there I had car heater matrix that I used to cool cooling liquid for pc, system is really similar to this, only that it used metal block to cool cpu and gpu, with house cooling scale is just bigger and block is replaced with cool water source, it does not matter if it is heat or cold that is radiated, only with cold one need to be careful with humidity and condencing, which also comes to play with computer cooling when you go extreme.

Anyway, guys doing water cooling systems by themselves know quite a bit about air and water flow and some even know how to deal with condensing issues too, one just need to scale that up a bit.

4-5C increase in house temperatures when I use my current air cooled pc, boy have I thought about setting up water cooling and to went that heat outside to keep house temps down, at winter of course another radiator to warm the house, cooling is not necessary here, temps are still below +20C daytime, even there was three days with temps bit higher, even up to +24C one day, but less than 10 days this summer when temperature has been above +20C.

Anyway, copper coil to fireplace and transferring heat with such setup to upstairs is something I have been thinking, again lot of similar things applies as with cooling, radiator with fan is so much better transferring heat compared to those normal no fan models that are used in houses.

There is a house down the street that has a closed loop of PEX pipe coiled around the house below the frost line, the radiator from that is on the incoming fresh air from the air to air heat exchanger, the house is super insulated and it takes care of 100% of their cooling needs in the summer and preheats incoming fresh air in the winter.
Because it's a closed loop there is very little resistance other then that of the pipe for the pump to push, no head like you would have with a well, so it takes very little energy to keep the system going.

as I recall , the underground house book circa 1970s says build a 12inx12in tunnel 100 ft long below the frost line and pull the house air through it,that should cool a 1000 sq ft home to 57* winter preheat or summer cooling you can use the same 20in fan and save all the complication of radiators and water,tubing etc. . It may be a good use for your new toybota

The big issue that people have had with earth tubes like that is rodents, insects, mold, mildew and radon, you end up with a lot of basement like surface area that you are pulling air from while a radiator is very easy to keep clean and you don't have to worry as much about rodents moving in or a heavy rain storm causing it to fill up with water.

We just dug a trench for electricity. Would have to agree that it would take a heck of a trench to dig a big loop outside the house for air transfer. It would be a monumental undertaking. Big expensive conduit.

I am sure that even if were sealed it would house all sorts of nasties after a few years. Bugs, rodents, mold and other filth that would be recycled. and impossible to clean out. Even a small leak allowing moisture in would likely bring in water which would compound the problem.

I like the original idea of pumping cool water through a radiator. It would still eventually clog up.

Nice tractor and Yamaha btw.

Why not put a little anti freeze, or similar in it?

While these cooling systems don't come cheap, putting them in place when the foundations are done, means the digging won't take very long when using a backhoe.

The air can be filtered at the intake, so the critters can't get in.