Geothermal loop

[enderg60]

Dave, you will want to use RO water and about 10% antifreeze. Its either that or straight alc. Well you are in the boonies, just get your neighbor to make you a few gallons of moonshine

You dont need a flow meter, just hook the system up and time it into a bucket. Once you get the initial flow your done.

yes get two temp sensors, one in one out of the Ti exchanger. This will tell you the incoming temp of the water and if its getting heat soaked over time, and how much heat your removing from the tank. Using that info and the flow speed I can tell you exactly how many BTU/h of heat it is removing.

you will also want a resivour tank that isthe high point of the system to add coolant to and monitor if there is a leak in the system.

 

[jonathan]

Wouldn't it work more efficiently if you pushed the actual tank water through the buried coil and back to the sump?

 

[enderg60]

Yes but then you run into issues of stagnent water in the pipes when its not running, crap getting into the tank water if the pipe cracks and so on.

 

[grouper therapy]

Why the antifreeze?

 

[enderg60]

it keeps stuff from growing in the water which could clog the system.

 

[jcusmarine]

Tagging along. Very interesting.

 

[mojo]

EnderG60;364714 wrote: Dave, you will want to use RO water and about 10% antifreeze.

Ender - you probably are already aware of this, but just in case grouper isn't... there's a particular antifreeze for use for geothermal systems that's eco-friendly. If the underground pipe gets a crack in it, you don't want antifreeze seeping into the water system...

 

[grouper therapy]

mojo;365081 wrote: Ender - you probably are already aware of this, but just in case grouper isn't... there's a particular antifreeze for use for geothermal systems that's eco-friendly. If the underground pipe gets a crack in it, you don't want antifreeze seeping into the water system...

good info I will most surely use it going to search it now Thanks

 

[savingnemo754]

I have been doing some research for a home system and for a horizonal loop you can dig a 24" wide ditch 8' deep. Place a tube on either side of the ditch and cover with 2' of dirt, then loop tubes back and cover. So with one 2' wide ditch 300' long you could have enough of a loop to equal a 2 ton ac unit.

 

[jackthereefer]

mojo;365081 wrote: Ender - you probably are already aware of this, but just in case grouper isn't... there's a particular antifreeze for use for geothermal systems that's eco-friendly. If the underground pipe gets a crack in it, you don't want antifreeze seeping into the water system...

You probably also will want to consider what would happen if the leak occurs in the heat exchanger, and it leaks into the tank...kinda wonder if saltwater in the closed loop system would solve the freezing issue (if that's a concern)...

 

[grouper therapy]

JackTheReefer;367313 wrote: You probably also will want to consider what would happen if the leak occurs in the heat exchanger, and it leaks into the tank...kinda wonder if saltwater in the closed loop system would solve the freezing issue (if that's a concern)...

The chances of the titanium heat exchanger leaking is far less likely than a 200 lf of pipe buried underground. Freezing was not the reason for the antifreezw.Ender suggested it to cut down on bacterial growth within the loop. Saltwater would not stop the freezing if that were the issue since saltwater will freeze anyway.

This will be a closed loop system . I have considered the running of saltwater thru the loop but for all the reasons already stated I chose to use the heatexchanger with the closed loop. I would really like to keep the thread headed in the direction of the closed loop system and gather ideas from you guys accordingly. I hope everyone understands.

 

[cdub]

Instead of anti freeze why not vinegar or something else that will raise/lower the ph enough to prevent algae growth. Plus it won't nuke the tank if the exchanger leaks.

 

[grouper therapy]

cdub;368326 wrote: Instead of anti freeze why not vinegar or something else that will raise/lower the ph enough to prevent algae growth. Plus it won't nuke the tank if the exchanger leaks.

Interesting I will have to consider that. I also will have valves to drain and refill fairly easily the loop so that I can maintain it. With no light getting to it I wonder how much of an issue algae will be?

 

[grouper therapy]

JackTheReefer;367313 wrote: You probably also will want to consider what would happen if the leak occurs in the heat exchanger, and it leaks into the tank...kinda wonder if saltwater in the closed loop system would solve the freezing issue (if that's a concern)...

That is something to think about. The leaking of the exchanger . I think it is highly unlikely but possible. Good food for thought. Thanks.

 

[grouper therapy]

Finally gonna plumb in the loop tomorrow will post some pics

 

[skriz]

Can't wait to see this..awesome!

 

[chymos45]

Care to enlighten us on the plan of action? How deep to bury, schedule 40 vs. 80, what fluid media, etc. I thought about doing the same thing about a year and a half ago, but chickened out. Really interested to hear how this turns out.

 

[grouper therapy]

I buried 200 lf of thin wall pvc(schedule20 or22 I think its called) at 5' . I am startng the system with tap water and will convert over to some type of mixture containing an antifreeze. I am plumbing a venturi into the system to inject anti fowling agent of some type. I took a scrap 1hp chiller and stripped the compressor and condensor away. Now I have a chiller barrel, fan, and control unit left. I will mount the unit at the end of my sump so that the fan will aid in cooling with evaporation. The temp. control unit will control the circulation pump of the loop. The actual tank water will run through the barrel(heat exchanger) constantly. I am also plumbing a supply line and a purge valve so that I can change the water out of the line from time to time and perform maintenance . It will serve as an air bleed off as well. Got to go do it now.

 

[chymos45]

Well, log off and get to it! Don't forget the camera!

 

[enderg60]

dont forget the temp sensors ports so we can size the system