11,000 BTU DX GEO Heating
 

Howdy again, as some of you know I have a few projects that are still in the design stage, mainly due to money issues and an unsure time frame of a off grid dream.
This build is not limited by either one. And will help give me real data for the 4 ton DX system if I do ever decide to go through with it.

The Plan:
My greenhouse is 24 feet by 16 feet, and is built onto the front of my house so only 42 feet of liner wall space, 7-8 feet high, is triple walled 8mm poly panels. Same for the roof. I heated it with wood last year but I hate having 2 fires going plus I would like to heat my fish tank water in the aquaponics system.
The Idea:
The 17 feet deep 2-3 acre pond is 75 feet from the greenhouse. I want to run a loop of 300 feet (total 150' to and 150' back) of 1/4 or 3/8 copper into the pond. 75 feet of which will be buried 6-7 feet deep all the way to the pond, then the rest will be sunk 6 inches from the bottom of the pond.
I have a spare 6,500btu rotary window unit that I will be harvesting the compressor and evap coil/fan from. Here is where it get tricky. I want to put in a 3 way valve setup on a thermostat that is in the fish tank. It will bypass the evap coil to a non copper coil (copper bad for the fishes) in the fish tank.
Parts Needed:
Compressor I already have
Evap and fan I already have.
Thermostat I already have
300 feet of either 1/4 inch or 3/8 copper tubbing. (ideas? I thinking 1/4 should be ok, but that is a lot of resistance for a 6,500 compressor.)
Oil separator, Jeff5may, you posted a picture of a small oil separator in the 4ton thread, I'm having the worse luck finding one small enough for half ton. Do you happen to know where that image came from? Or does anyone know where to find one? I know they are used on extreme computer chillers but have been unable to find where they get them, because most are not built in the states. I found this one Q E HVAC R Refrigeration Oil Separator 1 2" ODS New | eBay but I know its too big and will probably not cycle the oil back at the right time/volume for a small compressor.
3 way valve. I'm thinking this will be fine, Ranco V3 310081 7GD B1227308 3 Way 1 2 Ton Reversing Valve 10283 | eBay

I will start building just as soon as parts arrive, I'm tired of keeping two fires going in the winter.

Thanks guys!

You can use a bullet strainer as an oil separator. Supco no. SUD 115 is the common one. Two Tubes facing up, single tube facing down. Bottom tube feeds long, small diameter cap tube back to suction line.

Jeff, Thanks I'm looking into that right now. I know I should have ordered more of those. I just used my last one. I can't seem to find this application of the SUD115 anywhere. Makes total sense though. Would 2 of them back to back be safer?

Shopping list.
Stainless steel coil for the aquaponics heat exchanger http://www.ebay.com/itm/304-304L-Sta...-/290552612112

45% Silver braze to braze the copper to the stainless http://www.ebay.com/itm/98102-Lucas-...item2357e81a0a

SUD 115 Modified drier/ Oil Separator http://www.ebay.com/itm/Copper-Liqui...item3f4eb94254

3 way valve http://www.ebay.com/itm/RANCO-V3-310...item3378ddafdf

I'm getting the 300 feet of 3/8 copper locally because its much cheaper that way. And I know what I'm getting.

Here's a good article on oil separation:Oil management in a refrigeration system - Carly : the international expert in refrigeration components

http://www.carly-sa.com/IMG/Image/Se...agement_gb.png
If you use the service valve for your gas outlet, you can flare your stainless line and save some trouble.

Jeff, again awesome info. Seriously if you are ever in Oxford, look me up. I owe you a beer, and solar cooked organic homemade meal. ;)
Just added this to this list of parts needed BC49X11 Supco Capillary Cap Tube 049 ID x 11 ft Series for Refrigerators AC | eBay

Sadly I will have to come out of the oil separator to a 3 way valve THEN into the stainless steel coil. So its all brazing looks like, but the %45 silver should flow really nice.
I'll be posting a diagram soon.

UPDATE: Found this quote from a really good read, "Actually it's just a "strainer" with nothing more then a screen inside. And yes the basic idea is that the larger internal volume of the strainer as compared to the 3/16"od tubing feeding into it, will allow the velocity to decrease, thereby letting the heavier liquid drop away from the gas. Same principle of any phase separator, this one just happens to be rather small (and cheap).

Of course an even better phase separator has the refrigerant entering from the side, taking advantage of centrifugal force (not just gravity) to separate the liquid from the gas."

-http://www.xtremesystems.org/forums/showthread.php?144007-Morphing-Air-Conditioner-into-Autocascade-System

The two or three main posters in the cited thread are regulars on the xtreme forum. They do this refrigeration "alchemy" for a living, so they can be a great help to you and the rest of us. Unlike other forums, these people have no problem with giving a straight answer to the questions that we have difficulty with. Especially with respect to design parameters of an "unconventional" nature.Reading lots of threads over there, as well as asking the right questions of the individual experts, helped me immensely in understanding the theory behind how these rigs do what they do.

That site is loaded with awesome info. I have spent countless hours lost in thread upon thread. Jeff the only piece of the puzzle I'm missing is what size and how long the call tube coming off the oil separator/ drier should be. I have .049 ID and some .028 ID. But I can buy what ever is best, I should be able to start building the system next week.

So my idea is to use 2 SUD115 piggy backed, discharge comes into the 1/4 of the first one, out the 1/4 and into the 1/4 of the next one and out again. With the oil lines running out the bottom of each, with one foot of .049 ID cap tube. Both joining into a single run of 10 feet of .028. These are just crazy guesstimations based on what I was thinking.

But I do believe that if I stay around 275-300 feet of 3/8 tubing that the oil will make it back to the compressor anyway though. Just trying to keep out as much as possible.

So the work begins! I picked up this window unit a while back.
http://ecorenovator.org/forum/attach...1&d=1442921182
And I broke it down, this poor machine needed a really good cleaning.
http://ecorenovator.org/forum/attach...1&d=1442921182
Here are the numbers for the compressor, note the pink sticker on the bottom, this guy ran on R410a with POE oil, so that is getting flushed out and replaced with mineral, though R290 is soluble with POE as well.
http://ecorenovator.org/forum/attach...1&d=1442921182
I pulled out what was once the evap and cleaned it up with some acid.
http://ecorenovator.org/forum/attach...1&d=1442921182
The reversing valve is in, still need to find a coil for it though. I had to do some research on this to make sure it would work. I was worried the valve wouldn't be able to switch the flow from the condenser to the fish tank coil while the compressor was running, but I was reassured it would by a HVAC tech, so we shall just wait and see. http://ecorenovator.org/forum/attach...1&d=1442921182
I needed to find my water line before the digging starts this Sunday. And boy was it deep.
http://ecorenovator.org/forum/attach...1&d=1442921182

More parts coming in soon!

a few fleabay listings:

Ranco L27 2003 Solenoid Coil for Reversing Valve 48" Wire Leads 24VAC 50 60 Hz | eBay

Ranco Invensys L30 83 Solenoid Coil 24 VDC for V1 V12 Reversing Valve Heat Pump | eBay

6421A20003K LG Kenmore Dehumidifier Reversing Valve Solenoid Coil 030719 Sanhua | eBay

Make sure you get one that will work with your controls. AC or DC, correct voltage.

Thanks Jeff! I'm going with 24VDC, just ordered it!
I found awesome news! People I'm talking with say that a 1-2 ton oil separator will work just fine on this build. So I ordered this beauty! Q E HVAC R Refrigeration Oil Separator 1 2" ODS New | eBay

Parts come in! First off is 20 on 316 stainless steel for the coil in the fish tank and 2 sizes of cap tube. (Might not need them for this build, but just wanted to be sure.)
http://ecorenovator.org/forum/attach...1&d=1442957544
Next is 5x SUD115 and 45% silver braze
http://ecorenovator.org/forum/attach...1&d=1442957544
And finally the 2 Inkbird Thermostat/relays
http://ecorenovator.org/forum/attach...1&d=1442957544

This build is going to have all the bells and whistles because I need to be able to really test it out to see if the 4 ton build will work as planned.

I found some interesting data on R600a. Looks like higher temps at lower pressure. I might shoot for a blend.

http://www.tecumseh.com/~/media/Nort...A-and-R290.pdf

I reworked the fan and figured out the crazy chinese wiring.
http://ecorenovator.org/forum/attach...1&d=1443137111

The copper came in!
http://ecorenovator.org/forum/attach...1&d=1443137111

I ordered the cheapest I could find. So I was happy to see some really well made tubing.
http://ecorenovator.org/forum/attach...1&d=1443137111

Digging has been pushed til NEXT sunday.

I guess this means you're not using the OEM power supply or onboard relays to control the fan or compressor any more. Make sure to fuse everything correctly.

As to the r600 (butane) issue, it has a vapor pressure a little less than r134 or r12. At evaporator saturation temps below freezing water, your suction pressure is going to be near 0 psig. At seawater freezing temp, evaporator pressure is below atmosphere. I doubt your compressor could move enough mass to keep its motor cool.

Since your compressor is made for r410a, it needs to see a suction pressure in that range to keep cool within its operating envelope. Discharge pressure is not so much an issue as far as the compressor is concerned. All it really cares about is temperature.

What I would do is install some piercing valves on the stock unit and run it like they built it. Slap some gauges on it and log suction and discharge pressure for both sides. Choke the airflow on each side separately and observe pressure changes. Run the bad boy at all speeds and measure away. This will give you a detailed snapshot of the operating envelope it was designed to survive within.

After a decent approximation is made, you can blend propane and butane together to get a mixture that will satisfy your suction pressure range while giving you good discharge and condensation temperature. Raw high-side pressure will be lower than that of r410a, which in my mind is a good thing. Less pressure means less stress on everything.

Jeff, yes I have decided to not use the control board for the fan. I will be sure to have fuses where needed and everything on a gfci.

That is a very good point about the butane. I will be careful on how I use it, if any at all. This system is mainly for heating anyway.
Sadly the unit was out of 410a when I got it. The unit had fallen out of a window and on some trash below that busted a hole in the condenser.

When I charge I am going to do like I did with the water heater and charge by outlet temp, BUT I will keep a close eye to make sure the suction side is high enough to provide needed cooling, that is the main reason I went with 3/8 instead of 1/4. Thank you for that advise, changing the "perfect" blend only matters if the system works right.

As far as cooling the compressor goes, I plan to place it right before the condenser coils so the cooler air is drawn over it. I need to post the diagram soon, but for now MORE STUFF CAME IN!

A couple cheap temp sensors to constantly measure discharge and suction temp. http://ecorenovator.org/forum/attach...1&d=1443235055

A few relays
http://ecorenovator.org/forum/attach...1&d=1443235055

The awesome and amazing QOS-12 Oil Separator!
http://ecorenovator.org/forum/attach...1&d=1443235055

And just for fun, a shot with the inspection camera down the inlet! The outlet looks the exact same way.
http://ecorenovator.org/forum/attach...1&d=1443235055

The building begins soon. I post some final diagrams and numbers soon as well.

Check out the ASHRAE series of books, especially the Fundamentals years. My early nineties copy, lists many properties of propane, butane, isobutane, and many others. They also have beautiful log(p)-h diagrams of each refrigerant saturation curve. Here is a a link to a pdf version. I'm not sure if it is still good, but I know there is one out there.

Ashrae Handbook Standards Download

Go to Abebooks.com for a hard copy. They make a lovely reference.

That is great! I wasn't sure if it would work. My best plan of attack for a oil return, was a sort of vortex separator on the discharge of the compressor, where oil would tend to fall to the bottom. A capillary tube would carry oil back to the compressor suction. I figure some sort of strainer would be advisable, in order to avoid plugging the capillary oil return line. I suspect that even a well designed system would compromise volumetric efficiency slightly, but would certainly be necessary for compressor health in some instances. Then again, keeping the heat exchanger walls cleared of oil, could improve thermal transfer too.

That's interesting. Thank you

marx290, thanks for the links, the link was down, but I did find a google drive through that same site with a GOLD MINE of info.
https://drive.google.com/folderview?...DQ&usp=sharing

I am just now fully learning the P-H diagrams. I was always a try try try try til it fails then try try try again til it work kinda guy. But I am putting tons of research into this build. So I knew I needed to start with some basics of the math/science behind it all.

Progress has been made!
So I started just loose fitting things. First the discharge on the compressor to the intake on the oil sep, not the best idea I know, see below. -1/2"-
http://ecorenovator.org/forum/attach...1&d=1443567070
And the discharge of the oil sep into the reversing valve -1/2"-
http://ecorenovator.org/forum/attach...1&d=1443567070.
I knew the discharge from the compressor would have too much vibration to have a straight run to the oi sep, so I fixed it with a big loop.
http://ecorenovator.org/forum/attach...1&d=1443567070
The evap(now the condenser) had 2 cap tubes, so 2 intakes, I saved the cap tube and brazed some 1/4" onto them.
http://ecorenovator.org/forum/attach...1&d=1443567070
Then I ran the 1/2" from one side of the discharge of the reversing valve to the 2 1/4" intakes on the condenser.
http://ecorenovator.org/forum/attach...1&d=1443567070
The 2 1/4" tubes fit perfectly inside the 1/2". BEFORE
http://ecorenovator.org/forum/attach...1&d=1443567070
Brazed thoroughly. DURING
http://ecorenovator.org/forum/attach...1&d=1443567070
I was going to clean it up and take another picture, but I decided to move it into place first, and of course picked up the still super hot 1/2" line...... needless to say I am pecking with 2 fingers in between icing the burns in between typing... http://www.pic4ever.com/images/169.gif

Any way, next question, how much oil do I add and do I add it to the oil sep or the compressor? All to poe was drained. I have been looking for a while for the answer, still searching now.
Also I'm think 1/4" is to large for oil return. Would 1/8" be better?

Howdy guys I got a lot more done thanks to the help of a GOOD friend.

First I swagged the 3/8" lines, its SO much easier than 1/4"
http://ecorenovator.org/forum/attach...1&d=1443789038
http://ecorenovator.org/forum/attach...1&d=1443789038
Then I laid out the line, brazed it all up, pulled a vaccum for several hours, made sure I had NO leaks, then zip tied about 20 bricks to the end that is going in the water.
http://ecorenovator.org/forum/attach...1&d=1443789038
http://ecorenovator.org/forum/attach...1&d=1443789038
http://ecorenovator.org/forum/attach...1&d=1443789038
Then the digging started, I got down to 9 feet deep in some places, but never less than 6 feet. When we got close to the pond the machine tried to slip and almost went for a swim, so I will have to dig about a 4 foot spot by hand.
http://ecorenovator.org/forum/attach...1&d=1443789038
http://ecorenovator.org/forum/attach...1&d=1443789038
http://ecorenovator.org/forum/attach...1&d=1443789038
http://ecorenovator.org/forum/attach...1&d=1443789038
I insulated 2 feet down as it came into the green house.
http://ecorenovator.org/forum/attach...1&d=1443789038

More dig pics
http://ecorenovator.org/forum/attach...1&d=1443789585
http://ecorenovator.org/forum/attach...1&d=1443789585
http://ecorenovator.org/forum/attach...1&d=1443789585
http://ecorenovator.org/forum/attach...1&d=1443789585
Just in case you are wondering I am purging as I braze, I have had lots of luck with R152A, it IS flammable but not as much as propane. And it makes for some very clean brazing. It also lets you know when the entire tube is leak free because the flames stop.
http://ecorenovator.org/forum/attach...1&d=1443789585

MEMPHIS91,

This is serious work you're doing here!

Thanks for the pix, they help 'make it real'.

Keep going!

-AC

Don't use fluorocarbons as purge gas since they can become very toxic if heated to high temperatures.

Thanks AC, I was only able to get the line going into the pond to 2.5 feet. The water from the pond kept me from going deeper. If I do the DX for the 4 ton unit I will be sure to find a way to get it deeper.
I still have a front yard that needs repairing and my field lines from the septic patched back up.

Wow really? OK that's good to know. Thank you. Wondering if I can use compressed air of I run it through a good food drier/filter?

I let everything settle in the pond, plus we had a really cold night. The temp at the end of the loop is 70F. That is better than I though it would be. I only need the green house to be 65F. So there should be some pretty good efficiency!

OK, how are you going to purge the air out of anything with air? Even if it highly filtered , dried, and bottled? Request denied, purge gas for brazing/refrigeration cannot be air. Unless the air contains no oxygen.

I see you have engaged the hyperdrive on this one again. Don't run into any planets or imperials on your way, captain Jake. May the entropy be with you.

Jeff, I might be making a noob mistake and calling it the wrong thing. When I said purging, I meant the very low pressure gas I use as I am brazing to keep the black soot stuff from forming on the inside of the pipe.
I know purging is also the process of running a higher pressure gas (like nitrogen) through the system to clean out any particles.
Sorry if there was confusion or I am just totally wrong on every point. lol
I was looking at this though http://www.amazon.com/PneumaticPlus-...ords=air+dryer

Thanks man! I should have it up and running next week, I still have to finish the electric fence around the hard red winter wheat I just planted, and put the wood stove back together. WINTER IS ALMOST HERE! :eek:

Nope, we're all on the same page with this one. Air is the thing that oxidizes the piping from within whenever you heat it up. At phase change, water expands to 1700 times its liquid volume. This why the purging (aka shielding} gas should be as inert and dry as possible, especially when brazing or welding. Most of the synthetic refrigeration gases decompose into nasty and toxic fractions and acids whenever they see high temperature and any moisture present acts as a catalyst (steam cracking process). If you are really poor, go to the party store and get a few balloons filled with helium. BB gun cartridges and paintball gun cartridges are also pretty good and cheap solutions as well.

Thanks for the pictures. I would like to see pictures of your green house and Aquaponics setup.
I would like to know more on what you will use to safely heat the fish tank water with this.
Nice work.

Jeff, THAT MAKES SENSE! I guess I thought it was the violent action of the brazing that forced the black stuff into the pipe, I was assuming any gas flowing out would stop this from happening, but since your wisdom has once again kept me from doing stupid things, I TOTALLY understand now. THANK YOU. I got some old paintball co2 tanks laying around. Could helium tanks (the pink ones) be a good option? I'm not sure how expensive they are.

pinballlooking, I will try to get some pictures of my setup posted soon. The basic idea is the condenser is 20 feet of 316 stainless steal coil in the bottom of the fish tank. Stainless has no effect of the fish. I should have that part finished by the end of the week.

I got some more done today. I went with 1/8" for the oil return line.
http://ecorenovator.org/forum/attach...1&d=1444087850

Well I didn't get to far today, I did get the reversing valve hacked. I clamped the suction side closed and extend the tube from the solenoid valve to the suction side of the compressor.
http://ecorenovator.org/forum/attach...1&d=1444173840
Here are the pictures of my AP setup. Got 8 barrel halves and 4 grow towers with a IBC tote and 35-40 brim. Been going for over a year now. This is only phase one, phase two will be 14 more barrel halves.
Water and air pump are both solar powered.
http://ecorenovator.org/forum/attach...1&d=1444173840
http://ecorenovator.org/forum/attach...1&d=1444173840
http://ecorenovator.org/forum/attach...1&d=1444173840
And the view at night when the LED lights come on.
http://ecorenovator.org/forum/attach...1&d=1444173840
:thumbup:

Thanks for posting pictures of your system. Do you get good growth over the winter? What temp does your water stay at?

I didn't get much done today I had a regulator on my oxygen bottles mess up.
pinballlooking, The system did ok last winter, but I was unable to keep my water warm. I will have the temp set to 65-70F this winter.

Pardon me for asking, but why did you close off the suction line of your reversing valve?

Because I am not switching the direction of flow. It will only heat, I just need it to switch from sending heat to the air condenser to the water condenser. But I still needed the suction to operate the valve.

Aha, that's what you're doing! Solenoid actuated switching of heat between your aquaponic fish tank and greenhouse airspace is brilliant. I assume your fish tank will have another dx coil in it, not a forced flow hx. When this dx coil is disconnected from the compressor discharge, its outlet will have discharge pressure present, which will tend to fill the coil with liquid backwards. In essence, the dx coil will act as a subcooling liquid receiver. This will affect your system charge and hold some oil as well. Considering your dx ground loop size, a suction line accumulator near the compressor would be a prudent addition.

Yes I though about the different size/pressure/temps on the air source/fish tank condensers. And yes it will be DX, 20 feet of 1/4" 316 stainless steel. The compressor has a small accumulator on it already and I'm going to add 2 loops into the 3/8 copper coming into the suction side. Do you think adding a full size larger accumulator would be needed?

I had a set back yesterday, but I got it fixed last night, and will post more pictures and a update tonight. (More tools had to be bought. :rolleyes::D;) )

Also I am cutting the dual cap tubes in half, therefore making 4 cap tubes. The idea behind this is I KNOW they will need to be shorter like with the HP Water Heater. This will allow me to crimp one shut without having to open the system again and again, then once I know the needed length, I'll make the prefect size new one and fine tune everything.

So today went MUCH better. The problem I ran into was that I cooked my reversing valve. I had been very careful but using map gas, but it just has WAY to wide a flame, and it takes much longer to heat up therefore heating the entire valve enough to cook the nylon o rings on the piston shuttle.

So I found the cheapest reversing valve I could find in town and picked up a nice torch set. :D:cool:
http://ecorenovator.org/forum/attach...1&d=1444430018


I got everything brazed back up!
http://ecorenovator.org/forum/attach...1&d=1444430018

And I started on the electric side of things.
From left to right. On/Off, High side and low side temps, and INK BIRD controllers that will be displaying air temp and fish tank water temp.
http://ecorenovator.org/forum/attach...1&d=1444430018

More to come soon.
Shalom

Got all the electric done, fan guard built (there will be a grate over the blades when I'm done), and the Discharge/suction gauges installed.
http://ecorenovator.org/forum/attach...1&d=1444697937
http://ecorenovator.org/forum/attach...1&d=1444697937
http://ecorenovator.org/forum/attach...1&d=1444697937