11,000 BTU DX GEO Heating

[MEMPHIS91]

I for sure did NOT burn up this reversing valve. I cut the suction side (middle bottom port) back open and I can make it move with the camera head of my inspection camera.

[MEMPHIS91]

Suction line to the pilot valve was blocked. I'm brazing everything back up and will charge it up again tonight.

[pinballlooking]

Glad you found the issue.

[jeff5may]

Awesome debugging skills demonstrated, Jake. You should take the hacker first class test soon. I have no doubt you would pass with distinction. Then you could take your skills anywhere and rule.

Seriously though, I am anxious to see if your 4way to 3way valve conversion is sufficient to assume control without any strange side effects. A single valve with one solenoid is a good example of "less is more". Again, I have my fingers crossed.

[MEMPHIS91]

I got everything put back together and it works great! No problems at all. I am still fine tuning everything. Playing with the charge and call tubes.

Thanks Jeff, is there such a test? Lol

More pictures and details soon.

[MEMPHIS91]

Just to go over exactly what kept this system from working perfectly as designed the first time was bad brazing on my part (again). This is the joint that was the issue (the one at the end of the white sucker stick ((this suckers are awesome! Yummy Earth, Organic Pops, Assorted Flavors, 50+ Pops, 12.3 oz (349 g) - iHerb.com))).

This is the old one.

I got the joint and tubing to hot and it pulled the braze into the tubing. Solution was to make the joint longer and shove the tubing deeper into the joint and hit it with quick heat, braze, and stop to let the joint cool between brazing each end.

I had the psi at 40 suction and 245 discharge this morning and it was heating well but I still was not getting my suction temp anything lower than 70F. I know this is ok but I would like to see it drop a lot to know I am really sucking the heat out of the ground.
So I was going to add more charge to increase latent heat but I should have waited til it was colder, it got up to 85F today and my system showed it.
Needless to say I can't fill any R290 or R600 when both at at 50 psi at room temp. I though about adding some R152A because its at 75psi at room temp. But I'll do more testing tonight and the next few days as it gets cooler.

Jeff, I can see NO liquid in the sight glass or anything crazy happen when I swap from air to fish tank condenser.

Only concern I have is that when I started it up this afternoon, TONS of liquid was flowing through the sight glass (it is right before the accumulator) for about 20 seconds. Is this normal? I can not think of why it would? Could it all be settling at the bottom?

Anyway, system WORKS as is. I'm still waiting on a built in amp/watt/volt meter to get here. As of this morning it was showing 3.5AMPS and discharge temp was 176F.

[MEMPHIS91]

15 seconds 6 pictures.








Is this normal? I'm guessing that very very little really ever makes it to the compressor.

[jeff5may]

Probably the butane that is not evaporated in the loop. The high pressure in the evaporator is not forcing a low enough boiling point on the butane. I have a sneaky suspicion that you have a lot of liquid butane living in the accumulator after the unit has run up to its balance point. It can only exist at these high pressures as a subcooled liquid, except the tiny fraction that dissolves in the propane due to partial pressure.

Propane Butane Mix - Evaporation Pressure

[MEMPHIS91]

Jeff, Sorry I totally forgot to say that after your suggestions about not using the R600 I decided not to. I mentioned it in a previous post to say that the pressures were about the same as R290.
So am I understanding this right? I need a higher suction pressure? I think that is the only way to get more flow/capacity. So I may open up my cap tube some and charge with a higher pressure gas. In which case I only have 2 options. R152A or R134A

[jeff5may]

Originally Posted by MEMPHIS91

Jeff, Sorry I totally forgot to say that after your suggestions about not using the R600 I decided not to. I mentioned it in a previous post to say that the pressures were about the same as R290.
So am I understanding this right? I need a higher suction pressure? I think that is the only way to get more flow/capacity. So I may open up my cap tube some and charge with a higher pressure gas. In which case I only have 2 options. R152A or R134A

Both of these gases have lower vapor pressures than propane. To pull lots of heat from the ground, either one would need less than 25 psi gauge pressure. For pure propane, you are probably a little overcharged already. For higher vapor pressures you need to go the other way, towards methane, ethane, ether and the like.

If you are trying to force feed your compressor more pressure to make it act like r410 you have your work cut out for you. In fact, there are no real substitutes for r410. It was engineering and management racking up hours of work that came up with the stuff in the first place. The closer gases to it in behavior will not run at the high pressures and burn things up if you force them to.