EcoRenovator - View Single Post - Propane (R-290) for heat pumps?

randallkc · 08-15-16, 09:47 PM

The biggest thing with R290 is the orifice difference. You can use a TXV built for R22 if you adjust it. That is what I do.

I tried to put in R290 to a capillary system without resizing the tubes. Total disaster! Very low super heat and sub cooling unless over charged. And even then was not right.

With pistons. I have not played with them much. But go smaller and play with it. I believe the orifice needs to be about 1/3 smaller than R22. R290 just is more liquid and flows easier.

As far as Oil, I don't want to risk going to synthetic oils that can wax up. I am happy with the old r22 oil. R290 does do a little better with synthetic but it also works fine with good old mineral oil. I don't want to rock the boat there.

I have only retro-fitted R22 systems. I took some ancient R22 systems from the 1980's that used capillary tubes. Dropped in new A coils and TXV valves. simply amazing! I have these two ton compressors almost 40 years old doing a great job! I have noticed a serious reduction in power consumption as well. Lower bills for units that I pay the utilities on. Most of that is the TXV but propane is slightly more efficient than R22.

Nothing like playing with a 40 year old AC system with nothing to loose. That is how I started to learn to hack R290. Love the stuff. I keep my old R22 systems alive off reclaiming R22 from systems I convert. If it has a A coil leak I replace with new A coil, TXV and R290. No way I will pay $600 a bottle for R22 or start replacing systems!

08-15-16, 09:47 PM	#276
randallkc Lurking Renovator Join Date: Jul 2016 Location: Kansas City Posts: 6 Thanks: 0 Thanked 1 Time in 1 Post	Propane The biggest thing with R290 is the orifice difference. You can use a TXV built for R22 if you adjust it. That is what I do. I tried to put in R290 to a capillary system without resizing the tubes. Total disaster! Very low super heat and sub cooling unless over charged. And even then was not right. With pistons. I have not played with them much. But go smaller and play with it. I believe the orifice needs to be about 1/3 smaller than R22. R290 just is more liquid and flows easier. As far as Oil, I don't want to risk going to synthetic oils that can wax up. I am happy with the old r22 oil. R290 does do a little better with synthetic but it also works fine with good old mineral oil. I don't want to rock the boat there. I have only retro-fitted R22 systems. I took some ancient R22 systems from the 1980's that used capillary tubes. Dropped in new A coils and TXV valves. simply amazing! I have these two ton compressors almost 40 years old doing a great job! I have noticed a serious reduction in power consumption as well. Lower bills for units that I pay the utilities on. Most of that is the TXV but propane is slightly more efficient than R22. Nothing like playing with a 40 year old AC system with nothing to loose. That is how I started to learn to hack R290. Love the stuff. I keep my old R22 systems alive off reclaiming R22 from systems I convert. If it has a A coil leak I replace with new A coil, TXV and R290. No way I will pay $600 a bottle for R22 or start replacing systems!