Anybody Tried R407F In HeatPump Application?

[Freezebear]

Hello, long time reader, first time poster here. Like the title says, I am wondering if anyone has tried using R407F in a residential heatpump application. My friend's system is a 5year old, 3Ton, R22 system in excellent shape but sprung a leak in the evaporator so all the R22 is gone now. It has a TXV at the evaporator but uses a fixed-orfice outside for reverse-cycle operation.
I know I have to remove the compressor and drain the mineral oil and replace it with POE, no problem.
I have been digging around on the internet and have concluded that R407F would be the closest match for this application, but no technical info on anyone actually converting a R22 heatpump to R407F. Everyone seems to use R407C. But I read that R407C just isn't the best match for this system compared to R22. In this application, a small performance hit wont be that big of a deal since the house is fully insulated with sprayfoam. I have R407F on hand, but would have to buy a whole drum of R407C to only use 9 pounds of it.
So what do you think? Can it be done and what should I expect to encounter doing so?
Thanks.....

[Freezebear]

Nobody? Guess Im venturing off into uncharted territory with this. I have used it many times in supermarket retrofit jobs we do and besides the leaks that pop up after the retrofit, it runs pretty good. We dont see the demand cooling calling for cooling as often as it did on R22. We change every seal and gasket too, but it seems to be a hard ***** to contain those first few days on it.
Guess I will change all the schrader cores, pull the compressor and change the oil in it, then weigh in the charge and cross my fingers. Also will be using my Testo system analyzer to verify superheat and subcooling to see where it stands.

[install monkey]

i read on the website it is for medium/low temp applications

[Freezebear]

Yeah. That's what we use it for. So I was thinking since it does better at low temp than the others, he would get better performance in winter in heat than R407C. And would gain a little capacity over the R407C in summer too.