Want the Davuluri Treatment but only have a R22 compressor? Don't feel left out
 

Earlier, I tried an experiment with running a R410a compressor on a R290 based mixture (ES22a, similar to R433b, the use of it in a R410a compressor being known as the "Davuluri Treatment") in order to avoid overstraining it with high condensing temperatures in my application. But what if you only have a R22 compressor? It turns out you can still do something similar.
3 ton air cooled residential heat pump uses R134a - YouTube
Now, R134a probably isn't the best choice since then you'll have to change the oil to POE and discharge temperature would greatly limit the temperature you can achieve. But a hydrocarbon mix intended for replacing R12 or R134a (such as R436a or ES12a) would work well. Hydrocarbons heat less on compression, meaning that a heat pump using it can go to higher temperatures before oil breakdown starts becoming a problem.