The Homemade Heat Pump Manifesto

[AC_Hacker]

Originally Posted by MN Renovator

...you really need to weigh in the charge because of the variable nature...

This may be all well & good, but if you start hacking your system, changing refrigerant, changing compressors, changing HXs, even changing appreciably the length or diameter of your lines that run from your compressor to the HXs, then the specified weight of the charge is no longer relevant.

At that point, going by pressure that applies to the refrigerant in question as I have done, or testing for performance as randen has done, or testing for super-heat and sub-cool as Vlad and GregC have done, can lead you out of the woods.

I hope that Vlad and GregC are reading this post and can weigh in on this matter, as it is important and they have a respectable amount of expertise on this very issue.

Best,

-AC_Hacker