On 25 Aug 2006 00:38:34 -0700, "Akka" wrote:

Unfortunately, that appears to be what got us into our current problem,
as Calder was (I guess) writing with R12 in mind.

Yes, and every refrigerant has different properties.

It's because of him
that we filled the system until the sight glass was full, and
apparently overcharged. Also, he gives a table for ambient temp vs.
refrigerant pressure for R12 but nothing for R134a -- and it turns out
you can't use his table for R134a, even as a SWAG.

That is correct.


We finally bought the gauges but didn't think a 220V vacuum pump was a
worthwhile investment as we'll be returning soon to the 110V world. If
we open the system, we have to borrow or rent somebody else's pump. We
judge compressor and return-line temps by feel -- in the former case,
if you can touch it without burning your fingers it's not too hot, and
in the latter if it's cold but not frosting it's not too cold.

You absolutely can not properly adjust the system by feel. I'm
fortunate to have a neighbor who makes his living as a refrigeration
specialist. He has a detailed set of tables for each type of
refrigerant and uses electronic temperature guages in conjunction with
the tables and pressure guages to adjust the TXV. I used another
specialist in the north east to install the freezer. He used exactly
the same approach.