Joe wrote:
I have a small leak in my evaporator. So, here comes the cooling
season again, and until I have the money to get the system repaired, I
need to add a charge. I've got the gauges hooked up, and measured the
ambient temperature at 82 deg F.

I remember that I used to just subtract x deg. from the ambient, and
add refrigerant until I reached that value on the low-side gauge.
However, I don't remember what that value is. IIRC, it was 35 or 40,
but the synapses don't fire like they used to.

Can anyone help me out here? I fail to understand the
superheat/subcool stuff, but the rule-of-thumb has served me well in
the past.

Joe

Don't know all that much about superheat and saturation temps , but when
mine got low from a return line leak (second season of use is when it showed
up) I put a clamp-on ampmeter on the compressor lead and charged it until it
read rated amps . I did have gauges hooked up , but can't remember now what
the exact readings were , but it's run flawlessly now for 8 or 9 years
without touching anything but the condensate drain line .
--
Snag
Daddy was an AC&R man ... after he retired from being an ET .