mini-split: orifice fixed expansion: Superheat measurement

[greg_mustang]

Hello,

Looking for advice for checking charge level on a 410a mini-split.
The unit is with an orifice metering/throtting device.

I am confused on whether or not i can use a superheat measurement (vs. value off table comparing inside and outside temp).
I once read that all these fixed metering mini-splits should measure superheat between 0-5 degrees.

Hoping someone can clarify this. I know that refrigerant on these is better charged by weight but i have no history of the install and have no scale. Of course i have guages, hoses and vacuum pump, temp sensor, and have done half dozen installs myself with good success over the years.

this unit specifically, is about 2 years old, cools 'moderately'...


Thanks,
Greg

 

[greg_mustang]

Nobody?

 

[shade]

Find the manufacturers website they will list the weight.

 

[greg_mustang]

Thanks but that didnt remotely answer my question.

Anyone know if its relevant to use superheat to check the charge of a mini-split with orifice metering device?

Greg

 

[56Mark]

I just put in a one ton mini 3 weeks ago. A friend that is an HVAC wizard came and checked the line set for leaks, pulled the vac and released the refrigerant. Out of curiosity he checked the superheat after we had it running. 3 degrees. Evap was running 36 degrees. So far it is great.

 

[LS6 Tommy]

Weighing the charge in is what is used on mini splits. They have a "critical charge". That being said, a single speed, fixed MD mini split should have 0°-5°F superheat under full load.

Tommy