Hi everyone in the forum

[chemy]

I'm new here and I'm looking for help related with the suction pressure in a Mquay 18,000 minisplit unit which use R22. I charged the unit to about 72psi but it is not cooling enough. I read some posts in the site and I saw that there are many people with issues like the one I have. How did I know which pressure I have to set up my unit.

[Andy]

I'm new here and I'm looking for help related with the suction pressure in a Mquay 18,000 minisplit unit which use R22. I charged the unit to about 72psi but it is not cooling enough. I read some posts in the site and I saw that there are many people with issues like the one I have. How did I know which pressure I have to set up my unit.

Hi Chemy:)

72 psig seems high:( try lowering this to 60 to 65 psig (unless your ambient is very very high)

What is you condensing pressure

What temperature is the liquid line

And what temperature is you suction and discharge of the compressor.

Also has your unit enough duty to cool the room.

Kind Regards Andy:)

Kind Regards Andy:)

[puddleboy3]

Hi there and welcome to the forum! As andy says you cant just charge a system to pressure, there a few other things that have to be taken in to consideration ie suction superheat/discharge superheat. All basic refrigeration practice!