### How to Calculate System Superheat and Subcooling

ASSIGNMENT: Watch video and refer to text below         (

How to get superheat: Attach your temp probe to suction line at
condenser service valve suction line.

Write down suction line temp: Example 65 degrees

Example: 52 PSI

Determine saturation temp using pressure temp chart or your guages.

52 PSI equals 30 degrees sat temp.

Subtract saturation temp from line temp which will equal superheat

Example: 65 degrees minus 30 degrees equals 35 degrees of
superheat

Most of the time when you have this large of a superheat you are way
low on freon. Your target superheat for this example would be 13
degrees which means the evap coil is starved and you need to add
freon to bring the superheat down.
How to get subcooling: Attach you temp probe to liquid line at
condenser service valve liquid line.

Write down liquid line temp: Example 100 degrees

Example: 210 PSI

Determine sat temp using pressure temp chart or your guages.

210 PSI equals 105 degrees sat temp.

Subtract line temp from sat temp which will equal subcooling

Example: 105 degrees minus 100 degrees equals 5 degrees of
subcooling

Most of the time when you have this small of a subcooling amount you
are way low on freon. Your target subcooling for this example would
be 10 degrees which means the condenser coil is starved and you
need to add freon to bring the subcooling up.

January 18th, 2012  in Comments Off