Superheat

[wizzer]

Correct me if i'm wrong but does that mean for me to measure superheat at the evap i have 1 probe on the expansion side of the TEV and 1 probe at the coil exit in to the suction line, and is this with the evap fans on.

always eager to learn from good enginners.

regards

Wizzer

[frank]

To measure the superheat at the evaporator (amount of heat energy added to the refigerant after phase change) you need to determine the refrigerant pressure (using gauges), look this pressure up on a refrigerant properties chart (pressure versus temperature) and then measure the pipe temperature at the same point.

The pipe temperature will be higher than the chart value. Subtract one from the other and this will be the superheat reading.

[Temprite]

Correct me if i'm wrong but does that mean for me to measure superheat at the evap i have 1 probe on the expansion side of the TEV and 1 probe at the coil exit in to the suction line, and is this with the evap fans on.

always eager to learn from good enginners.

regards

Wizzer

That's the two temperature method.Some people use this method.

I prefer to use pressure temperature method as others have explained, as would most people.

[Actinide]

When taking your superheat temperature from the evap, your TXV superheat reading should come within the 4-7K range... If its under 4K your letting too much refrigerant into the evap, same goes if its over 7K your starving the evap.

With subcooling temperatures at the condensor, "correct me if im wrong" the subcooling should be between 2-5K over the condensor. Any less than 2K start looking at air flow restrictions on the coil, anymore than than 5K, low refrigerant charge, over sized condensor.

Hope this helps

Dale

[crit71]

Correct me if i'm wrong but does that mean for me to measure superheat at the evap i have 1 probe on the expansion side of the TEV and 1 probe at the coil exit in to the suction line, and is this with the evap fans on.

always eager to learn from good enginners.

regards

Wizzer

Yes Wizzer...you are correct. Forget about all the science behind it for now, aim for 6 degrees SH and your laughing.