Sdt??

[JtartD&L]

Talk to me as if im stupid. What is the saturated discharge temperature and how do you find it? It sounds to me like its a battle between words about the actuall deffinition of the term.

[US Iceman]

Yep, you are correct. The actual definition for SDT would be the saturation temperature of the refrigerant vapor at the discharge pressure of the compressor.

What you have to be careful with is how the person uses this term or what they think it means. Some think it is condensing temperature, others say discharge.

I'll stick with my version above.

SCT would be the saturation temperature of the refrigerant leaving the condenser at condensing pressure.

[JtartD&L]

So r-22 at 220psig has a sdt of 108? Or am i way off, This is byfar the most confusing subject.

[US Iceman]

Yes. If the compressor discharge pressure is 220 psig for R-22 then the SDT would be 108°F.

Now, since the condensing pressure should be slightly less than this (because of pressure loss in the discharge line) the SCT would be slightly lower also.

To simplify this; just use the pressure-temperature chart as you are doing now. For any pressure you read in a refrigeration system the saturation temperature should be equal to that corresponding pressure. If not, then you have to find out why.

[JtartD&L]

THANK YOU!! Why do people make this so hard. Pointless aspects of a useless phrase makes life so difficult.I appreciate it.

[US Iceman]

Why do people make this so hard?

Because it makes things so much more interesting trying to figure out what in the heck someone is talking about.

Seriously though, people tend to use terms they hear before and you have to be VERY careful in interpreting them. Some use SDT and SCT to mean the same thing and guess what???? they are actually two different points in a system.

When people use these interchangeably during system design you can end up with a messy system that doesn't work right.

[JtartD&L]

When i first read it i was thinking of the point in the condenser where the refrigerant meets its saturation point or where it begins to change state. And i was wondering how i was possible going to get that in a barrel condenser. Thanks for your help