no superheat, no subcooling

[02powerstroke]

how so? It has to do with the heat absorbed by the refrigerant and the vapor pressure of the refrigerant coming back to the compressor... Guess I am a little lost as to what you are looking for here for an answer

[waltervan]

Did I miss the Model Number if not I think we need it

[jpsmith1cm]

how so? It has to do with the heat absorbed by the refrigerant and the vapor pressure of the refrigerant coming back to the compressor... Guess I am a little lost as to what you are looking for here for an answer

Actually, it doesn't have as much to do with heat absorbed as it does with ********.

Damn. I almost gave away the answer.

[02powerstroke]

Greater subcooling

[jpsmith1cm]

Greater subcooling

If you have subcooling, what does that tell you?

What difference would that make in the system?

[02powerstroke]

?

[jpsmith1cm]

?

You don't understand what taking a subcooling reading tells you?

[02powerstroke]

Yes I do, but I'm driving so I am going to have to do this after bit

[jpsmith1cm]

Yes I do, but I'm driving so I am going to have to do this after bit

Drop the phone and hold onto the wheel!



Catch you later if I can.

[02powerstroke]

greater subcooling means that you you are below the saturation temp by so many degrees... waht this means is that the refrigerant can absorb more energy before it starts to evaporate... If you have more refrigerant, more subcooling and the same load, you will have less refrigerant turning to a vapor (vaporization) so your vapor pressure will be lower on the suction side of teh compressor... all it means is that you are getting more cooling out of your refrigerant...

Am I missing something without going into enthalpys?

[Southern Mech]

? hmmmm?? design pressures on manufacture label?/? = test pressure, not operating design.


now if we are talking design pressures for operating temps and pressures and they are that high, you have the wrong refrigerant.

[jpsmith1cm]

greater subcooling means that you you are below the saturation temp by so many degrees... waht this means is that the refrigerant can absorb more energy before it starts to evaporate... If you have more refrigerant, more subcooling and the same load, you will have less refrigerant turning to a vapor (vaporization) so your vapor pressure will be lower on the suction side of teh compressor... all it means is that you are getting more cooling out of your refrigerant...

Am I missing something without going into enthalpys?

You're overthinking.

In simple terms, if you measure subcooling, what do you know?

[02powerstroke]

Your refrigerant is a liquid

[ChaseAir]

Your refrigerant is a liquid

It gives you an idea of how much liquid is in the condenser coil. If you had a restriction in the evap area, you might accumulate more refrigerant on the condenser

[02powerstroke]

It gives you an idea of how much liquid is in the condenser coil. If you had a restriction in the evap area, you might accumulate more refrigerant on the condenser

thank you... that makes sense

[02powerstroke]

ok... I went back and tested it one more time.. here is what I ended up with

Suction Line Temperature ~ 60F
Suction Pressure - 83 PSI
Liquid Line Temp - 96F
Discharge Pressure 202psi
Refrigerant - R22

THe model of the condensing unit is a 38CKC042

[ChaseAir]

11 superheat. 6 subcool. It would help to know indoor wb db and delta t.

You have low subcool for sure. If it is a txv metering device, it is most likely undercharged. If it is a piston, you either have low airflow or too big of a piston.

[02powerstroke]

Indoor temp is 78F, will have to measure wet bulb. The consensing unit is a piston unit. This is an original split on a ranch that had the basement finished recently.

[jpsmith1cm]

Your refrigerant is a liquid

Exactly.


And what part of the system needs liquid to operate correctly?

[02powerstroke]

Evaporator coil