saturated pressure of 134a

[moideen]

I have a cold room, required temp+3.evaporator sensor clamped on eva.centre coil. Refrigerant is r134a. evap.temperator shows 1c.room temp 10c.then td is ok.As convert the 1c saturation temp to pressure, should be get 44 psig. but gauge shows 15 psig. Anybody can clear
Moideen-Dubai

[nike123]

Either your temp sensor is inaccurate or influenced with surrounding air flow or you have high superheat at that place or your pressure gauge is not showing correct pressure.
I bet on that probe is not insulated from surrounding air.

[moideen]

Either your temp sensor is inaccurate or influenced with surrounding air flow or you have high superheat at that place or your pressure gauge is not showing correct pressure.
I bet on that probe is not insulated from surrounding air.

according to suction pressure(15 psig) evap.temp is -25c.then why does get the room temp 10c.it should be -16c.
moideen

[nike123]

according to suction pressure(15 psig) evap.temp is -25c.then why does get the room temp 10c.it should be -16c.


moideen

Not necessarily, what if we have restriction?

That is why we need full readings:
Evap air in temp
Evap air out temp
Low side pressure or saturation temp
Suction line temp at evap outlet

Cond air in temp
Cond air out temp
High side pressure or saturation temp
Liquid line temp at receiver or condenser outlet

[dirk]

You should not be working on refrigeration equipment alone.

With the information provided it is impossible to diagnose the problem, in future look at readings on all listed above and this may point you in the right direction.

[lana]

according to suction pressure(15 psig) evap.temp is -25c.then why does get the room temp 10c.it should be -16c.
moideen

If this was always true then life would be so much easier .

Check the parameters which Nike123 mentioned. Probably you don't get the required capacity out of the evaporator.
might be : wrong TEV, incorrectly adjusted TEV, pre-expansion in the liquid line .....

Cheers

[moideen]

thanks your replay.now getting required temp+3,so i dont have tension.there is no txv,discharge pressure access.my question was only saturated pressure-temp variation.