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the psi on your unit will fluctuate ...dirty filter will cause it to be lower'' high humidity will cause it to be higher,,, the perfect scenario is 95 outside, 75 inside with 50 percent humidity,,, then it should read 68 psi which is a 40 degree coil temp. only when these conditions are perfect will your psi be 68psi
Gas pressure for ac can be determined by the type of refrigerant not the model of the car. The outdoor temp will also be a major factor. 134a low side while its running could be around 35 psi to 45. While filling track temp of air supplying your vents and you shoul get a 15-20 degree differential form outdoor.
pressure readings vary depending on temperature, humidity, and other factors such as coil condition (inside and outside coils) ducting, other mechanical issues. The is no absolute readings for any one type of system, that said a ball park reading with an outdoor temp of 90deg and an indoor temp of 78deg it would be around 65 to 70 psi low side and 150 to 210 psi high side.
Hello, what is your high side pressure? A bad compressor will show abnormally high low side pressure with abnormally low high side pressure. That 45 low side pressure is low And superheat high. If you high side pressure is normal toma little above normal but the low side remains low you have a restriction in the system, that might be why it's not taking in tne freon. Let me know you high side pressure
The correct way is to evacuate the system,pull a vacuum then charge with a refrigerant scale. In lieu of that you can charge by pressure and get close. Normal operating pressure would be 68 psi on the suction side and about 225/275 on the high side. You do have to calculate the outdoor and indoor ambient temperature. At your 75 degree outdoor air a low side pressure of 60 psi or higher would be acceptable. Your 30/130 is too low. Add more refrigerant.
Make certain the indoor coil is clean and the fan motor is working correctly. Have the leak repaired.
low freon charge or your inside evap coils are dirty,,,check yourevap filter and replace if its dirty..also check your evaporater coils to see if its dirty,,,,,,,if its dirty you will need to flush and clean it...with coil cleaner and water......if all is clean and evap has good air flow..........your freon charge might be low......check your pressures hi and low.........hi side should be around 220 to 250 psi and low side should be 68 to 74 depends on the outdoor temp and indoor temps............have a certified hvac tech check the pressures.............
high side line is the small copper line
low side line is the bigger copper line............
The pressure changes with temperature, it is not a true gauge to ensure a proper charge.
You should have a 15 to 20 degree temp drop across the evap coil. (return air vs supply air)
Can you verify that the compressor is running?
Not the condenser, but the compressor located inside the condenser (outdoor unit)
it really sounds like it is still undercharged.
Check the temp drop, let me know what it is.
Also tell me what the outdoor ambient temp is.
( for example.... 98 degree outdoors with 85 degree indoor temp could result in pressures something like 325 on the high side and 75 or 80 on the low side.
With the exact same unit, but 80 degree outdoor temp combined with 70 degree indoor temp, your pressures could read 215 low side and 55 low side. Not to mention that more efficient units often have higher pressures on the low side because they have more coil space and remove heat more efficiently)
I'll try to give you the "Readers Digest" version.
First, make sure there is no ice build up on the evap. Light frost is O.K. as long as it does not effect air flow. (Very Important). All fans need to be running. Again, an air flow thing. There should be some product in the box but not too close to the evap. Again, an air flow thing.
The expansion device can effect your pressures to some degree i.e. Cap tube vs. TXV.
As a general rule of thumb, which I use almost everyday when it comes to pressures:
Low side is based on the temp difference between evap temp and condition space in the box. In freezers, it is almost always 10 degrees. If the box is 0 degrees then the evap needs to be at a minus 10 degrees. That is a pressure for R-404A of 24.5 psi. This only holds true when the temp in the box is approching set temp. I would say, about +10 degrees. 0 Degrees for the evap for R-404A is 33.5 psi.
High side should be ambient temp +30 degrees and then convert to a pressure for the refrigerant.
Example: 75 degrees in the room, +30 degrees equals 105 degrees. Now 105 degrees converted to a R-404A pressure is 253 psi. This will get you very close to the desired high side pressure.
I would look at low side first to see if it is within reason. Don't let the high side get too high. Increases the compression ratio and overworks the compressor.
Your icing problem could be a defrost issue and not a refrigerant charge issue.