Ambient temp/ Pressure chart
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Can anyone point me in the right direction?
I found this link that is supposed to be a pressure/temperature chart for freeze 12.
http://freeze-12.com/f-12presstemp.html
It doesn't make any sense to me.
If someone understands this or knows of a chart that makes more sense, please let me know.
Thx.
I found this link that is supposed to be a pressure/temperature chart for freeze 12.
http://freeze-12.com/f-12presstemp.html
It doesn't make any sense to me.
If someone understands this or knows of a chart that makes more sense, please let me know.
Thx.
That is the only chart you will find. To use the chart to determine what your pressures and temperatures in an A/C system are doing.
Normally take the ambient temp add 30 to it on a normal a/c system. Find that number under the temp column the go across to the pressure column to the refrigerant you are using and that is what your discharge pressure should be. So if the ambient was 70 add 30 = 100 convert to pressure for freeze 12 and your discharge press should be around 116 psi. But remember this does not apply to auto A/C. Probaly with a car you can at least add 80 to 100 to your amb temp to find your discharge press. I never really worried about calculating this for a car, just informing you on what the chart means.
Your suction pressure is telling you what temperature the refrigerant in the evaporator is boiling, yes boiling at.(it took me about a year to comprehend this so don't even try)
In a normal a/c system your refrigerant temp in the evap is 36-40 f. In a car it can run as low as 25f or about 24 psi at highway speed or 2000 rpm's.
Your system pressures will also vary with your engine speed. At idle your suction press and supply air temp will rise and discharge will fall. At 2000 rpm your suction press and supply air temp will fall and the discharge will rise. So when you are checking and charging you system you should have a helper maintain at least 2000 rpm.
To make a long story short your suction should be around 24 and discharge around 325 (or lower because your hood is open and it's cooler around the engine) on an 80f day at 2000rpm and your air temp comming out of the center vent on hi max ac should be about 30 degrees colder than amb temp.
My fingers are tired and that concludes basic a/c 101.
good luck,
Gary.
Normally take the ambient temp add 30 to it on a normal a/c system. Find that number under the temp column the go across to the pressure column to the refrigerant you are using and that is what your discharge pressure should be. So if the ambient was 70 add 30 = 100 convert to pressure for freeze 12 and your discharge press should be around 116 psi. But remember this does not apply to auto A/C. Probaly with a car you can at least add 80 to 100 to your amb temp to find your discharge press. I never really worried about calculating this for a car, just informing you on what the chart means.
Your suction pressure is telling you what temperature the refrigerant in the evaporator is boiling, yes boiling at.(it took me about a year to comprehend this so don't even try)
In a normal a/c system your refrigerant temp in the evap is 36-40 f. In a car it can run as low as 25f or about 24 psi at highway speed or 2000 rpm's.Your system pressures will also vary with your engine speed. At idle your suction press and supply air temp will rise and discharge will fall. At 2000 rpm your suction press and supply air temp will fall and the discharge will rise. So when you are checking and charging you system you should have a helper maintain at least 2000 rpm.
To make a long story short your suction should be around 24 and discharge around 325 (or lower because your hood is open and it's cooler around the engine) on an 80f day at 2000rpm and your air temp comming out of the center vent on hi max ac should be about 30 degrees colder than amb temp.
My fingers are tired and that concludes basic a/c 101.
good luck,
Gary.
