# Thread: What determines the static pressure?

1. ## What determines the static pressure?

or standing/still state/equalized refrigerant loop pressure of a stopped system.

If the entire system is at uniform temperature, it will be whatever the unit is at, so if you leave a window A/C in your trunk and its at 120F, the entire hermetic system will pressurize to 264 psi or so for HCFC-22

In the case of a split system where the condensing unit's sun baked to 120F and evaporator coil is at 90F, what can I expect the static pressure to be?

Lowest temperature point, highest point, or something in between?

For a package RTU in Phoenix, AZ on a 105F baked in the sun, is it unreasonable to assume it will reach 135F? (vapor pressure of R-22 is 315 psi).

This means you can leak test any component using nitrogen at whatever R-22 vapor pressure system is expected to see under normal design parameters, no? So for a RTU package, even if you don't know the maximum permissible pressure, its ok to pressurize the system to at least 315 psi, no?

2. Is this a drunken post? lol

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I wonder if the OP is the same guy that owns this pickup.

5. Measure the pressure when the system isn't running.....? Just kidding...here you go: http://www.youtube.com/watch?v=YkCXg...x=0&playnext=1

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Originally Posted by ICanHas
If the entire system is at uniform temperature, it will be whatever the unit is at, so if you leave a window A/C in your trunk and its at 120F, it's around 264 psi for HCFC-22

In the case of a split system where the condensing unit's sun baked to 120F and evaporator coil is at 90F, what can I expect the static pressure to be?

Lowest temperature point, highest point, or something in between?
If your trying to determine the type of refrigerant in the system (or air in system) what is wrong with that question? I would like the answer also.
He is referring to the static pressure of the refrigerant not the static pressure of the air.

8. I thought it was a good question.

The static pressure will be at or close to your outdoor temp(accuracy of gauges?). Since there will still be some liquid refrigerant in the condenser.

9. Wouldn't that be standing pressure?

10. never thought of hooking up my manometer

11. Originally Posted by timebuilder
Wouldn't that be standing pressure?
Oops... I may have missed a word, but when was talking about R-22 and pressure in psi instead of air in inches water, I'm sure you gys figured out what I meant.

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i agree with been. but what are you trying to determine with that measurement?

13. Ima smartazz

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