Can someone explain why low side/high side gauge pressure charts vary so much? For example I see charts that show, at 90 degrees, a low side of approx. 30 psi and high side of 225. Another chart will show 50 PSI and 260 PSI? One chart even allows for differences in humidity.

I've also seen the formulas for High Side Pressures: Ambient temp times 2 + 50. And 2.3, 2.4, or 2.5 times ambient temp.

I know engine RPM, airflow, spraying the condenser with water all have an effect on pressures. Bottom line I never know quite what to expect when I hook up a set of gauges to do a test or charge a system.

Thanks!

I've also seen the formulas for High Side Pressures: Ambient temp times 2 + 50. And 2.3, 2.4, or 2.5 times ambient temp.

I know engine RPM, airflow, spraying the condenser with water all have an effect on pressures. Bottom line I never know quite what to expect when I hook up a set of gauges to do a test or charge a system.

Thanks!

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