HVAC Know It All - After a recent conversation regarding vacuums and units of measure I found this handy conversion table. 1" Hg Absolute is equal to about roughly 1/2 PSIA. Pressure
![PSIA vs PSIG: Differences | Conversion from PSIA to PSIG and PSIG to PSIA (With PDF) – What Is Piping PSIA vs PSIG: Differences | Conversion from PSIA to PSIG and PSIG to PSIA (With PDF) – What Is Piping](https://whatispiping.com/wp-content/uploads/2021/07/PSIA-vs-PSIG-1.png)
PSIA vs PSIG: Differences | Conversion from PSIA to PSIG and PSIG to PSIA (With PDF) – What Is Piping
![SOLVED: Given the barometric pressure of 14.7 psia (29.9 in. Hg abs), make conversions: thest 80 psig to psia and to atm 20 in, Hg vac to in: Hg abs and to SOLVED: Given the barometric pressure of 14.7 psia (29.9 in. Hg abs), make conversions: thest 80 psig to psia and to atm 20 in, Hg vac to in: Hg abs and to](https://cdn.numerade.com/ask_images/69f1469e659e4535bf3ef3b30e02685e.jpg)