I am a homebrewer. My setup holds 6 5-gallon kegs. Previously I had my CO2 inside the chest freezer I've converted into keezer. I've recently acquired a 6th keg and there is not room for both 6 kegs and the CO2 tank inside the keezer.
When I purchase a CO2 refill it is generally around 1000PSI at room temperature and falls
to 600PSI a bit in the keezer. Following $PV=nRT$ this makes sense to me. A regulator on the tank exposes 30PSI to the rest of my system.
The keezer is set to keep the beer around 40F/4.4C. Depending on the style of beer I will force carbonate at 8PSI, 12PSI, 16PSI, or 30PSI (for sparkling water). I do this through a series of secondary regulators which can step down the pressure they're fed.
Now my question. If I move the CO2 tank and the regulators to the outside of the keezer unit will I have to adjust the displayed pressure to maintain the same effects? My gas will be at room temperature but it will be dissolved into refrigerated liquid. It's fed into the keezer through vinyl lines fed through holes drilled in the side.
edit: The 600PSI was a number I believe I've remembered incorrectly as was pointed out, it is too far a drop. The reading on the gauge does indeed fall but not that much. I don't believe the exact number there is of direct relevance to the question.
All carbonation pressures would be relative to atmospheric pressure, yes.