My CO2 is outside the fridge. I have two regulators. One goes to the kegs inside, one has a long hose outside. To force carbonate I crank that puppy up to 30 psi, and then put a bar stool in front of the fridge, put the keg across my legs and gently rock it back and forth for about 7 or 8 minutes. You can hear the CO2 going in. Then I hook it up to service pressure.
It works really well, the beer pours perfectly in a few hours. can see no negative effects.....