Because of room temperature, I have to keep a prescription drug in the refrigerator. I take one once a day.
It takes about 4 seconds to open the lid, take out the pill, close the lid and return to the refer.
The refer door wants to close if it is not stopped.
Energy wise, is it better to keep the door open while I get the meds, or let it close and reopen it?
The refer has no fan.
Probably leave it open.
I would suspect that the action of opening and closing the door pumps more air out of the fridge than does just leaving it open for a moment.
I would guess the opposite. Every second the door is open, warm air is circulating through the fridge. Even without the fanning effect of the door, the temperature difference will cause natural convection.
I say we put it on a treadmill and test it!
When the door is opened the cold air will begin to fall out of the fridge. The door will have some fan effect but that is much smaller.