Enclosed printers - do you actually keep the door shut for PLA?

I keep the enclosure sealed almost every single time, regardless of whether I am running PLA or ABS. My workspace is in an attached garage, so it can be quite cool, but even if it feels warm outside, the internal temperture can still drift significantly. For me, the biggest enemy is thermal inconsistency, not just a draft. I've learned from experience that leaving the door cracked open often results in subtle but noticeable issues like warping or that 'ghost' layer effect, even with forgiving materials. I prefer a stable environment, which is why I keep the glass door closed and rely on the printer's internal heating to keep the chamber consistent. I have a few large parts coming up that need to fit togehter perfectly, and that only happens when the thermal mass of the room and the print environment are locked down.

Even if you are printing something small and quick, maintaining that consistent temperature is a simple habit that pays off in the final quality. It makes the whole process much less stressful because you know the variables are controlled.

I actually tend to lean towards the door being open when I'm just running routine PLA parts, especially on the lower end of my speed range. I have a specific concern about oven-like conditions inside that small glass box, which I think can lead to warped corner pieces, even with PLA. My printer is an Ender 3 Plus setup, and I notice the internal temperature climbing pretty fast if the room is alredy at seventy degrees.

My habit is to keep the door propped open maybe a few inches, just enough to allow convection. This helps dissipate any trapped heat that might build up during long prints. It's not about preventing drafts, since that's just pushing the cold air in, but more about preventing a localized heat pocket from forming inside the chamber while the print is running.

I find that for small objects under a hundred grams, the difference is negligible, so I leave it open entirely. But if I'm doing somthing big, like a functional gear, I close it up for the duration becuase I know that's when the slightest thermal shift is most likely to cause issues.

One thing I'd add is that the window itself is probably a bigger variable than the door. Glass is a terrible insulator, so in winter you get a slow cold draft rolling off it and in summer direct sun can warm the whole desk, wich messes with the filament spool and the bed adhesion more than most people expect. I moved my printer off the sill-side of the room entirely and my first layers got noticeably more consistent. If you can, put a cheap thermometer next to the machine for a week and log it, the swing will surprise you.

For me it depends on print length more than material. Anything under a couple hours I leave the door open and it's been fine, but my long runs are a diffrent story. I did a 14 hour job last February with the door shut in a room that sat around 16C and the layers came out clean, whereas the same model with the door open showed curling on the tall thin sections. My rule now is door shut once the print is going to run overnight. One thing I'd check on yours is wheather the glass door sits tight when latched, mine had a slight gap at the top until I adjusted the hinge and that alone stopped most of the draft.