Dealing with noise when rendering inside a mesh

Yay, first post here.
I know that there are many tutorials for dealing with noise in general, but what can I do if my scene is completely inside a closed mesh? (a room, to be precise)

I’m using a few portals to guide Cycles towards the windows, but there are several complex lighting setups inside.
There is a computer screen with emission (1 mesh light), a lava lamp with SSS wax which is illuminated by an area light and is behind the lamp’s glass and two ceiling mounted lights, which are also mesh lights (+2 mesh lights).

Light can travel outside the room through two windows, which use a mix of transparency and glossiness.

I rendered a panoramic image from the center of the room with 484 AA samples, which took me 27 hours (on a GTX 650), but the noise is still terrible.
However, when I render the objects inside without the walls around, render times are drastically reduced and noise is kept very low, even with AA samples below 10.

My question is, how should I render it as an interior without going crazy with the sample count?

It’s a bit hard to comment on this without knowing more details. Especially if you have lights behind transparent/refractive surfaces it would e. g. be crucial to know the node setups for those surfaces’ materials and of course the render settings.

Any chance you can post a simplified version of the scene for us to have a look?
Upload it e. g. to pasteall and post the download link here.

Sorry for the late reply, here is an upload:
The whole scene is pretty simple in terms of geometry and shaders, but the lighting setup may be overcomplicated.