Close door ventilation grille?

Hello,

does anyone have tips on how to close ventilation grilles (see attachment) in bathroom doors? Ideally, for example, a panel closed on both sides? So far, I only have the idea of putting cardboard or possibly foam between the two parts of the ventilation grille.

I rented an apartment where two ventilation grilles are installed in each of two bathroom doors. In the bathroom with natural light, they are probably unnecessary. In the bathroom without a window, due to good fans and a leaky, old door, probably also.

Presumably, the ventilation grilles were once necessary because gas heaters were installed in the rooms (no longer today). Of course, cold air from the bathroom with natural light, as well as noise and odors, are disturbing.

I am new here and, as you can tell, not an experienced craftswoman :)

Thank you very, very much for a few tips

Melanie

Is the gas boiler no longer in the rooms or no longer in the apartment?

Is the gas boiler no longer in the rooms or no longer in the apartment?

There is no gas boiler in the apartment.

There has been a central heating system for decades, which also heats the water.

The best solution would be if the landlord exchanged the two doors for ones without ventilation grilles. Is that an option?

The best solution would be if the landlord exchanged the two doors for ones without ventilation grilles. Is that an option?

Why should a landlord just spend money in an apartment simply to satisfy a tenant's "petty" request? And then, if in doubt, install doors that don't even match the others visually (because the installed doors are old). I would, in coordination with the landlord, foam the openings and cover them with a film (if a reasonably matching one can be found).

If it is only about drafts/cold and not about sound, I would just tape it up (from the inside of the grid).