Have you looked at the Aeon multisensor 6? This can be recessed into the ceiling (and it’s damn small anyway).
Aeon multisensor 6
Yes, i did get one and i returned it. First thing - i cannot justify cutting a hole in the wall for this thing that needs to be extracted out. Plus it is huge compared to ZSE40 and according to people who had both - it works much worse in pitch black conditions. ZSE40 is a the smallest one on the market, just about an inch thick - so if placed above door frame you almost don’t see it. Until Lutron will make something good with an integrated sensor i will keep those battery non-sense things around.
I am really puzzled who runs marketing for those devices and how they decide what to put in those. It would make much more sense to combine motion detection with smoke detection and CO rather than have hygrometer and temperature. But, it is what it is.
Hmmm - the ZW100 is only 1.5 inches square - the ZSE40 is 2.25 square (according to the web search anyway). I guess the ZW100 is a little deeper - about 1.25 inches versus 1 inch for the ZSE40 - not exactly ‘huge’ in comparison, but I agree, it’s slightly deeper… I wonder if you were thinking of the multisensor 5 which was indeed pretty large?
I agree, but I think the issue is the sensors tend to be quite a bit bigger (at the moment), so if you want something really small, I don’t think it’s compatible.