Is a multisplit air conditioner suitable for heating?

Or simply leave the window open at night.

On tropical nights, the open window does not help, apart from any noise and humidity that may be present.

Or simply leave the window open at night.

That doesn't always work because of the street or mosquitoes. There are also children who go to bed at 7 p.m., so it's not time for airing yet.

Open windows don't help during tropical nights, apart from any potential noise and humidity.

There have been no tropical nights here this year yet, not even during the entire last "summer." On Sunday night, the first summer night is expected, but only 21 degrees.
A bit of a draft in the evening, opening the window slightly at night currently results in 18 degrees in the bedroom here.

It just doesn't always work because of the street or mosquitoes. There are also kids who go to bed at 7 p.m., so ventilating at that time is out of the question.

There are mosquito screen windows against mosquitoes. And why can't you ventilate at 7 p.m.?

There are mosquito screens for windows. And why can't you ventilate at 7 pm?

You can't put mosquito protection on the skylight and at 7 pm the sun is still shining on it, which lets in more heat.