There is no centralised heating system (oil or gas). In terms of heating, the flat relies on two air conditioning units and a small wall mounted electric heating panel.
Given that I stayed in December, I felt it was too cold, I could sense humidity everywhere, dry air was coming out of the air conditioning units plus there was a strong musty smell. Of course, no heating whatsoever in the bathroom.
I understand that what I felt is subjective and the host told me that the air conditioning units is a satisfactory way of heating up a flat and no one had ever complained before. Fair enough - it’s up to you to decide whether or not that’s good enough for you.